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Objectives: We analyzed hemoglobin (Hb) levels and degree of anemia in relation to genotype in patients with hemoglobin H (Hb H) disease, thereby providing a scientific basis for the prevention and treatment of Hb H disease in the Guangxi region of China., Methods: Hb analysis was conducted in 615 patients using high performance liquid chromatography. Seven α-thalassemia and 17 β-thalassemia genotypes commonly found in the Chinese population were detected by Gap-polymerase chain reaction and reverse dot hybridization. Multiple ligation-dependent probe amplification and sequencing were used to detect α-globin gene., Results: On analyzing the degree of anemia, we found that the proportion of severe and moderate anemia was the highest among cases with - SEA /α CS α genotype, followed by - SEA /α QS α. When Hb H disease was present in combination with β-thalassemia, the clinical symptoms of most patients were milder than those with simple Hb H disease., Conclusion: The clinical manifestations of various types of Hb H disease are heterogeneous; the Hb levels of patients with deletional Hb H are generally higher than those with non-deletional Hb H ( P < 0.05). In-depth knowledge of the gene mutation spectrum of thalassemia in Guangxi can provide a basis for genetic counseling of couples and enable prenatal diagnosis.

Hb Constant Spring (Hb CS; HBA2: c.427T > C) is an unstable hemoglobin (Hb) variant that results from a nucleotide substitution at the termination codon of the α2-globin gene. Compound heterozygosity for α(0)-thalassemia (α(0)-thal) and Hb CS (- -(SEA)/α(CS)α) results in Hb H/Hb CS disease, which is generally characterized with mild hemolytic anemia, jaundice, and splenomegaly. Here, we describe one case with Hb H/Hb CS disease that presented with fetal anemia and fetal hydrops, known as Hb H (β4) hydrops fetalis. This is the first report of fetal hydrops caused by association of the - -(SEA) deletion and the α(CS)α mutation. Our study highlights the significance of watchful observation using a serial ultrasound method and care of pregnant women who have fetuses found to carry Hb H/Hb CS disease during pregnancy, to guard against the occurrence of fetal hydrops.

Hb H (β4) disease is an inherited hemoglobin (Hb) defect in which three of the four α-globin genes are deleted or dysfunctional. The clinical manifestations vary widely from mild asymptomatic anemia to a severely anemic state. Recent literature suggests that Hb H disease is not as benign a disorder as previously thought. Newborn screening for Hb H disease is especially appealing because the screening test is based on the detection of Hb Bart's (γ4) that is only possible within the newborn period. In a 2-year period of newborn screening, 18 babies were found to have Hb H disease in a total of 9490 newborns. The overall prevalence for Hb H disease among all newborns in southern China is approximately 1 in 500. The correct diagnosis would allow affected infants to be properly cared for and reduce mortality rate.

Abstract We report the genetic data of 435 patients with Hb H (β4) disease who presented at our center between 2005 and 2012. Our results showed that all patients had the Southeast Asian deletion (- -(SEA)) on one allele. The -α(3.7) (rightward) deletion was the most common on the other allele, followed by the -α(4.2) (leftward) deletion, Hb Constant Spring (Hb CS, α142, Term → Gln; HBA2: c.427T  > C) and Hb Quong Sze [Hb QS, α125(H8)Leu → Pro; HBA2: c.377T  > C] mutations. Two rare point mutations, α31(B12)Arg → Lys; HBA2: c.95G > A and Hb Zurich Albisrieden [α59(E8)Gly → Arg; HBA1: c.178G  > C], were also identified. Four patients had a concomitant β-thalassemia (β-thal) heterozygosity. Our results reflect the genetic heterogeneity of Hb H disease and the interaction between Hb H disease and β-thal trait in Southern China.

