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Objectives: Accurate epidemiological data are crucial for effective disease prevention and treatment. We conducted a large-scale survey to explore the thalassaemia prevalence and spectrum among the two major ethnic groups in Hainan Province., Methods: A total of 399,053 childbearing-age individuals of Li ( n  = 77,563) and Han( n  = 321,490) ethnic groups were recruited from 18 cities and counties in Hainan, and their thalassemia genotypes were systematically screened and statistically analysed., Results: This study revealed a significantly higher thalassaemia carrier rate in the Li (55.39%) than that in the Han (13.13%). Specifically, the carrier rate of α-thalassaemia was 46.39% in the Li and 10.02% in the Han. The predominant α-thalassaemia mutations were - α 3.7 and - α 42. in Li, whereas the main mutation were - SEA and - α 4.2 in Han. For β-thalassaemia, the carrier rates were 1.68% in Li and 2.38% in Han, with CD41-42(-CTTT) the most prevalent mutation in both groups. The carrier rates of β-/α-compound thalassaemia were 7.32% in Li and 0.73% in Han. Additionally, there were regional differences in the distribution of thalassemia among the Li and Han within Hainan Province., Conclusion: Epidemiological characteristics and molecular spectrum of thalassaemia among the Li and Han ethnic groups in Hainan were revealed in this study. These findings can provide a scientific basis to develop and implement prevention strategies for thalassaemia in Hainan.

Objective: The α-globin fusion gene between the HBA2 and HBAP1 genes, is clinically important in thalassemia screening because this fusion gene can cause severe hemoglobin (Hb) H disease when combined with α 0 -thalassemia (α 0 -thal). In this study, we evaluate the red blood cell parameters of α-thalassemia fusion gene in southern China., Method: Study samples suspected of α-thalassemia fusion gene were collected and confirmed by PCR-sequencing from one medical lab center in southern China. Their genotypes and phenotypes were analyzed., Results: A total of 266 cases of α-thalassemia fusion gene were confirmed in our lab from 2017 to 2023, most of them were from Hainan province (169 cases) and Huadu district of Guangzhou (21 cases), the nationality of 143 cases from Hainan was identified, with 71.3% (102/143) being from the Li minority. The Hb, MCV, MCH for αα/(αα) fusion in adult males were 143.5±11.83g/L, 81.51±4.39 fl, and 26.26±1.29 pg, respectively; and in females, they were 126.69±12.89 g/L, 80.10±4.05 fl, 25.8±2.04 pg, respectively. All 12 cases (αα) Fusion / -- SEA showed anemia with decreased Hb, MCV and MCH., Conclusion: The carriers of α-globin fusion gene heterozygotes are clinically silent and exhibit an α + phenotype. Individuals with (αα) Fusion / --SEA show apparent anemia. This α-globin fusion gene is relatively common in southern China, specifically among the Li minority of Hainan province. Therefore, it should be taken into account for genetic counseling purposes.

Objective: To analyze the genetic test results of 378 patients suspected of thalassemia., Methods: 378 suspected thalassemia patients in Shaoxing People's Hospital from 2014 to 2020 were selected and venous blood was tested using Gap-PCR and PCR-reversed dot blottin. The distribution of genotypes and other information of gene-positive patients was observed., Results: Thalassemia genes were detected in 222 cases, with an overall detection rate of 58.7%, of which 41.4% were α deletion type, 1.35% were α dot, 52.7% were α thalassemia, and 4.5% were αβ complex type. Among the 86 people with provincial household registration, the α-thalassemia gene accounted for 65.1% and the β-thalassemia gene accounted for 25.6%. Follow-up found that Shaoxing nationality accounted for 53.1% of positive patients, of which β-thalassemia gene accounted for 72.9% and α-thalassemia gene accounted for 25.4%; other cities in the province accounted for 8.1% of the total. Other provinces and cities accounted for 38.7%, most of which were from Guangxi and Guizhou. Among all positive patients, the most common α-thalassemia genotypes were --sea / αα, --α / αα,--α 3.7 4.2 / αα , --α3.7 / --sea. The most common mutations in β-thalassemia were IVS-II-654, CD41-42, CD17 and CD14-15., Conclusion: The thalassemia gene carrier status was sporadically distributed outside the traditional thalassemia high prevalence areas. The local population in Shaoxing has a high detection rate of thalassemia genes, and the genetic composition is different from the traditional high prevalence area of thalassemia in the south.

Objective: To investigate the genotype, mutation type, and ethnic distribution characteristics of thalassemia in the population of Hechi area, Guangxi, and to provide a reference basis for prevention and control of thalassemia and eugenic counseling in the region., Methods: Gap-polymerase chain reaction (gap-PCR) and reverse dot blot (RDB) were used for genetic testing on suspected thalassemia persons, and the results were analyzed., Results: Among 29 136 samples, a total of 17 016 (58.40%) positive samples for thalassemia genes were detected, with a higher detection rate in males than in females (χ 2 =49.917， P < 0.001). The detection rates of thalassemia genes were significant different among Zhuang, Han, Yao, Mulao, and Maonan ethnic groups (χ 2 =546.121, P < 0.001). The α-thalassemia genotypes were mainly -- SEA /αα (16.67%), -α 3.7 /αα (8.90%), α CS α/αα (6.00%). Additionally, four rare genotypes were detected, including -- THAI /αα (47 cases), HKαα/αα (2 cases), -- SEA /-α 21.9 (2 cases), and -- THAI /α CS α (1 case). The β-thalassemia genotypes were mainly β CD17 /β N (7.49%), β CD41-42 /β N (6.70%), β CD71-72 /β N (0.44%). 108 cases of moderate and severe β-thalassemia were detected, of which 81 cases had a history of blood transfusion, the transfusion frequency of 60 cases was more than 10 times/year, and 10 cases received bone marrow transplantation., Conclusion: Thalassemia in Hechi area is predominantly deletion type -- SEA /αα, the detection rate of thalassemia in ethnic minorities is higher than that in Han population. In this area, moderate and severe β-thalassemia have certain incidence, these patients mostly need regular blood transfusion and iron removal treatment, and very few patients have received bone marrow transplantation. This study provides a certain reference basis for prevention and control of thalassemia and eugenic counseling in the region.

Objective: To investigate the epidemiological characteristics and mutation spectrum of monogenic diseases in Chinese population through a large-scale, multicenter carrier screening., Methods: This study was conducted among a total of 33 104 participants (16 610 females) from 12 clinical centers across China.Carrier status for 223 genes was analyzed using high-throughput sequencing and different PCR methods., Results: The overall combined carrier frequency was 55.58% for 197 autosomal genes and 1.84% for 26 X-linked genes in these participants.Among the 16 669 families, 874 at-risk couples (5.24%) were identified.Specifically, 584 couples (3.50%) were at risk for autosomal genes, 306(1.84%) for X-linked genes, and 16 for both autosomal and X-linked genes.The most frequently detected autosomal at-risk genes included GJB2(autosomal recessive deafness type 1A, 393 couples), HBA1/HBA2(α-thalassemia, 36 couples), PAH (phenylketonuria, 14 couples), and SMN1(spinal muscular atrophy, 14 couples).The most frequently detected X-linked at-risk genes were G6PD (G6PD deficiency, 236 couples), DMD (Duchenne muscular dystrophy, 23 couples), and FMR1(fragile X syndrome, 17 couples).After excluding GJB2 c.109G>A, the detection rate of at-risk couples was 3.91%(651/16 669), which was lowered to 1.72%(287/16 669) after further excluding G6PD.The theoretical incidence rate of severe monogenic birth defects was approximately 4.35‰(72.5/16 669).Screening for a battery of the top 22 most frequent genes in the at-risk couples could detect over 95% of at-risk couples, while screening for the top 54 genes further increased the detection rate to over 99%., Conclusion: This study reveals the carrier frequencies of 223 monogenic genetic disorders in the Chinese population and provides evidence for carrier screening strategy development and panel design tailored to the Chinese population.In carrier testing, genetic counseling for specific genes or gene variants can be challenging, and the couples need to be informed of these difficulties before testing and provided with options for not screening these genes or gene variants.

Objective: To analyze the gene mutation types and frequence of thalassemia patients in Jingzhou area., Methods: A total of 721 suspected thalassemia patients who were visited in Jingzhou Central Hospital from June 2019 to June 2022 were selected as the research objects. There were 204 males and 517 females. PCR-reverse dot hybridization method was used to analyze the types and frequencies of 23 common α or β thalassemia gene mutations., Results: Among the 721 patients with suspected thalassemia, 228 cases were positive for α or β thalassemia gene, with a total positive rate of 31.62%, including 87 cases of α-thalassemia, accounting for 38.16%, and 140 cases of β-thalassemia, accounting for 61.40%. There was 1 case of α β complex thalassemia, accounting for 0.44%. A total of 4 types of α-thalassemia gene mutations were detected, all of which were deletion types, including αα/-- SEA (64/87, 73.56%), αα/-α 3.7 (14/87, 16.09%), -- SEA /-α 3.7 (7/87, 8.05%), αα/-α 4.2 (2/87, 2.30%). Among 140 patients with β-thalassemia, 138 were pure heterozygotes, and the genotypes of IVS-II-654M (63/140, 45.00%), CD41-42M (34/140, 24.29%), CD17M (18/140, 12.86%) and CD27-28M (10/140, 7.14%) accounted for 89.29% of all mutations (125/140), 2 cases of double heterozygosity (2/140, 1.43%) were found, no homozygous β-thalassemia were detected; 1 case of αβ complex thalassemia with genotype -α 3.7 / IVS-II-654M was found. The incidence of difference types of thalassemia was statistically significant (χ 2 =194.250, P < 0.001). The percentage of positive thalassemia genes was not significantly difference between male and female suspected patients (χ 2 =0.199, P =0.655)., Conclusion: The α-thalassemia gene mutation in Jingzhou area is dominated by αα/-- SEA , and the IVS-II-654M mutation is more common in β-thalassemia, and α β complex thalassemia is relatively rare, which can provide a reference for the formulation of prevention and treatment measures for thalassemia in Jingzhou area.

