Whole exome sequencing identified a heterozygous KCNJ2 missense variant underlying autosomal dominant familial hypokalemic periodic paralysis in a Pakistani family

2019 ◽  
Vol 32 (12) ◽  
pp. 1385-1389
Author(s):  
Aman Ullah ◽  
Ranjha Khan ◽  
Muhammad Naeem

Abstract Background Familial hypokalemic periodi9c paralysis (hypoKPP) is a rare autosomal dominant disorder characterized by episodic paralytic attacks caused by fall in blood potassium. CACNA1S, SCN4A or KCNJ2 variants can cause hypoKPP. Case presentation We investigated a Pakistani family affected with autosomal dominant familial hypoKPP through whole exome sequencing (WES). A heterozygous KCNJ2 missense variant c.919A > G was found segregating with the disease phenotype in the family. Conclusions The KCNJ2 missense variant is the likely cause of the disorder in the affected family. The finding should help improve antenatal screening and genetic counselling of this family.

2022 ◽  
Vol 12 ◽  
Author(s):  
Fengyu Che ◽  
Jiangang Zhao ◽  
Yujuan Zhao ◽  
Zhi Wang ◽  
Liyu Zhang ◽  
...  

Aim: To determine the etiology of a Chinese family with thrombocytopenia by analyzing the clinical features and genetic variation.Methods: Clinical profiles and genomic DNA extracts of the family members were collected for the study. Whole exome sequencing and Sanger sequencing was used to detect the associated genetic variation and verify the family co-segregation respectively. Bioinformatics analysis assessed the pathogenicity of missense mutations.Results: The study reported a 3-generation pedigree including eight family members with thrombocytopenia. The platelet counts of the patients were varied, ranging from 38 to 110 × 109/L (reference range: 150–450 x 109/L). The mean volumes and morphology of the sampled platelet were both normal. The bleeding abnormality and mitochondriopathy were not observed in all the patients. Clinical signs of thrombocytopenia were mild. A novel heterozygous missense variant c.79C > T (p.His27Tyr) was identified in CYCS gene associated with autosomal dominant thrombocytopenia.Conclusion: We report the first large family with autosomal dominant non-syndromic thrombocytopenia 4 in a Chinese family, a novel heterozygous missense variant c.79C > T (p.His27Tyr) was identified. The whole exome sequencing is an efficient tool for screening the variants specifically associated with the disease. The finding enriches the mutation spectrum of CYCS gene and laid a foundation for future studies on the correlation between genotype and phenotype.


2020 ◽  
pp. 014556132091062
Author(s):  
Yongli Zhang ◽  
Qi Tang ◽  
Ruoyan Xue ◽  
Xiaohui Zhu ◽  
Hua Yang ◽  
...  

Background: Otosclerosis is a focal lesion of the inner ear. The role of genetic factors in the pathogenesis of otosclerosis has received increasing attention. We analyzed the clinical manifestations, inheritance pattern, and pathogenic genes in a family with otosclerosis. Methods: We collected clinical data and generated a family pedigree. High-throughput second-generation sequencing technology was used to identify candidate genes by performing whole-exome sequencing of 7 members of the family, and Sanger sequencing was performed to validate candidate gene mutations in the 7 family members. Results: Otosclerosis was characterized by autosomal dominant inheritance in this family. Whole-exome sequencing did not reveal mutation sites in known deafness-related genes. However, a c.2209A > G (p.T737A) mutation was detected in exon 6 of the SP1 gene, which is associated with the COL1A1 gene. This mutation was a pathogenic mutation, and Sanger sequencing confirmed that this mutation cosegregated with the clinical phenotype among the family members. Conclusions: The pattern of otosclerosis in this family is consistent with autosomal dominant inheritance, and the SP1 gene, harboring the c.2209A > G (p.T737A) mutation in exon 6, may be the causative gene of otosclerosis in this family.


2020 ◽  
Vol 2020 ◽  
pp. 1-6
Author(s):  
Xiu-Feng Huang ◽  
Li Sun ◽  
Chunwu Zhang ◽  
Zhenni Zhou ◽  
Hui Chen ◽  
...  

