scholarly journals Whole Exome Sequencing Aids The Diagnosis of Fetal Skeletal Dysplasia

2020 ◽  
Author(s):  
Hui Tang ◽  
Qin Zhang ◽  
Linliang Yin ◽  
Jingjing Xiang ◽  
Jing Wang ◽  
...  

Abstract Background: Skeletal dysplasia is a complex group of bone and cartilage disorders with strong clinical and genetical heterogeneousity. Several types have prenatal phenotypes. And it is difficult to make a molecular diagnosis rapidly due to lacking family history and non-specific and limited clinical symptoms in utero. This study aims to diagnose 16 Chinese fetuses with skeletal dysplasia.Methods: Single nucleotide polymorphism-array (SNP-array) was performed in 12 of 16 samples. If no microdeletions or microreplications related to skeletal dysplasia were detected, whole-exome sequencing (WES) was adopted. And the last four cases only got whole-exome sequencing for analyzing copy number variants and single nucleotide variations at the same time.Results: Among the 16 cases, 12 patients received definitive diagnosis and we detected one deletion in DMD gene by SNP-array and 15 variants of 6 genes including FGFR3, COL1A1, COL1A2, ALPL, HSPG2 and DYNC2H1. 8 variants of COL1A1, COL1A2, ALPL and HSPG2 are novel. And somatic mosaicism in asymptomatic parent with mutations in COL1A1 or COL1A2 was observed.Conclusions: In general, our study expanded the prenatal phenotypes in Duchenne muscular dystrophy (DMD)/ Becker muscular dystrophy (BMD), found 8 novel variants and elucidated that the utilization of whole-exome sequencing improved the diagnosis yield of skeletal dysplasia and provided useful genetic counseling guidance for parents.

2021 ◽  
Vol 12 ◽  
Author(s):  
Hui Tang ◽  
Qin Zhang ◽  
Jingjing Xiang ◽  
Linliang Yin ◽  
Jing Wang ◽  
...  

Skeletal dysplasia is a complex group of bone and cartilage disorders with strong clinical and genetic heterogeneity. Several types have prenatal phenotypes, and it is difficult to make a molecular diagnosis rapidly. In this study, the genetic cause of 16 Chinese fetuses with skeletal dysplasia were analyzed, and 12 cases yielded positive results including one deletion in DMD gene detected by SNP-array and 14 variants in other 6 genes detected by whole exome sequencing (WES). In addition, somatic mosaicism was observed. Our study expanded the pathogenic variant spectrum and elucidated the utilization of WES in improving the diagnosis yield of skeletal dysplasia.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Xin Jiang ◽  
Dong Chen

Abstract Background Degenerative lumbar spinal stenosis (DLSS) is a common lumbar disease that requires surgery. Previous studies have indicated that genetic mutations are implicated in DLSS. However, studies on specific gene mutations are scarce. Whole-exome sequencing (WES) is a valuable research tool that identifies disease-causing genes and could become an effective strategy to investigate DLSS pathogenesis. Methods From January 2016 to December 2017, we recruited 50 unrelated patients with symptoms consistent with DLSS and 25 unrelated healthy controls. We conducted WES and exome data analysis to identify susceptible genes. Allele mutations firstly identified potential DLSS variants in controls to the patients’ group. We conducted a site-based association analysis to identify pathogenic variants using PolyPhen2, SIFT, Mutation Taster, Combined Annotation Dependent Depletion, and Phenolyzer algorithms. Potential variants were further confirmed using manual curation and validated using Sanger sequencing. Results In this cohort, the major classification variant was missense_mutation, the major variant type was single nucleotide polymorphism (SNP), and the major single nucleotide variation was C > T. Multiple SNPs in 34 genes were identified when filtered allele mutations in controls to retain only patient mutations. Pathway enrichment analyses revealed that mutated genes were mainly enriched for immune response-related signaling pathways. Using the Novegene database, site-based associations revealed several novel variants, including HLA-DRB1, PARK2, ACTR8, AOAH, BCORL1, MKRN2, NRG4, NUP205 genes, etc., were DLSS related. Conclusions Our study revealed that deleterious mutations in several genes might contribute to DLSS etiology. By screening and confirming susceptibility genes using WES, we provided more information on disease pathogenesis. Further WES studies incorporating larger DLSS patient cohorts are required to comprehend the genetic landscape of DLSS pathophysiology fully.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Yahya Benbouchta ◽  
Imane Cherkaoui Jaouad ◽  
Habiba Tazi ◽  
Hamza Elorch ◽  
Mouna Ouhenach ◽  
...  