Thalassemia is a highly prevalent hematologic disease in Guizhou, China. This study aimed to determine the epidemiological characteristics of thalassemia in couples at childbearing age and assess the neonatal risk of thalassemia in this subpopulation. A cohort of 4481 couples at childbearing age were recruited for thalassemia carrier screening by both traditional hematological tests and next-generation sequencing. Of them, 1314 (14.66%) thalassemia carriers were identified, including 857 (9.76%) α-thalassemia, 391 (4.36%) β-thalassemia, and 48 (0.54%) composite α and β-thalassemia. A total of 12 α-globin gene alterations and 16 β-globin mutations were detected, including four novel thalassemia mutations. SEA was the most common α-thalassemia genotype (26.86%), CD41-42 the most common β-thalassemia genotype (36.57%), and αα/- α3.7 + CD41-42 the most common composite α- and β-thalassemia genotype (18.75%). Ethnically, the Zhuang had the highest rate of thalassemia gene carriers among the ethnic groups. Geographically, Qiannan had the highest rate of thalassemia gene carriers. In addition, 38 of the 48 couples with composite α- and β-thalassemia were high-risk thalassemia carriers, and 4 carrying the -SEA/αα gene needed fertility guidance., (© 2024. Japanese Society of Hematology.)

Background: Thalassemia is an inherited hemolytic disease, the complications and sequelae of which have posed a huge impact on both patients and society. But limited studies have investigated the molecular characterization of α- and β-thalassemia in children from Guizhou, China., Methods: Between January 2019 and December 2022, a total of 3301 children, aged 6 months to 18 years, suspected of having thalassemia underwent molecular analysis., Results: Out of the total sample, 824 (25%) children were found to carry thalassemia mutations. The carrier rates of α-thalassemia, β-thalassemia, and α + β-thalassemia were determined as 8.1%, 15.6%, and 1.3%, respectively. Approximately 96.5% of the α-thalassemia gene mutations were --SEA (51%), αα CS (20.9%), -α 3.7 (19.6%), and -α 4.2 (5.0%). The most prevalent mutations of β-thalassemia were β CD17(A>T) (41.5%), β CD41-42(-TTCT) (37.7%), and β IVS-II-654(C>T) (11.3%). Additionally, we identified rare cases, including one case with αα Hb Nunobiki /αα, two cases with triplicated α-thalassemia (one case with ααα/ααα and β CD41-42 /β N and the other with ααα -3.7 /αα and βE CD26 /β N ), and also one case with α Q-Thailand α/-α 4.2 and β CD41-42 /β N ., Conclusions: Our study findings provide important insights into the heterogeneity of thalassemia carrier rates and molecular profiles among children in the Guizhou region. The findings support the development of prevention strategies to reduce the incidence of severe thalassemia in the future., (© 2024 The Authors. Journal of Clinical Laboratory Analysis published by Wiley Periodicals LLC.)

Objectives: As one of the most common hereditary diseases, thalassemia affects a large number of people in China. The aim of this study was to investigate the feasibility of a method based on next-generation sequencing (NGS) for screening of thalassemia carriers among high school students in the Shaoguan area., Materials and Methods: The NGS-based method was performed using 25,910 high school students recruited from 38 schools. The screening yield was systematically analyzed. Before screening, a lecture on how the disease is inherited, the symptoms of thalassemia, and how to prevent it was given to 28,780 students., Results: Implying successful delivery of information on the disease, 90.03% (25,910 of 28,780) of the students agreed to join this program for thalassemia screening. A thalassemia carrier rate of 15.99% (4144 of 25,910) was found. Also, 69 rare genotypes (28 of α-thalassemia and 41 of β-thalassemia) and 9 novel variants were identified., Conclusions: This NGS-based method provided a feasible platform for high school population thalassemia screening. Combined with a clinical follow-up strategy, it could help eventually to prevent the births of affected children., Competing Interests: Declaration of conflicting interestsThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Background: Shenzhen is one of the most populated metropolises in southern China where thalassemia is highly prevalent. The prevention of thalassemia inheritance is an ambition of child-bearing couples., Methods and Results: A total of 22,098 peripheral blood samples were collected from 11,049 potentially at-risk couples of childbearing age from Shenzhen. Thalassemia mutations were determined by PCR-based flow-through hybridization. The results identified 45.02% of the participants (9948 out of 22,098) as harboring globin gene mutations, distributed into 18 α-thalassemia alleles detected in 71.48% (7111 out of 9948) and 15 β-thalassemia alleles detected in 32.68% (3252 out of 9948) of all mutant individuals, among which 415 individuals carried both α- and β-thalassemia alleles. The most frequent phenotypes for α-globin variations were -- SEA /αα (63.37%), -α 3.7 /αα (18.66%), and -α 4.2 /αα (7.31%), and those for β-globin variations were β 41-42 /β N (34.96%), β 654 /β N (28.11%), and β 17 /β N (13.84%). A total of 970 high-risk couples who could possibly give birth to offspring with thalassemia intermedia or major were identified. In addition, the hematological indices were compared among thalassemia genotypes. Significant differences in MCH, MCV, Hb A, and Hb A2 levels among α-thalassemia minor (α+), trait (α0), and intermediate phenotypes (P < 0.05) and between β E /β N and the other β-thalassemia phenotypes (P < 0.05) were found. Moreover, GAP-PCR and next-generation sequencing further identified 42 rare mutations, 13 of which were first reported in the Chinese population. A novel mutation in the β-globin gene (HBB: c.246 C > A (rs145669504)) was also discovered., Conclusions: This study presented a comprehensive analysis of thalassemia variations in a population from Shenzhen and may offer valuable insights for thalassemia control and intervention strategies in this area., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

Objective: To investigate the gene mutation and genotype distribution of thalassemia in the population of childbearing age in Chongzuo area of Guangxi., Methods: Six α-thalassemia and 17 β-thalassemia gene mutations common in Chinese were detected by gap-polymerase chain reaction (gap-PCR) combined with agarose gel eletrophoresis and reserve dot bolt hybridization in 29 266 cases of child-bearing age suspected of thalassemia., Results: A total of 19 128 (65.36%) cases were identified with thalassemia. The detection rate of α-thalassemia, β-thalassemia and α-combining β-thalassemia was 45.25% (13 242/29 266), 15.47% (4 526/29 266) and 4.65% (1 360/29 266), respectively. A total carrying rate of 8 kinds of α-thalassemia gene mutations was 26.74% (15 649/58 532), including 12.51% for -- SEA , followed by 5.70% for -α 3.7 , and 0.24% for -- Thai . Among 32 α-thalassemia genotypes, the most common five were -- SEA /αα, -α 3.7 /αα, α CS α/αα, -α 4.2 /αα and α WS α/αα, accounting for 47.27%, 18.31%, 8.56%, 8.52% and 7.91%, respectively, as well as 0.97% for -- Thai /αα. A total carrying rate of 13 kinds of β-thalassemia gene mutations was 10.07% (5 897/58 532), including 3.63% for CD41-42 , followed by 2.55% for CD17 , and 0.003% for -50 (G>A). Among 17 β-thalassemia genotypes, the most common six were CD41-42/N , CD17/N, CD71-72/N, CD26/N, 28/N and IVSI-1/N , accounting for 36.15%, 25.81%, 9.43%, 8.18%, 8.09% and 7.75%. The homozygous genotype CD26/CD26 [hemoglobin (Hb): 121 g/L] and -28/-28 (Hb: 56 g/L) were respectively detected in one case, and double heterozygous genotype were detected in 5 cases, including 3 cases of CD41-42 /CD26 (Hb: 41 g/L, 51 g/L, 63 g/L, respectively), 1 case of -28/IVSI-1 (Hb: 53 g/L), and 1 case of CD71-72/CD26 (Hb: 89 g/L), in which patients with moderate or severe anemia had a history of blood transfusion. Among 104 α-combining β-thalassemia genotypes, the most common were -- SEA /αα, -α 3.7 /αα combining CD41-42/N and -- SEA /αα combining CD17/N , accounting for 12.13%, 9.63% and 9.26%, respectively. In addition, 1 case of -- SEA /-α 3.7 combining -28/IVSI-1 (Hb: 83 g/L) and 1 case of -α 3.7 /αα combining CD41-42 / CD41-42 (Hb: 110 g/L) were detected without history of blood transfusion, while 1 case of α WS α/αα combining CD41-42 /CD17 (Hb: 79 g/L) and 1 case of -- SEA /αα combining CD17/-28 (Hb: 46 g/L) were detected with history., Conclusions: The detection rate of thalassemia genes is high and the mutations are diverse in the population of childbearing age in Chongzuo area of Guangxi. The common deletion genotype is -- SEA /αα in α-thalassemia and CD41-42/N in β-thalassemia, and deletion genotype -- Thai is not rare. There is a certain incidence of intermediate and severe β-thalassemia, and most patients require transfusion therapy. The results are beneficial for genetic consultation and intervention of thalassemia.

