scholarly journals TSHB R75G is a founder variant and prevalent cause of low or undetectable TSH in Indian Jews

2021 ◽  
Author(s):  
David Shaki ◽  
Marina Eskin-Schwartz ◽  
Noam Hadar ◽  
Emily Bosin ◽  
Lior Carmon ◽  
...  
Keyword(s):  
South Asian ◽  
Molecular Genetic ◽  
Allelic Loss ◽  
Carrier Rate ◽  
Loss Of Function ◽  
High Prevalence ◽  
Shared Ancestry ◽  
High Carrier ◽  
Bene Israel ◽  
Tsh Levels

Objective: Bi-allelic loss-of-function mutations in TSHB, encoding the beta-subunit of TSH, cause congenital non-goiterous hypothyroidism. Homozygosity for the TSHB p.R75G variant, previously described in South Asian individuals, does not alter TSH function, but abrogates its detection by some immune-detection-based platforms, leading to erroneous diagnosis of hyperthyroidism. We set out to identify and determine carrier rate of the p.R75G variant among clinically euthyroid Bene Israel Indian Jews, to examine possible founder origin of this variant worldwide and to determine phenotypic effects of its heterozygosity. Design: Molecular genetic studies of Bene Israel Jews and comparative studies with South Asian cohort. Methods: TSHB p.R75G variant tested by Sanger sequencing and RFLP. Haplotype analysis in the vicinity of the TSHB gene performed using SNP arrays. Results: Clinically euthyroid individuals with low or undetectable TSH levels from three apparently unrelated Israeli Jewish families of Bene Israel ethnicity, originating from the Mumbai region of India, were found heterozygous or homozygous for the p.R75G TSHB variant. Extremely high carrier rate of p.R75G TSHB in Bene Israel Indian Jews (~4%) was observed. A haplotype block of 239.7kB in the vicinity of TSHB shared by Bene Israel and individuals of South Asian origin was detected. Conclusions: Our findings highlight the high prevalence of the R75G TSHB variant in euthyroid Bene Israel Indian Jews, demonstrate that heterozygosity of this variant can cause erroneous detection of subnormal TSH levels, and show that R75G TSHB is an ancient founder variant, delineating shared ancestry of its carriers.

scholarly journals Study of molecular basis of thyroid dysgenesis

2018 ◽  
Vol 14 (2) ◽  
pp. 64-71
Author(s):  
Nina A. Makretskaya ◽  
Olga B. Bezlepkina ◽  
Anna A. Kolodkina ◽  
Alexey V. Kiyaev ◽  
Evgeny V. Vasilyev ◽  
...  
Keyword(s):  
Congenital Hypothyroidism ◽  
Molecular Basis ◽  
Molecular Genetic ◽  
Molecular Genetic Analysis ◽  
Ion Torrent ◽  
Loss Of Function ◽  
Thyroid Dysgenesis ◽  
Different Types ◽  
Generation Sequencing ◽  
Tsh Levels

Congenital hypothyroidism is a heterogeneous group of diseases, which is manifested by loss of function of the thyroid gland that affects infants from birth. 80–85% of cases are due to different types of thyroid dysgenesis. 5 genes have been described that are involved in the pathogenesis of thyroid dysgenesis: TSHR, PAX8, FOXE1, NKX2-1, NKX2-5. Aims. To evaluate the prevalence of mutations in the genes TSHR, PAX8, FOXE1, NKX2-1, NKX2-5 among patients with severe congenital hypothyroidism. Materials and methods. 161 patients (64 boys, 97 girls) with congenital hypothyroidism (TSH levels at neonatal screening or retesting greater than 90 mU/l) were included in the study. 138 subjects had different variants of thyroid dysgenesis, and 23 patients had normal volume of the gland. A next generation sequencing was used for molecular-genetic analysis. Sequencing was performed using PGM semiconductor sequencer (Ion Torrent, Life Technologies, USA) and a panel “Hypothyroidism” (Custom DNA Panel). Assessment of the pathogenicity of sequence variants were carried out according to the latest international guidelines (ACMG, 2015). Results. 13 patients had variants in thyroid dysgenesis genes (8,1%, 13/161): TSHR, n = 6; NKX2-1, n = 3; NKX2-5, n = 1; PAX8, n = 3; FOXE1, n = 0. Conclusions. Mutations in thyroid dysgenesis genes are a rare pathology. The majority of variants among our patients were identified in TSHR.

scholarly journals Correction: Bi-allelic loss of function variants in SLC30A5 as cause of perinatal lethal cardiomyopathy

2021 ◽  
Author(s):  
Johann Kaspar Lieberwirth ◽  
Pascal Joset ◽  
Anja Heinze ◽  
Julia Hentschel ◽  
Anja Stein ◽  
...  
Keyword(s):  
Allelic Loss ◽  
Loss Of Function

scholarly journals Clinical and genetic spectrum of glycogen storage disease in Iranian population using targeted gene sequencing

