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Non-immune hydrops fetalis (NIHF) is abnormal accumulation of serous fluid in ≥2 interstitial spaces with no evidence of maternal red cell alloimmunization. Leaving a few treatable conditions, it is generally considered as a sign of poor fetal outcome. Bi-allelic variants in THSD1 have been found to be to be associated with phenotypes ranging from lethal NIHF to persistent edema. Here, we report a family with non-immune hydrops in two successive pregnancies. Whole exome sequencing in second pregnancy identified a homozygous truncating variant in THSD1 (NM_018676:c.892G>T:p.Glu298Ter). Postnatal follow up showed gradual resolution of the accumulated fluid and normal development. This report further strengthens the association of variants in THSD1 with NIHF. [ABSTRACT FROM AUTHOR]

Epidermolysis bullosa (EB) is a genodermatosis characterized by skin fragility and blisters with variable severity. Patients with Dystrophic EB (DEB) or Junctional EB (JEB) mainly present to clinic due to greater functional impairment. Pathogenic sequence variations in COL7A1 are implicated in DEB. We have tried to decipher the molecular spectrum and genotype phenotype correlation of 21 Indian patients with EB. Next generation sequencing (NGS) was performed to determine the pathogenic variants. Sanger sequencing was also done for validation of the variants in eleven individuals. Pathogenic variants were detected in 20 individuals (diagnostic yield of 95%). Majority of them (90%) had sequence variation in COL7A1 while two had pathogenic variants in ITGB4 and KRT14 respectively. Out of the 18 patients confirmed to have DEB, 3 had Dominant DEB (DDEB) whereas 15 patients had Recessive DEB (RDEB). Amongst 23 sequence variations identified, 12 were found to be novel (3 were missense, 5 were premature termination codon variants while 4 were splice-site changes). Genotype phenotype correlation was noted with milder manifestations in those with dominant inheritance types. Exact molecular diagnosis can be ascertained by NGS in majority of cases. • Twenty one individuals clinically suspected with Epidermolysis bullosa(EB) were evaluated for pathogenic variations. • First of its kind study in the subcontinent as molecular diagnosis was done by NGS without undergoing painful skin biopsies. • Majority were found to have Dystrophic EB and recessive mode of inheritance. • Identified 52% novel pathogenic variants in the cohort, further expanding the genotypic spectrum of such genodermatoses. • ~40% of the mutated alleles in COL7A1 were located in exons 3–4 and 73–75 suggesting these may be the hot-spots in Indian population. [ABSTRACT FROM AUTHOR]

Haemophilia-A is a rare, X-linked recessive inherited disease affects males and females are carrier results in prolonged bleeding after minor injuries, procedures or surgery. Spontaneous or recurrent bleeding may occur in deep muscles, joints but intracranial haemorrhage can be dangerous. Women with a family history of bleeding disorder, personal history of bleeding (menorrhagia, mucous membrane, postoperative bleeding and PPH) or a prolonged activated partial thromboplastin time (aPTT) should be screened for haemophilia by measuring coagulation factor VIII level during hospital visits for these reason or antenatal care (ANC). Female heterozygote carriers may have variable presentation of bleeding due to reduced levels of clotting FVIII and may experience excessive bleeding due to gynaecologic issues, during spontaneous abortion, medical termination of pregnancy or invasive prenatal diagnostic techniques in first trimester of pregnancy, antepartum and postpartum haemorrhage in later part of gestation and after delivery. [ABSTRACT FROM AUTHOR]