Thalassemia is one of the most widely distributed monogenic disorders in the world and affects the largest number of people. It can manifest a wide spectrum of phenotypes from asymptomatic to fatal, which is associated with the degree of imbalance between α- and β-globin chains. Therefore, individuals with different genotypes could present with a similar phenotype. Genetic analysis is always needed to make a correct diagnosis. However, routine genetic analysis of thalassemia used in the Chinese population identifies only 23 common variants, resulting in many cases undiagnosed or being misdiagnosed. In this study, we applied a long-read sequencing-based approach termed comprehensive analysis of thalassemia alleles (CATSA) to 30 subjects whose hematologic screening results could not be explained by the routine genetic test results. The identification of additional variants and the correction of genotypes allowed the interpretation of the clinical phenotype in 24 subjects, which have been confirmed to be correct by independent experiments. Moreover, we identified a novel 8.4-kb deletion containing the entire HBB and HBD genes as well as part of the HBBP1 gene, expanding the genotype spectrum of β-thalassemia. CATSA showed a great advantage over other genetic tests in the diagnosis of thalassemia caused by rare variants., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier B.V.)

The study aimed to identify essential phenotype-modulating factors among the pre-existence of several important ones and clarify their measurable impact on the clinical severity of hemoglobin (Hb) E/β-thalassemia in a community-recruited population analysis. This prospective study was designed to compare modifiers between community- (less or no symptoms) and hospital-recruited individuals with Hb E/β-thalassemia. The formerly included couples previously assessed for prenatal thalassemia at-risk status at 42 community and 7 referral hospitals in Thailand through on-site investigations between June 2020 and December 2021. The control included Hb E/β-thalassemia patients undergoing transfusions. The Mahidol score classified disease severity. Beta-globin, α 0 -thalassemia (- SEA , - THAI ), α + -thalassemia (-α 3.7 , -α 4.2 ), Hb Constant Spring (α CS ) alleles, rs766432 in BCL11A, rs9399137 in HBS1L-MYB, and rs7482144-XmnI were evaluated. Modifiers were compared between 102 community- and 104 hospital-recruited cases. Alleles of β + , - SEA , -α 3.7 , α CS , and a minor allele of rs9399137 were prevalent in the community and mild severity groups (p < 0.05). Multiple linear regression analysis associated modulating alleles with -4.299 (- SEA ), -3.654 (β + ), -3.065 (rs9399137, C/C), -2.888 (α CS ), -2.623 (-α 3.7 ), -2.361 (rs7482144, A/A), -1.258 (rs9399137, C/T), and -1.174 (rs7482144, A/G) severity score reductions (p < 0.05). Certain modifiers must be considered in routine prenatal genetic counseling for Hb E/β-thalassemia., Competing Interests: Declaration of competing interest None., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background: PCR, Sanger sequencing and NGS are often employed for carrier screening of thalassemia but all of these methods have limitations. In this study, we evaluated a new third-generation sequencing-based approach termed comprehensive analysis of thalassemia alleles (CATSA) to explore the prevalence of thalassemia in the Dongguan region of southern China., Methods: 19,932 subjects were recruited for thalassemia screening and hemoglobin testing was performed for each of them. Routine PCR was performed for all the hemoglobin testing-positive subjects and CATSA was conducted for randomly selected subjects from hemoglobin testing-positive and negative subjects., Results: In the 2716 subjects tested both by PCR and CATSA, 2569 had the same results and 147 had discordant results between the two methods. Sanger sequencing, specially designed PCR and MLPA confirmed the results of CATSA were all correct. In total, CATSA correctly detected 787 subjects with variants while routine PCR correctly detected 640 subjects with variants. CATSA yielded a 5.42% (147 of 2716) increment compared with routine PCR. In the 447 hemoglobin testing-negative subjects, CATSA identified pathogenic variants in 12 subjects. Moreover, CATSA identified a novel deletion (chr16:171262-202032) in the α-globin gene cluster. As a result, the deduced carrier frequency of α-thalassemia,β-thalassemia and α-/β-thalassemia was 5.62%, 3.85% and 0.93%, respectively., Conclusions: Our study demonstrated CATSA was a more comprehensive and precise approach than the routine PCR in a large scale of samples, which is highly beneficial for carrier screening of thalassemia. It provided a broader molecular spectrum of hemoglobinopathies and a better basis for a control program in Dongguan region., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier B.V.)

To assess the effectiveness of three-level prevention and control of thalassemia, we routinely collect samples from transfusion-dependent individuals and perform genetic analysis. Here, we report on a 10-year-old boy requiring blood transfusions with routine thalassemia gene test results of αα/αα, and β CD41/42 /β N , but he had thalassemia-like changes in his appearance and a high need for frequent blood transfusions, suggesting a case of thalassemia major in childhood. Given these equivocal results, samples from the family members were collected for further analysis. A multiplex ligation-dependent probe amplification assay was used to detect a multicopy number variant of the α globin gene cluster in the proband. The variant was detected as a long fragment repeat of 380 Kb using CNV assay technique, which contains the entire α globin gene cluster, describing it as αααα 380 /αα. Analysis of family members suggested that both the brother and mother of the proband carried the variant, and both MCV and MCH values were reduced in carriers. Individuals carrying multiple copy number variants of the α globin gene cluster exist in the population. Individuals carrying such variants who are also heterozygous for the β 0 thalassemia variant result in an imbalance in the α/β chain ratio, potentially leading to the creation of individuals with a severe anemia genotype. Most secondary prevention and control laboratories currently do not include variants with increased α gene copy number in their testing, which is one of the blind spots of prevention and control efforts. In order to provide more accurate genetic counseling to test subjects, especially in regions with high rates of thalassemia carriage, testing laboratories should pay attention to individual genotype-phenotype matches to avoid the under-detection of such variants.

Hemoglobinopathies affect patients in the wider Mediterranean area consisting of 4 distinct subgroups: beta thalassemia major (TM), beta thalassemia intermedia (TI), sickle cell disease (SCD) and hemoglobin H disease (alpha thalassemia). The clinical spectrum varies from mild to severe. Complex interactions between genes and environmental factors form the clinical manifestations. There is an unmet need to clarify these multifactorial mechanisms. This is the first Greek study describing mutational alleles (HBB and HBA1/HBA2 gene variants) in 217 patients with hemoglobinopathies of two large centers in Greece (Larissa and Athens) and associating particular genotypes or gene variants with clinical manifestations (transfusion frequency, complications). Thus, the complex interplay between corresponding genotypes and phenotypes was investigated. Our results are in accordance with previous national studies with limited variations, due to regional prevalence of specific gene variants, as expected. It is also a description of the prevalence of hemoglobinopathies in the Greek population. The type and prevalence of beta and alpha globin gene variants differ significantly among countries. We also confirm the well-known observation of many studies that in our beta thalassemic or SCD patients, co-inheritance of variants in the alpha globin genes, leading to absence or reduction of alpha globin synthesis were associated with milder clinical course, whereas the inheritance of additional alpha genes (triplication) led to a more severe clinical phenotype. In cases in whom the genotype and phenotype did not correlate, factors like the function or modification of possible regulatory genes or additional nutritional-environmental effects should be investigated. KEY MESSAGES: • This is the first Greek study, fully molecularly defining the beta and alpha mutational alleles in 217 patients with hemoglobinopathies of two large centers in Greece and correlating particular genotypes or gene variants with clinical manifestations (transfusion frequency, complications). • In the beta thalassemic or SCD patients of our cohort, co-inheritance of variants in the alpha globin genes, leading to absence or reduction of alpha globin synthesis were associated with milder clinical course (confirmation of a well-known previous observation). • The inheritance of additional alpha genes (triplication) led to a more severe clinical phenotype (confirmation of a well known previous observation). • The function or modification of possible regulatory genes should be investigated in cases in whom the genotype and phenotype did not correlate., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

This systematic literature review assessed the global prevalence and birth prevalence of clinically significant forms of alpha- and beta-thalassemia. Embase, MEDLINE, and the Cochrane Library were searched for observational studies published January 1, 2000, to September 21, 2021. Of 2093 unique records identified, 69 studies reported across 70 publications met eligibility criteria, including 6 records identified from bibliography searches. Thalassemia prevalence estimates varied across countries and even within countries. Across 23 population-based studies reporting clinically significant alpha-thalassemia (e.g., hemoglobin H disease and hemoglobin Bart's hydrops fetalis) and/or beta-thalassemia (beta-thalassemia intermedia, major, and/or hemoglobin E/beta-thalassemia), prevalence estimates per 100 000 people ranged from 0.2 in Spain (over 2014-2017) to 27.2 in Greece (2010-2015) for combined beta- plus alpha-thalassemia; from 0.03 in Spain (2014-2017) to 4.5 in Malaysia (2007-2018) for alpha-thalassemia; and from 0.2 in Spain (2014-2017) to 35.7 to 49.6 in Iraq (2003-2018) for beta-thalassemia. Overall, the estimated prevalence of thalassemia followed the predicted pattern of being higher in the Middle East, Asia, and Mediterranean than in Europe or North America. However, population-based prevalence estimates were not found for many countries, and there was heterogeneity in case definitions, diagnostic methodology, type of thalassemia reported, and details on transfusion requirements. Limited population-based birth prevalence data were found. Twenty-seven studies reported thalassemia prevalence from non-population-based samples. Results from such studies likely do not have countrywide generalizability as they tended to be from highly specific groups. To fully understand the global prevalence of thalassemia, up-to-date, population-based epidemiological data are needed for many countries., (© 2023 The Authors. American Journal of Hematology published by Wiley Periodicals LLC.)