Gout is a common inflammatory arthritis triggered by monosodium urate deposition after longstanding hyperuricemia. In the general community, the disease is largely polygenic in genetic architecture, with many polymorphisms having been identified in gout or urate-associated traits. In a small proportion of cases, rare high penetrant mutations associated with monogenic segregation of the disease in families have been demonstrated to be disease causative. In this study, we recruited a two-generation pedigree with early-onset gout. To elucidate the genetic predisposition, whole-exome sequencing (WES) was performed. After comprehensive variant analyses and cosegregation testing, we identified a missense variant (c.277C>A, p.L93M) in SLC16A9, an extremely rare variant in genetic databases. Moreover, in silico assessments showed strong pathogenicity. This variant cosegregated with the disease phenotype perfectly in the family and is located in a highly conserved functional domain. A few studies supported our results of the association between SLC16A9 and gout and serum urate levels. In conclusion, we provide the first evidence for the association of rare missense in SLC16A9 with early-onset gout. These findings not only expand our current understanding of gout but also may have further implications for the treatment and prevention of gout.


2020 ◽  
Vol 48 (9) ◽  
pp. 030006052095364
Author(s):  
XinYu Tan ◽  
SongNian Hu ◽  
Zongyu Xie ◽  
Hailiang Mei ◽  
Yang Liu ◽  
...  

Objectives Normokalemic periodic paralysis (NormoKPP) of skeletal muscle is an autosomal dominant disorder caused by mutations in the gene encoding voltage-gated sodium channel protein type 4 subunit alpha ( SCN4A), which leads to ion channel dysfunction. Little is known about the relationship between genotype and the clinical symptoms of NormoKPP. The present study aimed to evaluate the genetic variation in a large Chinese family with NormoKPP. The patients in this pedigree did not respond to saline treatment, but calcium gluconate treatment was effective. Methods We performed a series of clinical examinations and genetic analyses, using whole-exome and Sanger sequencing, to examine the mutation status of SCN4A in a Chinese family segregating for NormoKPP. Results Whole-exome sequencing revealed a c.2111C>T substitution in SCN4A in most of the affected family members. This mutation results in the amino acid substitution p.T704M. Conclusions These results support a causative role of this mutation in SCN4A in NormoKPP, and provide information about the relationship between genotype and atypical clinical symptoms.


2019 ◽  
Author(s):  
Qi Yang ◽  
Jin Wang ◽  
Xiaoxian Tian ◽  
Fei Chen ◽  
Jing Lan ◽  
...  

Abstract Brachydactyly type A1 (BDA-1, MIM 112500) is a genetically heterogeneous autosomal-dominant disorder mainly characterized by shortening or missing of the middle phalanges. Brachydactyly type A1 (BDA-1) is caused by heterozygous pathogenic variants in a specific region of the N-terminal active fragment of Indian Hedgehog (IHH). In this study, we reported a Chinese family with 8 members affected with Brachydactyly type A1. After performing whole-exome sequencing in the proband, we identified a novel heterozygous missense variant c.299A>G (p.D100G) at the mutational hotspot of IHH gene. The variant co-segregated with BDA-1 in the pedigree, showed 100% penetrance for phalange phenotype with variable expressivity. This finding expanded the Brachydactyly type A1-related mutational spectrum of IHH gene.


Author(s):  
Qing Li ◽  
Chengfeng Wang ◽  
Wei Li ◽  
Zaiqiang Zhang ◽  
Shanshan Wang ◽  
...  