Objective: To study the characteristics of genotype spectrum and hematologic parameters in children with HbH disease in the North Guangxi region., Methods: HbH disease was identified by clinical manifestations, routine blood tests and hemoglobin electrophoresis in 166 children who came form the North Guangxi region. Genotypes were determined by Multi-PCR combined with PCR reverse dot blot. DNA sequencing was used when the genotype could not be identified by regular methods., Results: Of the 166 children with HbH disease, 8 genotypes were identified: --SEA/-α3.7 (82 cases), --SEA/-α4.2 (40 cases), --SEA/αCSα (38 cases), --SEA/αQSα (1 case), --SEA/αWSα (1 case), --SEA/αCD43/44 (-C) α (1 case), --SEA/-α3.7 plus CD17 (A→T) (1 case) and --SEA/-α4.2 plus CD41-42(-TTCT) (1 case). One case was confirmed as the heterozygote of --SEA and an unknown mutation. In the 134 cases with complete medical data, 2 had normal hemoglobin levels, 36 manifested mild anemia, 90 manifested moderate anemia, and 6 (genotype: --SEA/αCSα) showed severe anemia because of the coexistence of infection. Children with the genotype of --SEA/-α3.7 (69 cases), --SEA/-α4.2 (31 cases) and --SEA/αCSα (34 cases) had hemoglobin levels of 62-120, 69-127 and 34-110 g/L respectively. The hemoglobin level in the --SEA/αCSα group was significantly lower than in the deletional HbH disease group (genotypes: --SEA/-α3.7 and --SEA/-α4.2 ) (P<0.05). In contrast, MCV levels in the --SEA/αCSα group were significantly higher than in the deletional HbH disease group (P<0.05)., Conclusions: The genotype spectrum of HbH disease is diverse in the North Guangxi region. Deletional genotype is prevalent. The disease is heterogeneous. The children with --SEA/αCSα HbH disease have severer anemia and higher MCV levels than those with deletional HbH disease.

Most of recognized alpha-thalassemia mutations include deletions of one or both alpha-globin genes. Here we describe a newly detected alpha-thalassemia-2 deletion characterized by a small 2.8 kb deletion involving the a 2 globin gene. This deletion has thus far been observed in one Chinese subject with hemoglobin H disease. Its breakpoints were detected to lie between coordinates 32485 and 35381 of the alpha-globin gene cluster (NG&#95;000006.1), with a total of 2,894 nucleotides deleted. It was designated as -alpha2.8 deletion. The proband is a compound heterozygote deletion of -SEA and -alpha2.8, and the patient displayed very mild hemoglobin H disease phenotype with hemoglobin 9.8 g/dL.

Hb H (β4) disease is the most common form of thalassemia intermedia. Two main types of Hb H disease, deletional and nondeletional, are characterized. Patients with nondeletional Hb H disease are usually more anemic with organomegaly; some may require regular blood transfusions and even be as severely affected as Hb H hydrops fetalis. However, there is no clear genotype-phenotype correlation associated with this severe clinical syndrome as patients with identical genotypes do not necessarily show the same severity. In this report, we described two nondeletional Hb H-Hb Quong Sze [α125(H8)Leu→Pro, CTG>CCG (α2)] disease individuals in a family who presented with phenotypic variability.

The clinical characteristics of 357 patients with hemoglobin H (HbH) disease from the Guangxi province of Southern China were studied. One hundred and ninety-one (53.3%) patients were diagnosed with HbH-Constant Spring, 19 were diagnosed with HbH Westmead. Ten patients were shown to have coinherited HbH-Constant Spring/QS with a β-thalassemia mutation. Coinheritance of the β-thalassemia gene does not alleviate anemia (8.2 ± 2.3 vs. 7.6 ± 1.7 g/dl, p = 0.276), or influence age at diagnosis (20.2 ± 19.6 vs. 12.9 ± 11.0 years, p = 0.276). Ferritin levels were significantly higher in the group of patients with the nondeletional form of the disease (475 ± 719 vs. 249 ± 264 ng/ml, p = 0.005)., (Copyright © 2010 S. Karger AG, Basel.)

Four Chinese patients with Hb Q-H disease were identified during thalassemia screening. The main hematological characteristics of Hb Q-H disease are that Hb A is absent, and Hb Q-Thailand (also known as G-Taichung, Mahidol, Kurashiki-I and Asabara) accounts for the majority of the total hemoglobin (Hb). The phenotype of this disorder is similar to that of deletional Hb H (beta4) disease.

Hemoglobin H disease (HbH) is a hemoglobinopathy peculiar to parts of the world with high incidence alpha-thalassemia mutations. Among 90 HbH cases, 50 cases suffered from clinically significant jaundice (bilirubin >30 mmol/l), including 14 with severe jaundice (bilirubin >60 mmol/l). Cholelithiasis was found in 38 cases. The incidence is roughly eight times higher than that in background control population but 50% lower than that in beta-thalassemia. The risk of gallstones was related to higher bilirubin levels but not alpha-globin genotype, sex, ferritin, and hemoglobin levels. Homozygotes or double heterozygotes for Gilbert alleles (17.2%), but not heterozgyotes (42.2%), were found to have a significantly increased risk of gallstones and jaundice. However, common Chinese Gilbert syndrome alleles do not completely explain the variable risks.