Background: Thalassemia is an extremely prevalent monogenic inherited blood disorder in southern China. It is important to comprehensively understand the molecular spectrum of thalassemia in an area with such a high prevalence of thalassemia before taking appropriate actions for the prevention and treatment of this disorder. Herein, we explored the clinical feasibility of using next-generation sequencing (NGS) for large-scale population screening to illustrate the prevalence and spectrum of thalassemia in Southern Jiangxi., Methods: Blood samples collected from 136,312 residents of reproductive age in Southern Jiangxi were characterized for thalassemia by NGS. A retrospective analysis was then conducted on blood samples determined to be positive for thalassemia., Results: In total, 19,827 (14.545%) subjects were diagnosed as thalassemia carriers, and the thalassemia prevalence rate significantly varied by geographical region (p < 0.001). A total of 40 α-thalassemia genotypes including 21 rare genotypes were identified, with -@- SEA /αα being the most prevalent genotype. 42 β-thalassemia genotypes including 27 rare genotypes were identified, with the most common mutation IVS II-654 C > T accounting for 35.257% of these β-thalassemia genotypes. Furthermore, 74 genotypes were identified among 608 individuals with combined α- and β-thalassemia. Notably, most individuals with rare thalassemia mutations had mildly abnormal hematologic parameters including microcytic hypochromia., Conclusions: Our findings demonstrate the great heterogeneity and diverse spectrum of thalassemia in Southern Jiangxi, emphasizing the importance and necessity of persistent prevention and control of thalassemia in this region. Additionally, our findings further suggest that NGS can effectively identify rare mutations and reduce the misdiagnosis rate of thalassemia., (© 2023. BioMed Central Ltd., part of Springer Nature.)

Introduction: Thalassemia is the most common monogenic disease in South and Southeast Asia. An accurate assessment of the relative frequency and composition of thalassemia mutations is important for the design of appropriate strategies to prevent the disease. In this study, we aimed to decode the molecular characterization of thalassemia mutations in Zhuhai region of southern China., Methods: A total of 8048 individuals who were potential thalassemia carriers were enrolled. Gap-polymerase chain reaction (Gap-PCR) and reverse dot-blot (RDB) hybridization methods were employed to detect common deletional and non-deletional thalassemia mutations. Multiplex ligation dependent probe amplification (MLPA) and Sanger sequencing were used to analyze and verify rare and complex mutations., Results: We diagnosed 3433 individuals as thalassemia carriers or patients. Of these, 2395 (69.76%) individuals with α-thalassemia harbored 13 α-globin gene mutations. The three most common α-thalassemia mutations were -- SEA (60.08%), -α 3.7 (20.62%) and -α 4.2 (9.25%). We diagnosed 903 (26.30%) individuals with β-thalassemia and identified 20 β-globin gene mutations, of which the three most frequent were CD41/42 (-TCTT) (38.10%), IVS-II-654 (C>T) (23.69%) and TATAbox-28 (A>G) (15.18%). In addition, we identified 15 rare thalassemia variants. We also summarized the association between the thalassemia genotype and hematological parameters, which demonstrated the broad phenotypic heterogeneity caused by globin gene mutations., Conclusion: This is the first survey of thalassemia molecular epidemiology and hematological phenotype in Zhuhai region. It uncovered a high prevalence and complex molecular spectrum of thalassemia. These findings can be used as a basis for thalassemia diagnosis, counseling and prevention management., (© 2023 John Wiley & Sons Ltd.)

Objective: To analyze the prevalence, genotype distribution and hematological characteristics of α,β-thalassaemia carriers in Huizhou area of Guangdong Province., Methods: 10 809 carriers of simple β-thalassaemia and 1 757 carriers of α,β-thalassaemia were enrolled as our study cohort. The hematological parameters were detected by automated blood cell counters and automatic capillary electrophoresis. Suspension array technology, gap-polymerase chain reaction (gap-PCR) and PCR-reverse dot blot were used for the genotyping of thalassaemia carriers., Results: The prevalence of α,β-thalassaemia in Huizhou area of Guangdong Province was 1.99%. A total of 62 genotypes were detected, and the most prevalent genotype was -- SEA / αα , β CD41-42 / β N (19.29%), the next was -- SEA / αα , β IVS-II-654 / β N (16.73%). Significant differences in mean corpuscular volume (MCV) and mean corpuscular hemoglobin (MCH) were found between different genotype groups for simple β-thalassaemia and α,β-thalassaemia. Violin plots showed that carriers with co-inheritance of β-thalassaemia and mild α-thalassaemia expressed the lightest anemia, and carriers with co-inheritance of β-thalassaemia and hemoglobin H (Hb H) disease expressed the most severe anemia., Conclusion: There is a high prevalence of α,β-thalassaemia in Huizhou area of Guangdong Province. Because of the lack of specific hematological makers for diagnosis of α,β-thalassaemia, it is necessary to distinguish it from simple β-thalassaemia by genotyping of α- and β-thalassaemia in order to correctly guide genetic counseling and prenatal disgnosis.

Background: Inherited blood disorders affect 7% of the population worldwide, with higher prevalences in countries in the "thalassemia belt," which includes Bangladesh. Clinical management options for severely affected individuals are expensive; thus, targeted government policies are needed to support prevention and treatment programs. In Bangladesh, there is a lack of data, in particular community-based estimates, to determine population prevalence. This study aims to estimate the prevalence of a wide range of hemoglobinopathies and their associations with anemia in a community-based sample of women and young children in rural Sylhet, Bangladesh., Methods: Capillary blood samples from 900 reproductive-aged women and 395 children (aged 6-37 months) participating in the Food and Agricultural Approaches to Reducing Malnutrition (FAARM) trial in two sub-districts of Habiganj, Sylhet Division, Bangladesh were analyzed for alpha thalassemia, beta thalassemia, and other hemoglobinopathies. We examined the association of each inherited blood disorder with hemoglobin concentration and anemia using linear and logistic regression., Results: We identified at least one inherited blood disorder in 11% of women and 10% of children. Alpha thalassemia was most prevalent, identified in 7% of women and 5% of children, followed by beta thalassemia and hemoglobin E in 2-3%. We also identified cases of hemoglobin S and hemoglobin D in this population. Having any of the identified inherited blood disorders was associated with lower hemoglobin values among non-pregnant women, largely driven by alpha and beta thalassemia. Pregnant women with beta thalassemia were also more likely to have lower hemoglobin concentrations. Among children, we found weak evidence for a relationship between hemoglobinopathy and lower hemoglobin concentrations., Conclusions: We found a high prevalence of alpha thalassemia among both women and children in rural Sylhet, Bangladesh-higher than all other identified hemoglobinopathies combined. Community-based estimates of alpha thalassemia prevalence in Bangladesh are scarce, yet our findings suggest that alpha thalassemia may comprise the majority of inherited blood disorders in some regions of the country. We recommend that future research on inherited blood disorders in Bangladesh include estimates of alpha thalassemia in their reporting for public health awareness and to facilitate couples  counseling., (© 2023. The Author(s).)

Introduction: Microcytosis and hypochromia result from deficient hemoglobin synthesis in red blood cells and are easily detected in a complete blood count test. These conditions are mainly due to iron nutritional deficiency, but may also result from some genetic diseases, such as thalassemia. The aim of this study was to determine the contribution of β- and α-thalassemia to these abnormal hematological phenotypes in a representative sample of adult individuals living in Portugal who participated in the first Portuguese National Health Examination Survey (INSEF)., Material and Methods: Among the 4808 INSEF participants, 204 had microcytosis, hypochromia or both. The corresponding 204 DNAs were screened for changes in the β-globin gene by next-generation sequencing and Sanger sequencing. In addition, α-thalassemia deletions within the α-globin cluster were investigated by Gap-PCR and multiplex ligation-dependent probe amplification., Results: In this selected subgroup of INSEF participants, 54 had α-thalassemia (26%), predominantly caused by the -α3.7kb deletion, and 22 were β-thalassemia carriers (11%) mainly due to point mutations in the β-globin gene previously known in Portugal., Conclusion: Thalassemia trait is a frequent cause of microcytosis or hypochromia in Portugal since this genetic condition was found in 37% of the investigated cases.

α-thalassemia is an inherited blood disorder that is most frequently found in Southeast Asian populations. In Thailand, molecular characterization can diagnose most patients with α-thalassemia; however, several atypical patients are also observed in routine analyses. Here, we characterized α-thalassemia mutations among 137 Hemoglobin H (Hb H) disease patients and three fetuses of Hb Bart's hydrops, a fatal clinical phenotype of α-thalassemia. Specifically, we performed multiplex ligation-dependent probe amplification (MLPA) followed by direct DNA sequencing. We noticed common genotypes in 129 patients and eight patients had rare Hb H disease caused by compound heterozygous α 0 -thalassemia (-- CR or -- SA deletion) with α + -thalassemia (-α 3.7 /-α 4.2 /α Constant Spring α). Furthermore, two affected fetuses had the -- SA /-- SEA and one had the -- CR /-- SEA genotypes. Next, we developed and validated a new multiplex gap-PCR and applied this method to 844 subjects with microcytic red blood cells (RBCs) from various parts of Thailand. The frequency of heterozygous α 0 -thalassemia was dominated by -- SEA 363/844 (43%), followed by -- THAI 3/844 (0.4%), -- SA 2/844 (0.2%), and -- CR 2/844 (0.2%) mutations. These findings suggest that aforementioned four mutations should be routinely applied to increase the effectiveness of diagnosis and genetic counseling in this region., (© 2023. The Author(s).)