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zahra Beyzaei ◽  
Fatih Ezgu ◽  
Bita Geramizadeh ◽  
Mohammad Hadi Imanieh ◽  
Mahmood Haghighat ◽  
...  
Keyword(s):  
Clinical Symptoms ◽  
Molecular Genetic ◽  
Gene Sequencing ◽  
Glycogen Storage ◽  
Loss Of Function ◽  
Retrospective Case ◽  
Complex Disorders ◽  
Glycogen Storage Diseases ◽  
Targeted Gene Sequencing ◽  
Retrospective Case Study

AbstractGlycogen storage diseases (GSDs) are known as complex disorders with overlapping manifestations. These features also preclude a specific clinical diagnosis, requiring more accurate paraclinical tests. To evaluate the patients with particular diagnosis features characterizing GSD, an observational retrospective case study was designed by performing a targeted gene sequencing (TGS) for accurate subtyping. A total of the 15 pediatric patients were admitted to our hospital and referred for molecular genetic testing using TGS. Eight genes namely SLC37A4, AGL, GBE1, PYGL, PHKB, PGAM2, and PRKAG2 were detected to be responsible for the onset of the clinical symptoms. A total number of 15 variants were identified i.e. mostly loss-of-function (LoF) variants, of which 10 variants were novel. Finally, diagnosis of GSD types Ib, III, IV, VI, IXb, IXc, X, and GSD of the heart, lethal congenital was made in 13 out of the 14 patients. Notably, GSD-IX and GSD of the heart-lethal congenital (i.e. PRKAG2 deficiency) patients have been reported in Iran for the first time which shown the development of liver cirrhosis with novel variants. These results showed that TGS, in combination with clinical, biochemical, and pathological hallmarks, could provide accurate and high-throughput results for diagnosing and sub-typing GSD and related diseases.

scholarly journals A Novel Mutation of ATP7B Gene in a Case of Wilson Disease

Medicina ◽  
2021 ◽  
Vol 57 (2) ◽  
pp. 123
Author(s):  
Cigdem Yuce Kahraman ◽  
Ali Islek ◽  
Abdulgani Tatar ◽  
Özlem Özdemir ◽  
Adil Mardinglu ◽  
...  
Keyword(s):  
Wilson Disease ◽  
Novel Mutation ◽  
Molecular Genetic ◽  
Molecular Genetic Analysis ◽  
Compound Heterozygous ◽  
Atp7b Gene ◽  
Loss Of Function ◽  
Clinical Presentations ◽  
The Family ◽  
The Brain

Wilson disease (WD) (OMIM# 277900) is an autosomal recessive inherited disorder characterized by excess copper (Cu) storage in different human tissues, such as the brain, liver, and the corneas of the eyes. It is a rare disorder that occurs in approximately 1 in 30,000 individuals. The clinical presentations of WD are highly varied, primarily consisting of hepatic and neurological conditions. WD is caused by homozygous or compound heterozygous mutations in the ATP7B gene. The diagnosis of the disease is complicated because of its heterogeneous phenotypes. The molecular genetic analysis encourages early diagnosis, treatment, and the opportunity to screen individuals at risk in the family. In this paper, we reported a case with a novel, hotspot-located mutation in WD. We have suggested that this mutation in the ATP7B gene might contribute to liver findings, progressing to liver failure with a loss of function effect. Besides this, if patients have liver symptoms in childhood and/or are children of consanguineous parents, WD should be considered during the evaluation of the patients.

scholarly journals Bi-allelic loss-of-function variants in BCAS3 cause a syndromic neurodevelopmental disorder

2021 ◽  
Author(s):  
Holger Hengel ◽  
Shabab B. Hannan ◽  
Sarah Dyack ◽  
Sara B. MacKay ◽  
Ulrich Schatz ◽  
...  
Keyword(s):  
Neurodevelopmental Disorder ◽  
Allelic Loss ◽  
Loss Of Function

scholarly journals Bi-allelic Loss-of-Function Mutations in the NPR-C Receptor Result in Enhanced Growth and Connective Tissue Abnormalities

2018 ◽  
Vol 103 (2) ◽  
pp. 288-295 ◽  
Author(s):  
Eveline Boudin ◽  
Tjeerd R. de Jong ◽  
Tim C.R. Prickett ◽  
Bruno Lapauw ◽  
Kaatje Toye ◽  
...  
Keyword(s):  
Connective Tissue ◽  
Allelic Loss ◽  
Loss Of Function ◽  
Tissue Abnormalities

scholarly journals Mosaicism in Tuberous Sclerosis Complex: A Case Report, Literature Review, and Original Data from Danish Hospitals