A simple and an efficient oligonucleotide array was developed to identify common severe determinants of alpha (alpha) thalassemia. A total of 14 probes were designed to detect the most frequently three deletions (-alpha(3.7), -alpha(4.2), -(SEA)) and two non-deletions (alpha(Quong Sze), alpha(Constant Spring)). PCR products were amplified from human genomic DNA and allowed to hybridize with the oligonucleotide array. Hybridization was detected by fluorescence scanning, and alpha globin genotypes were assigned by quantitative analysis of the hybridization results. The efficiency and specificity of identifying alpha globin genotypes using the oligonucleotide arrays was evaluated by blinded analysis of 690 samples from unrelated individuals. The oligonucleotide array method described in this paper provides unambiguous detection of complex combinations of heterozygous, compound heterozygous and homozygous alpha thalassemia genotypes. The experimental results demonstrate that this methodological approach may be applied for screening and for hemological diagnosis in population at large.

Objective: To analyze genotypic profiles and understand the relationship between the genotype and phenotype of Hb H disease in Guangxi province., Methods: Hematologic and Hb analyses on the cases were performed to detect their alpha thalassemia genotypes using PCR method and DNA sequencing., Results: An unusual case was identified in one of the 298 patients with Hb H disease diagnosed in the First Affiliated Hospital of Guangxi Medical University from October 2002 to November 2003. The 25-year-old male patient, a native of Yulin in Guangxi province, had had jaundice and splenomegaly since childhood, and he had never received blood transfusion. Hematologic examinations revealed his hemoglobin 107 g/L, RBC 4.9+10(12) g/L, MCV 76.2 fl, MCH 21.8 pg, MCHC 287 g/L, HCT 0.373, reticulocyte 3%. Hb analysis showed the level of Hb H + Hb Bart's 34.41%. PCR and DNA sequencing confirmed the genotype of a deletion at codon 30 of alpha2 globin gene and SEA alpha-thalassemia-1., Conclusion: This unusual case had no anemia, but had higher level of Hb H and Hb Bart's when compared to those non-deletional Hb H disease cases such as Hb CS-H, HbQS-H and alpha2 codon 31 mutation combined with SEA alpha-thalassemia-1 previously reported in mainland China. The discovery and recognition of this gene mutation and related genotype and phenotype is of importance to the genetic counseling and prenatal diagnosis in Guangxi province where the incidence of alphathalassemia is very high.

Objective: Alpha-thalassemia is one of the most common monogene disorders in the world. Most frequently, it is caused by deletions of alpha-globin gene (-alpha or --), and less commonly resulted from the non-deletional mutation (alpha(T)alpha). Hemoglobin H (HbH) disease is the most severe type among survivors of alpha-thalassemia. The clinical presentation of children with the disease was highly heterogeneous. The aim of this study was to investigate the effect of alpha-globin genotypes in the children with HbH disease on predicting the phenotypic severity and to define the factors involved in the disease progress., Methods: Forty-three children with the disease in Zhuhai area of Guangdong, China were examined by using established techniques to detect genotypes of alpha-globin and to determine all hematological parameters. All detailed clinical data of the cases were recorded. Then clinical and hematological findings, and the correlation with genotypes were evaluated., Results: Six alpha-thalassemia mutations were detected and interacted to produce 5 HbH disease genotypes. Of these genotypes, -alpha(3.7)/--(SEA)(60%), -alpha(4.2)/--(SEA) (19%) and alpha(CS)alpha/--(SEA) (12%) HbH diseases were prevalent in the area. Compared with -alpha(3.7)/--(SEA) HbH disease, significantly lower red blood cell (RBC) count, hemoglobin (Hb), mean corpuscular hemoglobin (MCHC) and HbA(2) (P < 0.05, 0.01, 0.01 and 0.01, respectively), and significantly higher mean corpuscular hemoglobin volume (MCV) and HbH levels (both P < 0.01), and more severe clinical phenotypes were found in the HbH disease with alpha(T)alpha/--(SEA) genotype. While the differences were much more significant when compared with -alpha(3.7)/--(SEA) then compared with -alpha(4.2)/--(SEA) not only in the hematological parameters, but also in the severity of clinical phenotypes. In addition, HbH levels showed anegatively correlation with the RBC count (r = -0.39, P < 0.01)., Conclusion: The phenotypes of HbH disease may be mainly related to the underlying genotypes. The children with alpha(T)alpha/--(SEA) genotype presented with more severe hematological and clinical phenotypes followed by the -alpha(4.2)/--(SEA) and then -alpha(3.7)/--(SEA) genotypes. But phenotypic severity was not simply related to the degree of alpha-globin deficiency. HbH levels were found to exacerbate anemia. These data might provide comprehensive and very valuable and basic information for the management of HbH disease, genetic counseling and prenatal diagnosis.