Thalassemia is a Mendelian inherited blood disease caused by α- and β-globin gene mutations, known as one of the major health problems of Mediterranean populations. Here, we examined the distribution of α- and β-globin gene defects in the Trapani province population. A total of 2,401 individuals from Trapani province were enrolled from January 2007 to December 2021, and routine methodologies were used for detecting the α- and β-globin genic variants. Appropriate analysis was also performed. Eight mutations in the α globin gene showed the highest frequency in the sample studied; three of these genetic variants represented the 94% of the total α-thalassemia mutations observed, including the -α3.7 deletion (76%), and the tripling of the α gene (12%) and of the α2 point mutation IVS1-5nt (6%). For the β-globin gene, 12 mutations were detected, six of which constituted 83.4% of the total number of β-thalassemia defects observed, including codon β039 (38%), IVS1.6 T > C (15.6%), IVS1.110 G > A (11.8%), IVS1.1 G > A (11%), IVS2.745 C > G (4%), and IVS2.1 G > A (3%). However, the comparison of these frequencies with those detected in the population of other Sicilian provinces did not demonstrate significant differences, but it contrarily revealed a similitude. The data presented in this retrospective study help provide a picture of the prevalence of defects on the α and β-globin genes in the province of Trapani. The identification of mutations in globin genes in a population is required for carrier screening and for an accurate prenatal diagnosis. It is important and necessary to continue promoting public awareness campaigns and screening programs.

Introduction: The α-globin fusion gene between the HBA2 and HBAP1 genes becomes clinically important in thalassemia screening because this fusion gene can cause severe hemoglobin (Hb) H disease when combining with α 0 -thalassemia (α 0 -thal). Due to its uncommon rearrangement in the α gene cluster without dosage changes, this fusion gene is undetectable by common molecular testing approaches used for α-thal diagnosis., Methods: In this study, we used the single-molecule real-time (SMRT) sequencing technique to detect this fusion gene in 23 carriers identified by next-generation sequencing (NGS) among 16,504 screened individuals. Five primers for α and β thalassemia were utilized., Results: According to the NGS results, the 23 carriers include 14 pure heterozygotes, eight compound heterozygotes with common α-thal alleles, and one homozygote. By using SMRT, the fusion mutant was successfully detected in all 23 carriers. Furthermore, SMRT corrected the diagnosis in two "pure" heterozygotes: one was compound heterozygote with anti-3.7 triplication, and the other was homozygote., Conclusion: Our results indicate that SMRT is a superior method compared to NGS in detecting the α fusion gene, attributing to its efficient, accurate, and one-step properties., (© 2022 John Wiley & Sons Ltd/University College London.)

Objective: This study was aimed at investigating the carrier rate of, and molecular variation in, α- and β-globin gene mutations in Hunan Province., Methods: We recruited 25,946 individuals attending premarital screening from 42 districts and counties in all 14 cities of Hunan Province. Hematological screening was performed, and molecular parameters were assessed., Results: The overall carrier rate of thalassemia was 7.1%, including 4.83% for α-thalassemia, 2.15% for β-thalassemia, and 0.12% for both α- and β-thalassemia. The highest carrier rate of thalassemia was in Yongzhou (14.57%). The most abundant genotype of α-thalassemia and β-thalassemia was -α 3.7 /αα (50.23%) and β IVS-II-654 /β N (28.23%), respectively. Four α-globin mutations [CD108 (ACC>AAC), CAP +29 (G>C), Hb Agrinio and Hb Cervantes] and six β-globin mutations [CAP +8 (C>T), IVS-II-848 (C>T), -56 (G>C), beta nt-77 (G>C), codon 20/21 (-TGGA) and Hb Knossos] had not previously been identified in China. Furthermore, this study provides the first report of the carrier rates of abnormal hemoglobin variants and α-globin triplication in Hunan Province, which were 0.49% and 1.99%, respectively., Conclusion: Our study demonstrates the high complexity and diversity of thalassemia gene mutations in the Hunan population. The results should facilitate genetic counselling and the prevention of severe thalassemia in this region., (Copyright © 2023 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.)

Context.—: Identification of rare thalassemia variants requires a combination of multiple diagnostic technologies., Objective.—: To investigate a new approach of comprehensive analysis of thalassemia alleles based on third-generation sequencing (TGS) for identification of α- and β-globin gene variants., Design.—: Enrolled in this study were 70 suspected carriers of rare thalassemia variants. Routine gap-polymerase chain reaction and DNA sequencing were used to detect rare thalassemia variants, and TGS technology was performed to identify α- and β-globin gene variants., Results.—: Twenty-three cases that carried rare variants in α- and β-globin genes were identified by the routine detection methods. TGS technology yielded a 7.14% (5 of 70) increment of rare α- and β-globin gene variants as compared with the routine methods. Among them, the rare deletional genotype of -THAI was the most common variant. In addition, rare variants of CD15 (G>A) (HBA2:c.46G>A), CD117/118(+TCA) (HBA1:c.354&#95;355insTCA), and β-thalassemia 3.5-kilobase gene deletion were first identified in Fujian Province, China; to the best of our knowledge, this is the second report in the Chinese population. Moreover, HBA1:c.-24C>G, IVS-II-55 (G>T) (HBA1:c.300+55G>T) and hemoglobin (Hb) Maranon (HBA2:c.94A>G) were first identified in the Chinese population. We also identified rare Hb variants of HbC, HbG-Honolulu, Hb Miyashiro, and HbG-Coushatta in this study., Conclusions.—: TGS technology can effectively and accurately detect deletional and nondeletional thalassemia variants simultaneously in one experiment. Our study also demonstrated the application value of TGS-based comprehensive analysis of thalassemia alleles in the detection of rare thalassemia gene variants.

Background: The correlation between thalassemia and malignancies other than hepatocellular carcinoma (HCC) and the possible relationship between other hemoglobinopathies and tumor risk have been poorly evaluated., Methods: Eight Italian specialized centers evaluated the incidence of malignant neoplasms in hemoglobinopathies as well as their sites and features. The study cohort included 4631 patients followed between 1970 and 2021 (transfusion-dependent β-thalassemia, 55.6%; non-transfusion-dependent thalassemia, 17.7%; sickle cell disease, 17.6%; hemoglobin H disease, 8.3%)., Results: A total of 197 diagnoses of cancer were reported (incidence rate, 442 cases per 100,000 person-years). The liver was the most frequent site of tumors in both sexes, with a higher incidence (190 cases per 100,000 person-years) in comparison with the general population found in all types of hemoglobinopathies (except hemoglobin H disease). In recent years, tumors have become the second cause of death in patients with transfusion-dependent thalassemia. A lower risk of breast and prostate cancer was observed in the whole group of patients with hemoglobinopathies. The first cancer diagnoses dated back to the 1980s, and the incidence rate sharply increased after the 2000s. However, although the incidence rate of cancers of all sites but the liver continued to show an increasing trend, the incidence of HCC showed stability., Conclusions: These findings provide novel insights into the relationship between cancer and hemoglobinopathies and suggest that the overall risk is not increased in these patients. HCC has been confirmed as the most frequent tumor, but advances in chelation and the drugs that have led to the eradication of hepatitis C may explain the recent steadiness in the number of diagnoses that is reported here., (© 2022 The Authors. Cancer published by Wiley Periodicals LLC on behalf of American Cancer Society.)

There is a paucity of literature on the association of α + -thalassemia, sickle-cell hemoglobin disorders, and malaria in India. This study aimed to understand the effect of α + -thalassemia on the severity of Plasmodium falciparum malaria in adults with respect to sickle-cell genotypes. The study subjects were categorized into 'severe-malaria' and 'uncomplicated-malaria' and age-gender matched 'control' groups. Sickle-cell and α + -thalassemia were investigated in all the recruited subjects. The effect of α + -thalassemia on the severity of malaria was analyzed in HbAA and sickle-cell genotypes (HbAS and HbSS) separately. The prevalence of α + -thalassemia in various groups ranged from 41.5% to 81.8%. The prevalence of α + -thalassemia was lower (OR = 1.64; p =  0.0013) in severe malaria (41.5%) as compared to healthy controls (53.8%) with HbAA genotype. In contrast, in HbAS genotype, the prevalence of α + -thalassemia was higher (OR = 4.11; p =  0.0002) in severe malaria (81.8%) compared to controls (52.2%). In severe malaria with HbAA genotype, there was a significantly higher hemoglobin level and low MCV and MCH level in patients with α + -thalassemia compared to the normal α-globin genotype. Further, the incidence of cerebral malaria, hepatopathy, and mortality was lower in patients (HbAA) with α + -thalassemia as compared to normal α-globin genotype (HbAA). In severe malaria with either HbAS or HbSS genotype, only a few parameters showed statistical differences with respect to α + -thalassemia. Low prevalence of α + -thalassemia in severe malaria with HbAA genotype compared to healthy controls with HbAA genotype indicates the protective effect of α + -thalassemia against severe malaria. However, the high prevalence of α + -thalassemia in patients with HbAS genotype depicts its interference in the protective effect of sickle-cell against severe malaria.

Objective: Thalassemia is a monogenic genetic disorder with a high prevalence in populations in the southern region of China. The thalassemia gene prevalence rate in the Baise population in China is high, and several rare gene variants have been detected in the population of this region during routine testing by our study group. To accurately reveal the thalassemia gene variants carried by the population in Baise, and to provide a basis for the formulation of thalassemia prevention and control policies in the region, we conducted a more comprehensive study in a randomly selected population., Results: In all, 4,800 randomized individuals were recruited for testing from Baise, and the detection of hot spot thalassemia genetic variants were performed by Gap-PCR and PCR-RDB methods, combined with the relative quantification of homologous fragments and AS-PCR to expand the detection range. The prevalence of thalassemia variants in this population was 24.19%, among which 16.69% of individuals carried α-thalassemia gene variants alone, 5.62% carried β-thalassemia gene variants alone, and 1.88% carried both variants., Conclusions: The use of positive primary screening combined with hot spot gene variant detection alone can result in a certain degree of missed detection. In the prevention and control of thalassemia in the region, testing institutions need to pay attention to the detection of rare thalassemia gene variants such as ααα anti4.2 , ααα anti3.7 , -α 2.4 , -α 21.9 , β -50 , β -90 , and β IVS-II-5 , to provide more accurate genetic counseling advice to subjects.