Abstract Background Corneal dystrophies (CDs) are a heterogeneous group of bilateral, genetically determined, noninflammatory bilateral corneal diseases that are usually limited to the cornea. CD is characterized by a large variability in the age of onset, evolution and visual impact and the accumulation of insoluble deposits at different depths in the cornea. Clinical symptoms revealed bilateral multiple superficial, epithelial, and stromal anterior granular opacities in different stages of severity among three patients of this family. A total of 99 genes are involved in CDs. The aim of this study was to identify pathogenic variants causing atypical corneal dystrophy in a large Moroccan family and to describe the clinical phenotype with severely different stages of evolution. Case presentation In this study, we report a large Moroccan family with CD. Whole-exome sequencing (WES) was performed in the three affected members who shared a phenotype of corneal dystrophy in different stages of severity. Variant validation and familial segregation were performed by Sanger sequencing in affected sisters and mothers and in two unaffected brothers. Whole-exome sequencing showed a novel heterozygous mutation (c.1772C > A; p.Ser591Tyr) in the TGFBI gene. Clinical examinations demonstrated bilaterally multiple superficial, epithelial and stromal anterior granular opacities in different stages of severity among three patients in this family. Conclusions This report describes a novel mutation in the TGFBI gene found in three family members affected by different phenotypic aspects. This mutation is associated with Thiel-Behnke corneal dystrophy; therefore, it could be considered a novel phenotype genotype correlation, which will help in genetic counselling for this family.


2021 ◽  
Vol 13 ◽  
Author(s):  
Lin Sun ◽  
Jianye Zhang ◽  
Ning Su ◽  
Shaowei Zhang ◽  
Feng Yan ◽  
...  

Background: Sporadic dementias generally occur in older age and are highly polygenic, which indicates some patients transmitted in a poly-genes hereditary fashion.Objective: Our study aimed to analyze the correlations of genetic features with clinical symptoms in patients with degenerative dementia.Methods: We recruited a group of 84 dementia patients and conducted the whole exome sequencing (WES). The data were analyzed focusing on 153 dementia-related causing and susceptible genes.Results: According to the American College of Medical Genetics and Genomics (ACMG) standards and guidelines, we identified four reported pathogenic variants, namely, PSEN1 c.A344G, APP c.G2149A, MAPT c.G1165A, and MAPT c.G742A, one reported likely pathogenic variant, namely, PSEN2 c.G100A, one novel pathogenic variants, SQSTM1 c.C671A, and three novel likely pathogenic variants, namely, ABCA7 c.C4690T, ATP13A2 c.3135delC, and NOS3 c.2897-2A > G. 21 variants with uncertain significance in PSEN2, C9orf72, NOTCH3, ABCA7, ERBB4, GRN, MPO, SETX, SORL1, NEFH, ADCM10, and SORL1, etc., were also detected in patients with Alzheimer’s disease (AD) and frontotemporal dementia (FTD).Conclusion: The new variants in dementia-related genes indicated heterogeneity in pathogenesis and phenotype of degenerative dementia. WES could serve as an efficient diagnostic tool for detecting intractable dementia.


2021 ◽  
Author(s):  
Jiliang Zhai ◽  
Jiahao Li ◽  
Yu Zhao ◽  
Xing Wei

Abstract Background The clinical presentations of ossification of spinal ligament (OSL) are majorly myelopathy and/or radiculopathy, with serious neurological pathology resulting in paralysis of extremities and disturbances of motility (motor function) lowering the quality of life. Currently, studies find that missense single nucleotide polymorphisms (SNPs) play a vital role in the susceptibility for complex diseases. Methods In the present study, we used whole exome sequencing (WES) method to explore variants in exomes and found out novel potential responsible genes for OSL. Genomic DNA was extracted from ligamentum flavum collected from 5 OSL patients and 5 control patients. Whole-exome sequencing was then performed, while variation forecasts and conservation examination were subsequently assessed. Results 8 common SNP variants were exhibited in all 5 subjects of OSL, presented in the genes of GRHL2, CUL3, WHAMM, IL17RD, POM121L12, SLC26A8 and PTPN23. After screened with numbers of samples and additional screenings with deleterious Polyphen2_HDIV_score, Polyphen2_HVAR_score and SIFT, 4 common SNP variants were displayed in 4 subjects of OSL, presented in the genes of KRT84, KIF1B, NRAP and CETN1. 7 common SNP variants were existed in 3 subjects of OSL, presented in the genes of CCT3, ANLN, ESRRB, SRBD1, ODF3L1, BRAT1 and RBP3. Conclusion We found out novel potential variants in several genes, especially WHAMM, KIF1B and ESRRB, which represented potentially pathogenic mutations in patients with OSL.


2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Lara Pemberton ◽  
Robert Barker ◽  
Anna Cockell ◽  
Vijaya Ramachandran ◽  
Andrea Haworth ◽  
...  

Abstract Background Osteocraniostenosis (OCS) is a rare genetic disorder characterised by premature closure of cranial sutures, gracile bones and perinatal lethality. Previously, diagnosis has only been possible postnatally on clinical and radiological features. This study describes the first prenatal diagnosis of OCS. Case presentation In this case prenatal ultrasound images were suggestive of a serious but non-lethal skeletal dysplasia. Due to the uncertain prognosis the parents were offered Whole Exome Sequencing (WES), which identified a specific gene mutation in the FAMIIIa gene. This mutation had previously been detected in two cases and was lethal in both perinatally. This established the diagnosis, a clear prognosis and allowed informed parental choice regarding ongoing pregnancy management. Conclusions This case report supports the use of targeted WES prenatally to confirm the underlying cause and prognosis of sonographically suspected abnormalities.


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