There is a high prevalence of thalassemia in the South of China. To explore the genotype of alpha-thalassemia as well as the distribution of alpha globin gene mutation in the South of China, 356 patients with heterozygote alpha(+) thalassemia, heterozygote alpha(0) or homozygote alpha(+) thalassemia and 78 patients with HbH were analyzed. The gene diagnosis methods including Gap-PCR, nested-PCR, PCR-RE, PCR-SSCP, 4P-ASPCR and DNA sequence analysis were used. The results showed that among 356 patients, 295 patients with --SEA/alphaalpha (82.87%), 1 patient with alphaalpha/alpha-alpha(3.7) (0.28%), 3 patients with alphaalpha/alpha-alpha(4.2) (0.84%), 3 patients with alphaalpha/alpha(CS)alpha (0.84%), 1 patient with alphaalpha/alphaalpha(QS) (0.28%) and 2 patients with alphaalpha/alpha(Westmead) alpha (0.56%) were found. The homozygote with -alpha(4.2) or -alpha(3.7) was not found. In 78 patients with HbH, 29 patients with --SEA/alphaalpha(-3.7) (37.2%), 20 patients with --SEA/alphaalpha(-4.2) (25.6%), 19 patients with --SEA/alphaalpha(CS) (24.3%), 2 patients with --SEA/alphaalpha(QS) (2.6%) were detected, and other remaiming 8 patients were needed to be defined. Among the non-defined 8 patients, the synonymous mutation with C-->G transversion (GCC-GCG) at codon 65 in the exon 2 of alpha 2-globin gene was detected in 2 unrelated HbH patients came from Guangxi province. Whether it correlated with the phenotype of HbH disease or it is only a single nucleotide polymorphism site (SNPs), should be confirmed in the future. In addition, a set of gene diagnosis methods based on PCR to screen deletion and non-deletion genotypes of alpha-thalassemia in Chinese was improved. A new method, 4P-ASPCR, to detect Hb CS and Hb QS was also developed. The method was verified to be more accurate, time-saving and economic. In conclusion, the genotypes of alpha-thalassemia in Chinese are very complicated, the genotypes of alpha-thalassemia in Chinese need to be further studied, the results of this research probably have practical significance for the gene diagnosis or antenatal diagnosis of alpha-thalassemia in the South of China.

The present paper describes the structural analysis of an abnormal hemoglobin variant of alpha-chain found in a Chinese woman in the Hechi district of the Zhuang Autonomous Region of Guangxi, and finds it to be hemoglobin Handsworth (alpha 18(A16) Gly leads to Arg).

The alpha-thalassemia-2 (alpha-thal-2) genotype or mild alpha-thalassemia gene consists of a single structural alpha-globin gene on the chromosome that normally bears two alpha-globin genes. We used blot hybridization to investigate variation in the molecular organization of this genotype and to determine the distributions of these variations in the world population. Two different patterns of gene organization responsible for the alpha-thal-2 genotype were found: the first was the result of a 4.2-kilobase pair deletion involving the normal 5' alpha-globin gene (leftward deletion alpha-thal-2 genotype), and the second probably the result of a crossover deletion of a DNA fragment bridging the two normal alpha-globin genes (rightward deletion alpha-thal-2- genotype). The rightward deletion was found in all 9 Black subjects, all 8 Mediterranean subjects, and 4 of 13 Chinese subjects. The leftward deletion was found in four and the nondeletion alpha-thalassemia lesion was found in five of the nine remaining Chinese subjects. It is likely that these deletions are related to specific DNA sequences that determine DNA recombinational events.

The alpha-globin genes of five black Americans, two Chinese, and five Filipinos with HbH disease (an alpha-thalassemia state in which there is a single functional alpha gene) were analyzed by restriction endonuclease techniques. All subjects were found to have one chromosome 16, lacking both alpha genes, and another containing a single alpha gene (--/-alpha). Restriction endonuclease patterns of the DNA obtained from all 12 subjects were identical and compatible with unequal crossing-over as the mechanism of origin of the single alpha gene in these individuals.