Objectives: Thalassemia, the most common global monogenetic disorder, is highly prevalent in southern China. Epidemiological and molecular characterization of thalassemia is important for designing appropriate prevention strategies in high-risk areas, especially the border area of Guangxi-Yunnan-Guizhou province in southwestern China. Methods: We recruited 38812 reproductive age couples and screened them for thalassemia. Routine blood tests as well as hemoglobin components and levels were evaluated. In addition, suspected thalassemia were identified by gap polymerase chain reaction (Gap-PCR) and PCR-based reverse dot blot (PCR-RDB). Results: The overall prevalence of thalassemia was 26.76%. Specifically, incidences of α-thalassemia, β-thalassemia, and concurrent α- and β-thalassemia were 17.52%, 6.92%, and 2.32%, respectively. The diagnosed α-thalassemia anomalies were associated with six gene mutations and 25 genotypes. The β-thalassemia anomalies were associated with 12 gene mutations and 15 genotypes. Moreover, among the 1799 concurrent mutated α- and β-thalassemia genes, 95 different genotypes were identified. Couples in which both partners were positive for α-thalassemia and β-thalassemia isotypes were 8.80% and 2.08%, respectively. The proportion of couples at a risk of having children with thalassemia major or intermedia was high. Conclusions: This study elucidates on the prevalence and molecular characterization of thalassemia in the border area of Guangxi-Yunnan-Guizhou provinces. These findings provide valuable baseline data for genetic counseling and prenatal diagnosis, with the overarching goal of preventing and controlling severe thalassemia.

Objectives: To explore the application of third-generation sequencing (TGS) for genetic diagnosis and prenatal genetic screening of thalassemia genes., Methods: Two groups of subjects were enrolled in this study. The first group included 176 subjects with positive hematological phenotypes for thalassemia. Thalassemia-associated genes were detected simultaneously in each sample using both the PacBio TGS platform based on single-molecule real-time (SMRT) technology and the conventional PCR-reverse dot blot (PCR-RDB). Sanger sequencing was used for validation when results were discordant between the two methods. The second group included 53 couples with at least one partner having a positive thalassemia hematological phenotype, and they were screened for homotypic thalassemia variants by TGS, and the risk of pregnancies with babies presenting with severe thalassemia, was assessed., Results: Of the 176 subjects, 175 had concordant genotypes between the two methods, including 63 normal subjects and 112 α- and/or β-thalassemia gene carriers, with a concordance rate of 99.43%. TGS detected a rare β-thalassemia gene variant -50 (G > A) that was not detected by conventional PCR-RDB. TGS identified seven of the 53 couples as homotypic thalassemia gene carriers, five of whom were at risk of pregnancies with severe thalassemia., Conclusion: TGS could effectively detect common and rare thalassemia variants with high accuracy and efficiency. This approach would be suitable for prenatal thalassemia genetic screening in areas with high incidence of thalassemia.

Background: Haemoglobinopathies and G6PD deficiency are inherited disorders found mostly in malaria-endemic areas among different tribal groups of India. However, epidemiological data specific to Particularly Vulnerable Tribal Groups (PVTGs), important for planning and implementing malaria programmes, is limited. Therefore, the present community-based study aimed to assess the prevalence of haemoglobinopathies and G6PD deficiency among the 13 PVTGs found in the state of Odisha, reporting the maximum malaria cases in the country., Methods: This cross-sectional study was conducted from July 2018 to February 2019 in 12 districts, home to all 13 PVTGs, in an estimated sample size of 1461, selected two-stage sampling method. Detection of haemoglobinopathies was done by the variant analyser. Screening of G6PD deficiency was carried out using DPIP method followed by quantification using spectrophotometry. The PCR-RFLP technology was used to determine variant of G6PD deficiency and haplotype analysis of sickle cell, while ARMS-PCR and GAP-PCR was used for detecting the mutation pattern in β-thalassaemia and α-thalassaemia respectively. The diagnosis of malaria was done by Pf-PAN RDT as point of care, followed by nPCR for confirmation and Plasmodium species identification., Results: The prevalence of sickle cell heterozygotes (AS) was 3.4%, sickle cell homozygous (SS) 0.1%, β-thalassaemia heterozygotes 0.3%, HbS/β-thalassaemia compound heterozygote 0.07%, HbS-α-thalassaemia 2.1%, G6PD deficiency 3.2% and malaria 8.1%. Molecular characterization of β S revealed the presence of Arab-Indian haplotype in all HbS cases and IVS 1-5 G → C mutation in all β-thalassaemia cases. In case of α-thal, αα/α-3.7 gene deletion was most frequent (38%), followed by αα/α-4.2 (18%) and α-3.7/α-3.7 (4%). The frequency of G6PD Orissa (131C → G) mutation was found to be 97.9% and G6PD Mediterranean (563C → T) 2.1%. Around 57.4% of G6PD deficient individuals and 16% of the AS were found to be malaria positive., Conclusion: The present study reveals wide spread prevalence of sickle cell anaemia, α-thalassaemia, G6PD deficiency and malaria in the studied population. Moderate to high prevalence of G6PD deficiency and malaria warrants G6PD testing before treating with primaquine (PQ) for radical cure of Plasmodium vivax. Screening and counselling for HbS is required for the PVTGs of Odisha., (© 2022. The Author(s).)

Despite the fact that most hemoglobin (Hb) variants are clinically and hematologically silent, they can interact with thalassemias, which could sometimes give rise to complicated routine thalassemia diagnostics. Hb G-Siriraj [β7(A4)Glu→Lys; HBB : c.22G>A] alone is a benign condition, but its coinheritance with α-thalassemia (α-thal) may lead to misdiagnosis. We describe the case of a Chinese woman with an elevated Hb A 2 level who was assumed to carry heterozygous β-thalassemia (β-thal), but was later shown to be a double heterozygote for Hb G-Siriraj and Hb H disease. This study for the first time described hematological characteristics of a patient with a double heterozygosity for Hb G-Siriraj and Hb H disease. It is of great significance for technicians and clinicians to expand their knowledge as well as to help guide clinical diagnosis, population screening and genetic counseling.

Background: There is a high carrying rate of α-thalassemia in Fujian province. However, there are few large-scale studies on the correlation between genotype and phenotype in Fujian province. The purpose of this study was to analyze the phenotype and genotype in a cohort of 2923 patients with α-thalassemia in Fujian province, so as to provide reference data for screening and diagnosis of α-thalassemia in Fujian province., Methods: The genotype of α-thalassemia was detected by PCR reverse dot blot assay, gap-PCR, single PCR, nested PCR, and sequencing. Clinical and hematological indices of 2923 patients were collected, and the correlation between genotype and phenotype was analyzed., Results: Among 10,350 patients, 2923 cases were found with α-thalassemia, with a detection rate of 28.24%. Among them, -- SEA /αα was the most common genotype, accounting for 64.80%. In addition, rare α-thalassemia genotypes were detected in Fujian province, including -- THAI /αα (0.41%), HKαα/-- SEA (0.03%), and the novel α-thalassemia gene mutation CD5 (GCC>ACC) (HGVS named HBA1: c.16G>A) (0.03%). Patients with deletional genotypes of α-thalassemia were found to have higher RBC and lower Hb, MCV, MCH, and HbA2 than patients with non-deletional genotypes of α-thalassemia (p < 0.05)., Conclusion: The clinical phenotype of α-thalassemia is influenced by molecular mechanisms. HBA1: c.16G>A mutation is a novel mutation that was first reported in Fujian province, which enriches the human hemoglobin mutation spectrum., (© 2022 The Authors. Journal of Clinical Laboratory Analysis published by Wiley Periodicals LLC.)

Objective: To investigate gene mutation types of thalassemia in the population of this area and the relationship between hematological phenotype and age in β-thalassemia., Methods: 1 351 suspected cases of thalassemia were detected in the First Affiliated Hospital of Chengdu Medical College from June 2017 to June 2021. PCR-reverse dot blot hybridization(PCR-RDB) technique was used to detect the common α and β thalassemia gene types, then the data of MCV, MCH, MCHC and Hb of confirmed cases were collected. The heterozygotes of β-thalassemia were divided into 0-18 year group, 19-50 year group and >50 year group according to age, and the differences of hematological phenotypes among different groups were compared., Results: Among the detected 1 351 samples， 523(38.71%) cases were diagnosed as thalassemia, 13 genotypes were detected in 260 cases (19.25%) with α-thalassemia; and 12 genotypes were detected in 252 cases (18.65%) with β-thalassemia; 9 genotypes were detected in 11 cases with αβ thalassemia. It was found that MCV and MCH were increased significantly in 0-18 year group, 19-50 year group and >50 year group, MCHC was highest in 0-18 year group, and Hb was the lowest in the >50 year group, and the difference was statistically significant（P<0.05）., Conclusion: In this area, -- SEA /αα was the major genotype of α-thalassemia, and CD41-42 /N and IVS-II-654/N were the major genotypes of β-thalassemia. Morever, MCV and MCH were the lowest in the 0-18 year old group and the highest in the >50 years old group in heterozygotes of β-thalassemia. The influence of age on hematological parameters in the primary screening of thalassemia provides a certain reference value in clinical diagnosis and treatment.

