scholarly journals New insights from unbiased panel and whole-exome sequencing in a large Chinese cohort with disorders of sex development

2019 ◽  
Vol 181 (3) ◽  
pp. 311-323 ◽  
Author(s):  
Yufei Xu ◽  
Yirou Wang ◽  
Niu Li ◽  
Ruen Yao ◽  
Guoqiang Li ◽  
...  

Context Diagnosis of non-chromosomal type disorders of sex development (DSD) has long been challenging. There is still no research on overview of a large Chinese DSD cohort. Objective To determine the etiologic diagnosis through unbiased large-scale panel sequencing and whole-exome sequencing (WES) within a large Chinese DSD cohort. Design Patients were recruited according to the inclusion criteria of DSD. The applied panel contains 2742 known disease-causing genes, including all known diagnostic genes for DSD. Methods Targeted panel sequencing (TPS) was performed, and identified candidate variants were verified. Variant pathogenicities were evaluated according to established guidelines. WES was performed for randomly selected negative samples. Results This study included 125 patients. Seventy-five variants were identified by TPS and 31 variants were reported for the first time. Pathogenic and likely pathogenic variants accounted for 38.7 and 30.7%, respectively. On the basis of clinical certainty, etiologic diagnostic rates of 46.9 and 10.3% were obtained for 46,XY and 46,XX DSD patients, respectively. We reported novel candidate genes (BMPR1B, GNAS, GHR) and regions of copy number variants outside the expected DSD genotype–phenotype correlation and determined a founder mutation (SRD5A2 p.R227Q) in patients with 5α-reductase deficiency. Further WES in randomly selected negative samples identified only one among 14 negative samples as a variant of uncertain significance, indicating that WES did not improve the diagnostic rate. Conclusions This is the first report of the applying unbiased TPS in a large Chinese cohort of patients with 46,XY and 46,XX DSD. Our findings expand the gene, mutation and phenotype spectra of the rare types of DSD in the Chinese population and provide new insight into the current understanding of the etiologies of DSD.

2020 ◽  
Vol 4 (Supplement_1) ◽  
Author(s):  
Yardena Tenenbaum Rakover ◽  
Osnat Admoni ◽  
Ghadir Elias Assad ◽  
Shira London ◽  
Marie Noufi Barhoum ◽  
...  

Abstract Background: Disorders of sex development (DSD) are classified as a congenital discrepancy between external genitalia, gonadal and chromosomal sex. Despite extensive laboratory and imaging investigations, the etiology of DSD is unknown in more than 50% of patients and the diagnosis is often delayed to the second decade of life. Our objective was to evaluate the etiology of DSD by whole-exome sequencing (WES) in children in whom hormonal and candidate gene approaches had not identified the etiology. Methods: Nine patients diagnosed with DSD (eight 46,XY and one 46,XX) were enrolled. Patients underwent hormonal evaluation, including ACTH, GnRH and hCG tests. Candidate genes were sequenced in accordance with the hormonal results. WES was performed for the probands and their parents. Results: The eight 46,XY patients presented with micropenis, cryptorchidism and hypospadias at birth and the 46,XX patient with fusion of the labia majora. In six of the nine patients (66%), a pathogenic mutation was identified by WES that explained the phenotype: four known DSD-causing genes—POR, CHD7, HSD17B3 and WT1—and two novel genes—BMP4 and RFXP2. In three patients, variants of unknown significance were found. An 11-y-old boy had a novel de-novo mutation in BMP4. In humans, mutations in this gene, encoding bone morphogenetic protein 4, are associated with autosomal dominant microphthalmia. BMP4 is expressed in the urethral epithelium and has a role in the development of external genitalia and the pituitary. This is the first report of a BMP4 mutation in a child with DSD. A 12-y-old boy had a mutation in RFXP2, encoding insulin-like 3 hormone receptor, which has been previously reported in adult males with cryptorchidism. This is the first case of an RFXP2 mutation in a child with DSD. Conclusions: WES has a crucial role in early diagnosis of the etiology of DSD, making extensive endocrine testing unnecessary, and has important implications for sex of rearing decisions.


2021 ◽  
Author(s):  
Yardena Tenenbaum Rakover ◽  
Osnat Admoni ◽  
Gadir Elias-Assad ◽  
Shira London ◽  
Marie Noufi Barhoum ◽  
...  