BACKGROUND: One of the complications of chronic transfusions in thalassemia is the development of red cell alloimmunization. AIMS: The aim of the study was to determine the frequency, specificity of red cell alloantibodies, and factors influencing alloimmunization in multiply transfused thalassemia patients. MATERIALS AND METHODS: The study was carried out prospectively on beta-thalassemia patients over 10 months. Plasma samples were used for antibody screening and identification using the column agglutination technique. Patients' clinical, laboratory, and transfusion details were obtained from hospital information system and patient files. STATISTICAL ANALYSIS: Continuous variables were reported as median and quartile, whereas categorical variables were provided as numbers and proportions. P < 0.05 was considered statistically significant. RESULTS: Out of 255 patients, 17 (6.6%) patients developed alloantibodies. Alloimmunized patients had significantly higher median ages at their first transfusions (1 year vs. 0.5 years; P = 0.042) than nonalloimmunized patients. Alloimmunized patients had significantly higher conjugated bilirubin (P = 0.016) and serum ferritin (P = 0.007). The majority of alloantibodies had specificity toward K antigen, followed by E, C, D, JKa, and JKb antigens. Alloimmunized patients received more units per year than nonalloimmunized patients (median, 30 vs. 24 units; P < 0.001). The average transfusion interval time between two successive transfusions showed a significant difference (P < 0.001). CONCLUSIONS: The prevalence of alloimmunization in thalassemia patients in North India is relatively low. Since most of the alloantibodies belong to Rh and Kell blood group system, extended phenotype-matched blood for Rh and Kell will be helpful in further preventing or decreasing the development of alloantibodies in multiply transfused thalassemia patients. [ABSTRACT FROM AUTHOR]

We report the third case of FADS due to biallelic DOK7 variants, which further strengthens the association of DOK7 with this lethal phenotype and lack of genotype phenotype correlation. [ABSTRACT FROM AUTHOR]

Background: Von Hippel–Lindau (VHL) syndrome is a familial cancer syndrome caused by mutations in VHL gene. It is characterized by the formation of benign and malignant tumors like retinal angioma, cerebellar hemangioblastoma, spinal hemangioblastoma, renal cell carcinoma, pheochromocytoma, pancreatic and renal cysts, and endolymphatic sac tumors. Germline mutations in VHL gene have also been reported in isolated VHL-associated tumors. VHL gene is a small gene with 3 coding exons and can be easily tested even in a resource constraint setting. Objective: To describe clinical presentation and estimate the diagnostic yield of in VHL and VHL-associated tumors. Methods: This is a descriptive study in a hospital setting. Here, we describe the clinical and molecular data of 69 patients with suspected VHL or having VHL-associated tumors. Sanger sequencing of coding sequences and conserved splice sites of VHL gene were done in all patients. Multiplex ligation-dependent probe amplification (MLPA) of VHL gene to detect large deletions/duplications was performed for 18 patients with no pathogenic sequence variations. Results: Among tumor types at presentation, pheochromocytoma was seen in 49% (34/69), hemangioblastoma was seen in 30% (21/69), and renal cell carcinoma was seen in 7% (5/69). Rest had other tumors like paraganglioma, endolymphatic sac papillary tumors, cerebellar astrocytoma and pancreatic cyst. Seven patients (10%) had more than one tumor at the time of diagnosis. Pathogenic variations in VHL gene were identified in 31probands by Sanger sequencing; 18 were missense, 2 nonsense and 2 small indels. A heterozygous deletion of exon 3 was detected by MLPA in one patient among 18 patients for whom MLPA was done. Overall, the molecular yield was 46% cases (32/69). Family history was present in 7 mutation positive cases (22%). Overall, 11 families (16%) opted for pre-symptomatic mutation testing in the family. Conclusions: Mutation testing is indicated in VHL and VHL-associated tumors. The testing facility is easy and can be adopted easily in developing countries like India. The yield is good, and with fairly high incidence of familial cases, molecular testing can help in pre-symptomatic testing and surveillance. [ABSTRACT FROM AUTHOR]