Hemoglobin H (Hb H) disease is a subtype of α-thalassemia caused by deletional and/or non-deletional mutations in three alpha-globin genes in which the various genotypes determine the disease severity. This study was aimed to investigate the frequency of alpha gene mutations and genotypes and their correlation with hematological and clinical characteristics in Iran. Among 202 patients diagnosed with Hb H disease through a national study in Iran according to standard methods, we had access to the hematologic and clinical findings and genetic data of 101 patients in whom genetic study was performed. Genomic DNA from peripheral blood was extracted and analyzed for identification of α-globin gene mutations using Multiplex Gap Polymerase Chain Reaction, Reverse Hybridization Assay, and finally Direct DNA Sequencing method. Twenty-one different mutations and thirty genotypes were detected in 101 patients with Hb H disease. In total, 39 patients (38.6%) were deletional and 62 patients (61.4%) were non-deletional type of the disease. The -- MED mutation was highly prevalent in almost half of the patients (56.4%). Among various genotypes, - MED /-a 3.7 (29.7%) and -α 20 .5 /-α 5NT (6.9%) were the most prevalent genotypes found in the studied group. Patients with non-deletional type presented with more severe hematological and clinical findings. Hb H percentage and serum ferritin levels were significantly higher in non-deletional patients in comparison to the deletional group ( p  < 0.05). 12 (11.9%) and 40 (39.6%) out of 101 patients were on regular and occasional transfusions, respectively. 83% of those with regular transfusion belonged to the non-deletional group. Among transfusion-dependent patients, - MED /α CS α and α 20 .5 /-α 5NT were the most common genotypes. In this study, two patients with -α 20 .5 /α CS α and - MED /α -5NT genotypes experienced thrombotic events. This study indicated that although non-deletional genotypes of Hb H disease were responsible for more clinical severity of the disease, due to the presence of severe phenotypes even in deletional types, no definite correlation was found between genotype and phenotype.

Thalassemia is one of southern China's most common inherited disorders. Little is known about the genotypes of thalassemia in children in Jiangxi Province, the People's Republic of China (PRC). Two thousand, nine hundred and fifty-two children with suspected thalassemia were recruited from August 2016 to December 2020 at the Jiangxi Provincial Children's Hospital, Nanchang, PRC. Reverse dot-blot hybridization was used to detect α- and β-thalassemia (α- and β-thal) genotypes. A rare mutation was detected using gap-polymerase chain reaction (gap-PCR) and gene sequencing. The overall distribution of thalassemia (1534 cases) was 51.96%, and the detection rate of α-thal (616 cases), β-thal (888 cases) and concurrent α- and β-thalassemias (30 cases) was 20.86, 30.08, and 1.02%, respectively. A rare α-thal genotype, -α 27.6 /- - SEA (Southeast Asian), was identified. Seventy-eight cases of severe β-thal were detected, accounting for 8.78% of the cases, including 56 double heterozygous cases and 22 cases that were homozygous. Both α- and β-thalassemias are widely distributed in the children of Jiangxi Province. Thalassemia genetic testing is essential to establish a comprehensive thalassemia prevention program and improve public education.

Vietnam has a high thalassemia burden. We collected blood samples from 5880 pregnant Vietnamese women during prenatal health checks to assess thalassemia carrier frequency using combined gap-polymerase chain reaction (gap-PCR) and targeted next-generation sequencing (NGS). Thalassemia carriers were identified with prevalence of 13.13% (772), including 7.82% (460) carriers of α-thalassemia (α-thal), 5.31% (312) carriers of β-thalassemia (β-thal), and 0.63% (37) concurrent α-/β-thal carriers. Deletional mutations (368) accounted for 80.0% of α-thal carriers, of which, -- SEA (Southeast Asian) ( n  = 254; 55.0%) was most prevalent, followed by the -α 3.7 (rightward) ( n  = 66; 14.0%) and -α 4.2 (leftward) ( n  = 45; 9.8%) deletions. Hb Westmead ( HBA2 : c.369C>G) ( n  = 53) and Hb Constant Spring (Hb CS or HBA2 : c.427T>C) (in 28) are the two most common nondeletional α-globin variants, accounting for 11.5 and 6.0% of α-thal carriers. We detected 11 different β-thal genotypes. Hb E ( HBB : c.79G>A) (in 211) accounted for 67.6% of β-thal carriers. The most common β-thal genotypes were associated with mutations at codon 17 (A>T) ( HBB : c.52A>T), codons 41/42 (-TTCT) ( HBB : c.126&#95;129delCTTT), and codon 71/72 (+A) ( HBB : c.217&#95;218insA) (prevalence 0.70%, 0.68%, and 0.2%, respectively). Based on mutation frequencies calculated in this study, estimates of 5021 babies in Vietnam are affected with clinically severe thalassemia annually. Our data suggest a higher thalassemia carrier frequency in Vietnam than previously reported. We established that combining NGS with gap-PCR creates an effective large-scale thalassemia screening method that can detect a broad range of mutations.

The prevalence of alpha-thalassemia as a major health problem in the south of Iraq has highlighted the necessity of investigations and screening of patients with thalassemia. The present study aimed to characterize the spectrum of alpha-globin gene mutations in patients who were followed up in a genetic diseases center in Thi-Qar province. A total of 30 subjects were collected from thalassemia patients and 15 cases as the control group. Polymerase chain reaction (PCR) and direct sequencing were performed for functionally regions of the gene (exon 1 and exon 2). The fragment size amplified was 442 bp in the Exon 1 region and 324 bp in the Exon 2 region of α-globin. The molecular analysis of the sequence of PCR products revealed that 13 point mutation within the α-thalassemia gene included deletion and substitution mutation, while the rest of the mutations were in the intron site of the gene. These results indicated that mutations may constitute a risk of developing hemophilia B disease. Molecular mechanisms in the expression of globin genes are used to help manage patients with thalassemia.

Thalassemia is a group of common hereditary anemias that cause significant morbidity and mortality worldwide. However, precisely diagnosing thalassemia, especially rare thalassemia variants, is still challenging. Long-range PCR and long-molecule sequencing on the PacBio Sequel II platform utilized in this study could cover the entire HBA1, HBA2 and HBB genes, enabling the diagnosis of most of the common and rare types of thalassemia variants. In this study, 100 cases of suspected thalassemia were subjected to traditional thalassemia testing and third-generation sequencing for thalassemia genetic diagnosis. Compared with traditional diagnostic methods, an additional 10 cases of rare clinically significant variants, including 3 cases of structure variants and 7 cases of single nucleotide variations (SNVs) were identified, of which a case with - α 3.7 subtype III (- α 3.7III ) was first identified and validated in the Chinese population. Other rare variants of 11.1 kb deletions (- 11.1/αα), triplicate α-globin genes (aaa 3.7 /αα) and rare SNVs have also been thoroughly detected. The results showed that rare thalassemia variants are not rare but have been misdiagnosed by conventional methods. The results further validated third-generation sequencing as a promising method for rare thalassemia genetic testing., (© 2022. The Author(s).)

Despite several studies performed in different provinces of Iran to identify the spectrum of α-globin gene mutations, no such study has so far been carried out in Ilam Province. A total of 274 individuals, including 201 α-thalassemia (α-thal) carriers and 73 normal subjects, originating from the northern counties of Ilam Province, participated in this study. Analysis of α-globin defects was performed using multiplex gap-polymerase chain reaction (gap-PCR), amplification refractory mutation system (ARMS)-PCR and direct sequencing, which revealed a total of 11 different mutations and 22 different genotypes. The -α 3.7 (rightward) (NG&#95;000006.1: g.34164&#95;37967del3804), α -5 nt α ( HBA2 : c.95 + 2&#95;95 + 6delTGAGG), and -α 4.2 (leftward) deletions were the most prevalent mutations identified in our study, with frequencies of 66.23, 10.09 and 8.33%, respectively. In conclusion, the present study showed that the α-thal mutation spectrum in Ilam Province, at least in the northern part of the province, is different from that in other geographical regions of Iran. These results increase our knowledge about the spectrum and distribution of α-globin gene mutations in Iran.

Objective: To analyze the genotype characteristics of α- and β-thalassemia and the diagnostic value of hematological indexes in pregnant women in Xindu District of Chengdu., Methods: The blood routine parameters(MCV) <80 fl and (or) (MCH) <27 pg and hemoglobin electrophoresis were used to screen the pregnant women, PCR-reverse dot blot hybridization(PCR-RDB) technique was used to detect the common α- and β-thalassemia gene types in the primary screening positive population. The husbands of the diagnosed pregnant women were recalled for gene testing, and the highly suspected patients were checked by gene sequencing., Results: Among the 7 049 pregnant women, 1 740(24.68%) cases were positive for primary screening. 180 patients were diagnosed as thalassemia gene positive, among them, 94 cases (52.22%) of α-thalassemia were detected and six genotypes were found, in which -- SEA /αα genotype was the highest (58 cases, 61.70%); 82 cases (45.56%) of β-thalassemia were detected and ten genotypes were found while CD41-42/N and CD17/N genotypes were the most common; there were 4 cases(2.22%) with α combined with β-thalassemia. Through clinical follow-up survey, there were 4 couples with the same type of thalassemia, one of them was induced labor after diagnosis of hemoglobin H disease. Receiver operating curve (ROC curve) was used to analyze the diagnostic value of hematological parameters in thalassemia positive pregnant women. The results showed that AUC(HBA 2 )SEA /αα, CD41-42/N, CD17/N. The blood routine indicators (HBA 2 、RDW-SD、MCHC、MCH、MCV) have high diagnostic value for screening of thalassemia.

We studied the alpha-globin gene genotypes, hematologic values, and transfusion-dependence of patients with Hb H disease. Molecular characterization of alpha-thalassemia was performed. We identified 120 patients with Hb H disease. Of these patients, 35 (29.16%) had deletional form of Hb H disease, and 85 (70.83%) had different form of non-deletional Hb H disease. The most frequently observed Hb H genotypes were -- Med /-α 3.7 in 33 patients (27.5%), α CD19(-G) α /αCD19(-G) α in 25 cases (20.83%), α polyA2 α/α polyA2 α in 15 (12.5%), and α polyA1 α/α polyA1 α in 13 (10.83%) respectively. The probability of receiving at least one transfusion blood in deletional form was observed in 3 of 35 (8.57%) patients which just seen in 3 of 33 (9%) patients with -- Med /-α 3.7 genotype. This form was also observed in 8 of 85 (9.4%) patients in non-deletional Hb H diseases which five of them had Med deletion in compound with alpha globin point mutations. Nondeletional Hb H disease was more severe than deletional Hb H disease requiring more blood transfusions. We can recommend that Med deletion in compound with alpha-globin point mutations, polyA1 and constant spring in homozygous form needs to be taken into consideration when offering counseling to high-risk couples., (© 2022. The Author(s).)