AbstractPontine autosomal dominant microangiopathy and leukoencephalopathy (PADMAL) is a rare hereditary cerebral small vessel disease. We report a novel collagen type IV alpha 1 (COL4A1) gene mutation in a Chinese family with PADMAL. The index case was followed up for 6 years. Neuroimaging, whole-exome sequencing, skin biopsy, and pedigree analysis were performed. She initially presented with minor head injury at age 38. MRI brain showed chronic lacunar infarcts in the pons, left thalamus, and right centrum semiovale. Extensive workup was unremarkable except for a patent foramen ovale (PFO). Despite anticoagulation, PFO closure, and antiplatelet therapy, the patient had recurrent lacunar infarcts in the pons and deep white matter, as well as subcortical microhemorrhages. Whole-exome sequencing demonstrated a novel c.*34G > T mutation in the 3′ untranslated region of COL4A1 gene. Skin biopsy subsequently demonstrated thickening of vascular basement membrane, proliferation of endothelial cells, and stenosis of vascular lumen. Three additional family members had gene testing and 2 of them were found to have the same heterozygous mutation. Of the 18 individuals in the pedigree of 3 generations, 12 had clinical and MRI evidence of PADMAL. The mechanisms of both ischemic and hemorrhagic stroke are likely the overexpression of COLT4A1 in the basement membrane and frugality of the vessel walls. Our findings suggest that the novel c.*34G > T mutation appears to have the same functional consequences as the previously reported COL4A1 gene mutations in patients with PADMAL and multi-infarct dementia of Swedish type.


Author(s):  
Bixia Zheng ◽  
Steve Seltzsam ◽  
Chunyan Wang ◽  
Luca Schierbaum ◽  
Sophia Schneider ◽  
...  

Abstract Background Congenital anomalies of the kidneys and urinary tract (CAKUT) constitute the most common cause of chronic kidney disease in the first three decades of life. Variants in four Forkhead box (FOX) transcription factors have been associated with CAKUT. We hypothesized that other FOX genes, if highly expressed in developing kidney, may also represent monogenic causes of CAKUT. Methods We here performed whole exome sequencing (WES) in 541 families with CAKUT and generated 4 lists of CAKUT candidate genes: A) 36 FOX genes showing high expression during renal development, B) 4 FOX genes known to cause CAKUT to validate list A; C) 80 genes that we identified as unique potential novel CAKUT candidate genes when performing WES in 541 CAKUT families, and D) 175 genes identified from WES as multiple potential novel CAKUT candidate genes. Results To prioritize potential novel CAKUT candidates in FOX gene family, we overlapped 36 FOX genes (list A) with list C and D of WES-derived CAKUT candidates. Intersection with list C, identified a de novo FOXL2 in-frame deletion in a patient with eyelid abnormalities and ureteropelvic junction obstruction, and a homozygous FOXA2 missense variant in a patient with horseshoe kidney. Intersection with list D, identified a heterozygous FOXA3 missense variant in a CAKUT family with multiple affected individuals. Conclusion We hereby identified FOXL2, FOXA2 and FOXA3 as novel monogenic candidate genes of CAKUT, supporting the utility of a paralog-based approach to discover mutated genes associated with human disease.


Seizure ◽  
2017 ◽  
Vol 51 ◽  
pp. 200-203
Author(s):  
Zain Aslam ◽  
Eungi Lee ◽  
Mazhar Badshah ◽  
Muhammad Naeem ◽  
Changsoo Kang

2017 ◽  
Vol 176 (5) ◽  
pp. K9-K14 ◽  
Author(s):  
Sandrine Caburet ◽  
Ronit Beck Fruchter ◽  
Bérangère Legois ◽  
Marc Fellous ◽  
Stavit Shalev ◽  
...  

Context PCOS is a heterogeneous condition characterized by hyperandrogenism and chronic anovulation and affects about 10% of women. Its etiology is poorly known, but a dysregulation of gonadotropin secretion is one of its hallmarks. Objective As the etiology of PCOS is unclear, we have performed a genome-wide analysis of a consanguineous family with three sisters diagnosed with PCOS. Methods Whole-exome sequencing and Sanger sequencing confirmation. Results Whole-exome sequencing allowed the detection of the missense variant rs104893836 located in the first coding exon of the GNRHR gene and leading to the p.Gln106Arg (p.Q106R) substitution. Sanger sequencing of all available individuals of the family confirmed that the variant was homozygous in the three affected sisters and heterozygous in both parents. Conclusions This is the first description of a GNRHR gene mutation in patients diagnosed with PCOS. Although we do not exclude a possible interaction of the identified variant with the genetic background and/or the environment, our result suggests that genetic alterations in the hypothalamo–pituitary axis may play role in the pathogenesis of PCOS.


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