2021 ◽  
pp. 98-105
Author(s):  
Julie Loft Nagel ◽  
Maja Patricia Smerdel ◽  
Lisbeth Birk Møller ◽  
Lotte Andreasen ◽  
Anette Bygum
Keyword(s):  
Tuberous Sclerosis ◽  
Tuberous Sclerosis Complex ◽  
Molecular Genetic ◽  
Genetic Diagnosis ◽  
Original Data ◽  
Hereditary Disease ◽  
Loss Of Function ◽  
Low Level ◽  
Multiple Organs ◽  
Organ Systems

Tuberous sclerosis complex (TSC) is an autosomal dominant hereditary disease with hamartomatous growths in multiple organs due to loss-of-function variants in TSC1 or TSC2. In approximately 15% of patients with clinical TSC, no pathogenic variant can be identified, and low-level mosaicism is suggested to be one of the reasons. Mosaicism is well-known in TSC and challenges the molecular genetic diagnosis. The advent of next-generation sequencing has improved the diagnostics in TSC including in patients with mosaicism. The TSC phenotype varies widely, and mosaic patients with TSC are often considered to have a milder phenotype. Here, the authors describe a patient with mosaic TSC with a 10% variant allele fraction and manifestations in three organ systems (skin, eyes, and kidneys). Furthermore, the authors studied existing literature about phenotypic organ manifestations in patients with mosaic TSC. No clear definition of the phenotype of patients with mosaic TSC could be established, but unilateral angiofibromas and the absence of tubers and a subependymal nodule could indicate mosaicism. The case shows that patients with low-level mosaic TSC can have multiple affected organ systems though still a mild clinical picture.

scholarly journals A NOTCH3 homozygous nonsense mutation in familial Sneddon syndrome with pediatric stroke

2020 ◽  
Author(s):  
Elli Katharine Greisenegger ◽  
Sara Llufriu ◽  
Angel Chamorro ◽  
Alvaro Cervera ◽  
Adriano Jimenez-Escrig ◽  
...  
Keyword(s):  
Nonsense Mutation ◽  
Underlying Disease ◽  
Allelic Loss ◽  
Pediatric Stroke ◽  
Loss Of Function ◽  
Whole Exome ◽  
Epidermal Growth ◽  
Epidermal Growth Factor Repeat ◽  
Homozygous Nonsense Mutation ◽  
Sneddon Syndrome

Abstract Sneddon syndrome is a rare disorder affecting small and medium-sized blood vessels that is characterized by the association of livedo reticularis and stroke. We performed whole-exome sequencing (WES) in 2 affected siblings of a consanguineous family with childhood-onset stroke and identified a homozygous nonsense mutation within the epidermal growth factor repeat (EGFr) 19 of NOTCH3, p.(Arg735Ter). WES of 6 additional cases with adult-onset stroke revealed 2 patients carrying heterozygous loss-of-function variants in putative NOTCH3 downstream genes, ANGPTL4, and PALLD. Our findings suggest that impaired NOTCH3 signaling is one underlying disease mechanism and that bi-allelic loss-of-function mutation in NOTCH3 is a cause of familial Sneddon syndrome with pediatric stroke.

scholarly journals Expression of apoptotic and proliferation factors in gastric mucosa of patients with systemic sclerosis correlates with form of the disease

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Katarina Boric ◽  
Snjezana Mardesic ◽  
Dusanka Martinovic Kaliterna ◽  
Mislav Radic ◽  
Ivana Tadin Hadjina ◽  
...  
Keyword(s):  
Systemic Sclerosis ◽  
Gastric Mucosa ◽  
Caspase 3 ◽  
Smooth Muscle Actin ◽  
Surface Epithelium ◽  
Gastric Disease ◽  
Loss Of Function ◽  
Ki 67 ◽  
Deposition Surface ◽  
High Prevalence

AbstractDespite high prevalence of patients with gastric disease in systemic sclerosis (SSc), its pathogenesis is still poorly understood. We immunohistochemically analysed biopsies of gastric mucosa (GM) in 5 controls and 15 patients with different forms of SSc: limited cutaneous (lc), diffuse cutaneous moderate (sys1) and severe (sys2). The number of positive cells was analysed by a Kruskall-Wallis test, P < 0.05 was considered statistically significant. Percentage of proliferating (Ki-67 positive) cells was highest in sys1 (3% in superficial and 4,6% in deeper parts of GM), which dropped to 1% in sys2. Percentage of α-smooth muscle actin (α-SMA) positive cells was 5% in controls, 9% in superficial GM, while in deeper GM rose from 7% to 19% in sys1 and sys2, thus indicating increased myofibroblast population. Caspase-3 positive apoptotic cells characterized 1,5–2% of controls, 8% of superficial and 6% of deeper GM cells in sys1. In sys2, apoptosis affected 50% of surface epithelial and gland cells and 30% of deeper glands, and correlated with increased fibrosis and decreased syndecan-1 expression. Our data demonstrate that sys1 is the most „active” proliferating form of SSc. Sys2 characterize collagen deposition, surface epithelium defects, extensive apoptosis and low proliferation, GM atrophy and loss of function.

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