Objective: To present the result of newborn sickle cell disease (SCD) screening and clinical profile of SCD newborns in a tribal area of Gujarat., Methods: We screened all newborns of sickle cell trait (SCT) and SCD mothers for SCD using high-performance liquid chromatography (HPLC) within two days of birth at a secondary care hospital in a tribal area in Gujarat from 2014 to 2019. Newborns with SCD were registered under an information technology based platform for hospital-based comprehensive care. Neonates were followed prospectively every 3 months. If they missed the clinic visit, a medical counsellor visited them at home to collect the required information., Results: Out of 2492 newborns screened, 87 (3.5%) were diagnosed with SCD. Among the 67 newborns screened for alpha-thalassemia deletion, 64 (95.4%) of babies had alpha-thalassemia deletion. We recorded total 554 clinic visits over the period of 221.5 person-years. The rates of acute febrile illness, painful crisis, hospitalization and severe anemia were 42.9, 14.9, 14.9 and 4.5 per 100 person-year, respectively. Two deaths were recorded, and 5 babies (5.7%) had severe SCD., Conclusion: We found a high prevalence of alpha thalassemia deletion among newborn SCD cohort in tribal area of Gujarat, and 70% babies had atleast one clinical complication on follow-up.

Abstract: There is no information concerning the prevalence of thalassemia among pregnant women in Hubei Province currently. This study is aimed to explore the prevalence of α- and β-thalassemia genotypes among pregnant women in Hubei Province, and to explore the clinically applicable screening approach, as well as to investigate the pregnancy outcomes of α- and β-thalassemia carriers.Pregnant participants were recruited from 4 hospitals for the screening of α- and β-thalassemia mutations in Hubei Province. Polymerase Chain Reaction and flow cytometry methods were used to examine α- and β-thalassemia mutations. The hematological parameters and pregnancy outcomes of α- and β-thalassemia carriers were obtained from the hospital information system. The chi-square tests were used to evaluate the difference in hematological parameters between pregnant thalassemia carriers and the control group.Among 11,875 participants, 414 (3.49%) were confirmed with α-thalassemia carriers, 228 (1.92%) were confirmed with β-thalassemia carriers, and 3 (0.03%) were confirmed with both α- and β-thalassemia carriers. The frequency of -α3.7 accounted for 2.05% and it was the most frequent genotype of α-thalassemia; the proportion of IVS-II-654 was 0.85% and it was the most frequent genotype of β-thalassemia in Hubei Province. Furthermore, the proportion of patients with low mean corpuscular volume (MCV) or mean cell hemoglobin (MCH) values was accounted for 36.64% and 93.97% among α-thalassemia and β-thalassemia carriers, respectively. And participants with normal MCV and MCH values were accounted for 95.07% among non-thalassemia participants. High prevalence of pregnancy-induced diabetes (16.97%), preterm birth (9.96%), pregnancy-induced hypertension (8.12%), and low birth weight (5.90%) were observed among pregnant thalassemia carriers.MCV and MCH values were suggested to apply on the preliminary screening of pregnant β-thalassemia; however, it's unpractical on that of α-thalassemia. Furthermore, thalassemia carriers might have a high risk of negative pregnancy outcomes. These findings could be useful for the preliminary screening of thalassemia and perinatal care for the pregnant thalassemia carriers., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2022 the Author(s). Published by Wolters Kluwer Health, Inc.)

Background: Hainan has one of the high incidences of thalassemia in China, but the epidemiological data in the whole province has not been reported yet. The objective of our study was to reveal the true prevalence and molecular mutation spectrum of thalassemia in the population of Hainan who are of childbearing age., Methods: We screened 166,936 individuals from 19 cities and counties in Hainan by hematological parameters analysis, and further conducted genetic analysis for individuals whose MCV was less than 82fL., Results: In total, 21,619 (12.95%) subjects were diagnosed as thalassemia carriers or patients. The overall prevalence of α-thalassemia, β-thalassemia, and α+β-thalassemia were 10.39%, 1.38%, and 1.18%, respectively. Eleven α-thalassemia mutations and sixteen β-thalassemia mutations were identified. The high-frequent genotypes of α-thalassemia were -α 3.7 /αα (19.70%), -α 4.2 /αα (19.39%), αα/-- SEA (15.60%), α WS α/αα (9.24%), and -α 3.7 /-α 4.2 (8.90%), and those of β-thalassemia were β CD41/42(-TTCT) /β N (58.92%), β -28(A>G) /β N (16.05%), β IVS-Ⅱ-654(C>T) /β N (8.42%), β CD71/72(+A) /β N (6.03%), β CD17(A>T) /β N (5.47%), and β CD26 (GAG>AAG) /β N (2.69%). In addition, the frequencies and hematological profiles of many rare mutations of α- [Fusion, HKαα, αααanti 4.2 , IVS-II-55 (T>G), IVS-II-119 (-G,+CTCGGCCC)] and β-globin genes [-50 (G>A), IVS-Ⅱ-81 (C>T)] in Hainan were reported for the first time., Conclusion: Our study revealed the high prevalence and extensive molecular spectrum of thalassemia in childbearing age population of Hainan, suggesting thalassemia in Hainan ranks second in prevalence among all regions in China. The findings will be useful for genetic counseling and prevention of thalassemia., (© 2022 The Authors. Journal of Clinical Laboratory Analysis published by Wiley Periodicals LLC.)

Objective: To study the distribution characteristics of thalassemia genotype in Han Population in Sanya of Hainan Province., Methods: Gap PCR and reverse dot hybridization were used to detect and analyze the thalassemia gene in 572 suspected thalassemia carriers of Han Population in Sanya., Results: Among the 572 Han Population in Sanya, 271 cases of thalassemia gene abnormality were detected, among which 161 cases were founded to be carriers of α-thalassemia gene. A total of 9 genotypes were detected, in the following order of the detection rate was －－ SEA /αα，－α 3.7 /αα，－α 4.2 /αα，－－ SEA /－α 3.7 ，－－ SEA /－α 4.2 ，－α 4.2 /－α 4.2 ，－α 3.7 /－α 4.2 ，－α 3.7 /－α 3.7 ，－－ SEA /－－ SEA . Among them, the deletion type (－－ SEA /αα) in southeast Asia was the most common, accounting for 66 cases. 99 cases of β-thalassemia were detected, there were 7 genotypes, all of which were heterozygous. The order of the detection rate was CD41-42/βN, IVS-II-654/βN, CD17/βN, CD71-72/βN, -28/βN, －29/βN, CD27-28/βN. Among them, CD41-42/βN was the most common, accounting for 51 cases. In addition, 11 cases of combined α and β thalassemia were detected. Five kinds of genotypes were checked out, the order of detection rate was －α 3.7 /αα composite CD41-42/βN, －－ SEA /αα composite IVS-II-654/βN, －α 4.2 /－α 4.2 composite CD41-42/βN, －α 4.2 /αα composite －29/βN , －－ SEA / －α 4.2 composite CD41-42/βN., Conclusion: Han Population in Sanya of Hainan Province is a high-risk population of thalassemia, the genotype characteristics are different from other areas with high incidence of thalassemia in China. The main type of α-thalassemia is the deficiency mutation of southeast Asia, while CD41-42 heterozygous mutation is the main type of β-thalassemia.

Introduction: The hematological and clinical features vary markedly between the different genotypes of sickle cell disease. Even within the single genotype of homozygous sickle cell disease (HbSS), there is marked variability that is presumed to result from interacting genetic and environmental factors., Areas Covered: The classification of the different genotypes of sickle cell disease with approximate prevalence at birth in different communities and some of the major clinical and hematological differences. This assessment includes three potential genetic factors influencing hematology and clinical outcome in HbSS, the beta globin haplotype, alpha thalassemia, and persistence of fetal hemoglobin (HbF)., Expert Opinion: The author is a clinician with experience of sickle cell disease primarily in Jamaica but also in Greece, Uganda, Saudi Arabia, and India. It is therefore necessarily an account of clinical data and does not address current debates on molecular mechanisms. Most data derive from Jamaica where efforts have been made to reduce any symptomatic bias by long-term follow-up of patients all over the Island and further reduced by a cohort study based on newborn screening, which has been in operation for over 48 years.

The population of Viet Nam, is 96.2 million, of which 13.8% are carriers of thalassemia genes. Thalassemia/hemoglobinopathies carriers exist at different frequencies in all 54 ethnic groups of the country. Gene carrier rate and globin gene mutation rate varies ethnically and topographically. The ethnic groups in the Northern Highland region have high rates of α 0 - and β 0 -thalassemia (α 0 - and β 0 -thal), while those in the Southern Middle region have high rates of α + -thalassemia (α + -thal) and Hb E (or codon 26) ( HBB : c.79G>A). The lowest is found in La Hu (0.23%), while the highest is found in Raglai (88.6%). Thalassemia prevention and control programs were introduced using prenatal and neonatal diagnosis for the prevention of new thalassemic births. Most existing thalassemia patients are undergoing supportive treatment with regular blood transfusions and iron chelation. Curative treatment by hematopoietic stem cell transplantation is available but is limited to a minority of the patients.