MPS II is an X linked recessive lysosomal storage disorder with multi-system involvement and marked molecular heterogeneity. In this study, we explored the clinical and molecular spectrum of 144 Indian patients with MPS II from 130 unrelated families. Clinical information was collected on a predesigned clinical proforma. Sanger method was employed to sequence all the exons and exon/intron boundaries of the IDS gene. In cases where causative variation was not detected by Sanger sequencing, MLPA and RFLP were performed to identify large deletions/duplications and complex rearrangements. Cytogenetic microarray was done in one patient to see the breakpoints and extent of deletion. In one patient with no detectable likely pathogenic or pathogenic variation, whole-genome sequencing was also performed. Novel variants were systematically assessed by in silico prediction software and protein modelling. The pathogenicity of variants was established based on ACMG criteria. An attempt was also made to establish a genotype-phenotype correlation. Positive family history was present in 31% (41/130) of patients. Developmental delay and intellectual disability were the main reasons for referral. Macrocephaly, coarse facies and dysostosis were present in almost all patients. Hepatosplenomegaly, joint contractures and short stature were the characteristic features, seen in 87% (101/116), 67.8% (74/109) and 41.4% (41/99) patients respectively. Attenuated phenotype was seen in 32.6% (47/144) patients, while severe phenotype was seen in 63% (91/144) patients. The detection rate for likely pathogenic or pathogenic variants in our cohort is 95.5% (107/112) by Sanger sequencing, MLPA and RFLP. We also found two variants of unknown significance, one each by Sanger sequencing and WGS. Total of 71 variants were identified by Sanger sequencing and 29 of these variants were found to be novel. Amongst the novel variants, there was a considerable proportion (51%) of frameshift variants (15/29). Almost half of the causative variants were located in exon 3,8 and 9. A significant genotype-phenotype correlation was also noted for both known and novel variants. This information about the genotype spectrum and phenotype will be helpful for diagnostic and prognostic purposes. [ABSTRACT FROM AUTHOR]

Microcephaly is a frequent feature of neurodevelopmental disorders (NDDs). Our study presents the heterogeneous spectrum of genetic disorders in patients with microcephaly either in isolated form or in association with other neurological and extra-neural abnormalities. We present data of 91 patients from 87 unrelated families referred to our clinic during 2016–2020 and provide a comprehensive clinical and genetic landscape in the studied cohort. Molecular diagnosis using exome sequencing was made in 45 families giving a yield of 51.7%. In 9 additional families probable causative variants were detected. We identified disease causing variations in 49 genes that are involved in different functional pathways Among these, 36 had an autosomal recessive pattern, 8 had an autosomal dominant pattern (all inherited de novo), and 5 had an X-linked pattern. In 41 probands where sequence variations in autosomal recessive genes were identified 31 were homozygotes (including 16 from non-consanguineous families). The study added 28 novel pathogenic/likely pathogenic variations. The study also calls attention to phenotypic variability and expansion in spectrum as well as uncovers genes where microcephaly is not reported previously or is a rare finding. We here report phenotypes associated with the genes for ultra-rare NDDs with microcephaly namely ATRIP , MINPP1 , PNPLA8 , AIMP2 , ANKLE2 , NCAPD2 and TRIT1. [ABSTRACT FROM AUTHOR]

Pycnodysostosis is an autosomal recessive skeletal dysplasia with easily recognizable clinical features and marked molecular heterogeneity. In this study, we explored the clinical and molecular spectrum of 25 Indian patients with pycnodysostosis from 20 families. Clinical information was collected on a predesigned clinical proforma. Sanger method was employed to sequence all the exons and exon/intron boundaries of the CTSK gene. Novel variants were systematically assessed by prediction softwares and protein modelling. The pathogenicity of variant was established based on ACMG-AMP criteria. An attempt was also made to establish a genotype-phenotype correlation and devise a diagnostic scoring system based on clinical and radiological findings. Consanguinity and positive family history were present in 65% (13/20) and 45% (9/20) of the families respectively. Short stature and fractures were the predominant presenting complaints and was evident in 96% (24/25) and 32% (8/25) of affected individuals respectively. Gestalt facial phenotype and acro-osteolysis were present in 76% (19/25) and 82.6% (19/23) of the individuals respectively. Hepatosplenomegaly was present in 15% (3/20) of the individuals with one of them having severe anaemia. Causative sequence variations were identified in all of them. A total of 19 variants were identified from 20 families amongst which 10 were novel. Homozygous variants were identified in 90% (18/20) families. Amongst the novel variants, there was a considerable proportion (40%) of frameshift variants (4/10). No significant genotype-phenotype correlation was noted. Scoring based on clinical and radiological findings led to the proposal that a minimum of 2 scores in each category is required in addition to high bone density to diagnose pycnodysostosis with certainty. This study delineated the genotypic and phenotypic characterisation of Indian patients with pycnodysostosis with identification of 10 novel variants. We also attempted to develop a clinically useful diagnostic scoring system which requires further validation. [ABSTRACT FROM AUTHOR]