Objective: Disorders of sex development (DSD) are defined as congenital conditions in which development of chromosomal, gonadal and anatomical sex is atypical. Despite wide laboratory and imaging investigations, the etiology of DSD is unknown in over 50% of patients. Methods: We evaluated the etiology of DSD by whole-exome sequencing (WES) at a mean age of 10 years in nine patients for whom extensive evaluation, including hormonal, imaging and candidate gene approaches, had not identified an etiology. Results: The eight 46,XY patients presented with micropenis, cryptorchidism and hypospadias at birth and the 46,XX patient presented with labia majora fusion. In seven patients (78%), pathogenic variants were identified for RXFP2, HSD17B3, WT1, BMP4, POR, CHD7 and SIN3A. In two patients, no causative variants were found. Mutations in three genes were reported previously with different phenotypes: an 11-year-old boy with a novel de novo variant in BMP4; such variants are mainly associated with microphthalmia and in few cases with external genitalia anomalies in males, supporting the role of BMP4 in the development of male external genitalia; a 12-year-old boy with a known pathogenic variant in RXFP2, encoding insulin-like 3 hormone receptor, and previously reported in adult men with cryptorchidism; an 8-year-old boy with syndromic DSD had a de novo deletion in SIN3A. Conclusions: Our findings of molecular etiologies for DSD in 78% of our patients indicate a major role for WES in early DSD diagnosis and management, and highlights the importance of rapid molecular diagnosis in early infancy for sex of rearing decisions.


2020 ◽  
Author(s):  
Pengfei Liang ◽  
Fengping Chen ◽  
Shujuan Wang ◽  
Qiong Li ◽  
Wei Li ◽  
...  

Abstract Background: Hereditary non-syndromic hearing loss (NSHL) has a high genetic heterogeneity with >152 genes identified as associated molecular causes. The present study aimed to detect the possible damaging variants of the deaf probands from six unrelated Chinese families.Methods: After excluding the mutations in the most common genes, GJB2 and SLC26A4, 12 probands with prelingual deafness and autosomal recessive inheritance were evaluated by whole-exome sequencing (WES). All the candidate variants were verified by Sanger sequencing in all patients and their parents.Results: Biallelic mutations were identified in all deaf patients. Among these six families, 10 potentially causative mutations, including 3 reported and 7 novel mutations, in 3 different deafness-associated autosomal recessive (DFNB) genes (MYO15A, COL11A2, and CDH23) were identified. The mutations in MYO15A were frequent with 7/10 candidate variants. Sanger sequencing confirmed that these mutations segregated with the hearing loss of each family.Conclusions: Next-generation sequencing (NGS) approach becomes more cost-effective and efficient when analyzing large-scale genes compared to the conventional polymerase chain reaction-based Sanger sequencing, which is often used to screen common deafness-related genes. The current findings further extend the mutation spectrum of hearing loss in the Chinese population, which has a positive significance for genetic counseling.


2016 ◽  
Vol 15 ◽  
pp. CIN.S36612 ◽  
Author(s):  
Lun-Ching Chang ◽  
Biswajit Das ◽  
Chih-Jian Lih ◽  
Han Si ◽  
Corinne E. Camalier ◽  
...  

With rapid advances in DNA sequencing technologies, whole exome sequencing (WES) has become a popular approach for detecting somatic mutations in oncology studies. The initial intent of WES was to characterize single nucleotide variants, but it was observed that the number of sequencing reads that mapped to a genomic region correlated with the DNA copy number variants (CNVs). We propose a method RefCNV that uses a reference set to estimate the distribution of the coverage for each exon. The construction of the reference set includes an evaluation of the sources of variability in the coverage distribution. We observed that the processing steps had an impact on the coverage distribution. For each exon, we compared the observed coverage with the expected normal coverage. Thresholds for determining CNVs were selected to control the false-positive error rate. RefCNV prediction correlated significantly ( r = 0.96–0.86) with CNV measured by digital polymerase chain reaction for MET (7q31), EGFR (7p12), or ERBB2 (17q12) in 13 tumor cell lines. The genome-wide CNV analysis showed a good overall correlation (Spearman's coefficient = 0.82) between RefCNV estimation and publicly available CNV data in Cancer Cell Line Encyclopedia. RefCNV also showed better performance than three other CNV estimation methods in genome-wide CNV analysis.


2021 ◽  
Vol 12 ◽  
Author(s):  
Rishika P. Sakaria ◽  
Parul G. Zaveri ◽  
Shannon Holtrop ◽  
Jie Zhang ◽  
Chester W. Brown ◽  
...  

Kabuki syndrome is a rare multiple anomalies syndrome associated with mutations in KMT2D or KDM6A. It is characterized by infantile hypotonia, developmental delay and/or intellectual disability, long palpebral fissures with everted lateral third of the lower eyelids and typical facial features. Intracranial anomalies occur infrequently in patients with KS and holoprosencephaly has only been recently described. Additionally, though congenital heart diseases are common in patients with KS, to our knowledge truncus arteriosus has never been reported in a patient with KS. We present an unusual case of KS in an infant with holoprosencephaly and truncus arteriosus with partial anomalous pulmonary venous return. Duo whole exome sequencing in our patient identified a pathogenic nonsense variant in exon 10 of KMT2D (c.2782C > T; p. Gln928*) establishing the diagnosis. This report further expands the phenotypic spectrum of patients with Kabuki syndrome and emphasizes the utility of performing large scale sequencing in neonates with multiple congenital anomalies.


2020 ◽  
Vol 22 (8) ◽  
pp. 1041-1049
Author(s):  
Évelin A. Zanardo ◽  
Fabíola P. Monteiro ◽  
Samar N. Chehimi ◽  
Yanca G. Oliveira ◽  
Alexandre T. Dias ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document