Dataset Information

The genetic characteristics of congenital hypothyroidism in China by comprehensive screening of 21 candidate genes.

ABSTRACT: OBJECTIVE:Congenital hypothyroidism (CH), the most common neonatal metabolic disorder, is characterized by impaired neurodevelopment. Although several candidate genes have been associated with CH, comprehensive screening of causative genes has been limited. DESIGN AND METHODS:One hundred ten patients with primary CH were recruited in this study. All exons and exon-intron boundaries of 21 candidate genes for CH were analyzed by next-generation sequencing. And the inheritance pattern of causative genes was analyzed by the study of family pedigrees. RESULTS:Our results showed that 57 patients (51.82%) carried biallelic mutations (containing compound heterozygous mutations and homozygous mutations) in six genes (DUOX2, DUOXA2, DUOXA1, TG, TPO and TSHR) involved in thyroid hormone synthesis. Autosomal recessive inheritance of CH caused by mutations in DUOX2, DUOXA2, TG and TPO was confirmed by analysis of 22 family pedigrees. Notably, eight mutations in four genes (FOXE1, NKX2-1, PAX8 and HHEX) that lead to thyroid dysgenesis were identified in eight probands. These mutations were heterozygous in all cases and hypothyroidism was not observed in parents of these probands. CONCLUSIONS:Most cases of congenital hypothyroidism in China were caused by thyroid dyshormonogenesis rather than thyroid dysgenesis. This study identified previously reported causative genes for 57/110 Chinese patients and revealed DUOX2 was the most frequently mutated gene in these patients. Our study expanded the mutation spectrum of CH in Chinese patients, which was significantly different from Western countries.

SUBMITTER: Sun F

PROVIDER: S-EPMC5958289 | biostudies-literature | 2018 Jun

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

The genetic characteristics of congenital hypothyroidism in China by comprehensive screening of 21 candidate genes.

Sun Feng F Zhang Jun-Xiu JX Yang Chang-Yi CY Gao Guan-Qi GQ Zhu Wen-Bin WB Han Bing B Zhang Le-Le LL Wan Yue-Yue YY Ye Xiao-Ping XP Ma Yu-Ru YR Zhang Man-Man MM Yang Liu L Zhang Qian-Yue QY Liu Wei W Guo Cui-Cui CC Chen Gang G Zhao Shuang-Xia SX Song Ke-Yi KY Song Huai-Dong HD

European journal of endocrinology 20180412 6

<h4>Objective</h4>Congenital hypothyroidism (CH), the most common neonatal metabolic disorder, is characterized by impaired neurodevelopment. Although several candidate genes have been associated with CH, comprehensive screening of causative genes has been limited.<h4>Design and methods</h4>One hundred ten patients with primary CH were recruited in this study. All exons and exon-intron boundaries of 21 candidate genes for CH were analyzed by next-generation sequencing. And the inheritance patter ...[more]

PMID: 29650690

Similar Datasets

Project description:BackgroundThe molecular etiology and the genotype-phenotype correlation of congenital hypothyroidism (CH) remain unclear.MethodsWe performed genetic analysis in 42 newborns with CH using whole-exome sequencing. Patients were divided into a single-gene group and a multi-gene group according to the number of affected genes, or divided into a monoallelic group, a biallelic group, and an oligogenic group according to the pattern of the detected variants. The clinical characteristics were compared between groups.ResultsThyroid dysgenesis (TD) was observed in 10 patients and goiter in 5 patients, whereas 27 patients had normal-sized gland-in-situ (GIS). We identified 58 variants in five genes in 29 patients. The genes with the most frequent variants were DUOX2 (70.7%), followed by TSHR (12.1%), DUOXA2 (10.3%), and TPO (5.2%). Variants in the genes causing dyshormonogenesis (DH) were more common than those in the genes causing TD (87.9% versus 12.1%). Among the patients with detected variants, 26 (89.7%) were harboring a single gene variant (single-gene group), which include 22 patients harboring biallelic variants (biallelic group) and four patients harboring monoallelic variants (monoallelic group). Three (10.3%) patients harbored variants in two or three genes (multi-gene group or oligogenic group). Compared with the single-gene group, the levothyroxine (L-T4) dose at 1 year of age was higher in the multi-gene group (p = 0.018). A controllable reduction in the L-T4 dose was observed in 25% of patients in the monoallelic group and 59.1% of patients in the biallelic group; however, no patients with such reduction in the L-T4 dose were observed in the oligogenic group.ConclusionsPatients with normal-sized GIS accounted for the majority of our cohort. Genetic defects in the genes causing DH were more common than those in the genes causing TD, with biallelic variants in DUOX2 being dominant. DH might be the leading pathophysiology of CH in Chinese individuals.

Project description:BackgroundDystrophinopathies are a set of severe and incurable X-linked neuromuscular disorders caused by mutations in the dystrophin gene (DMD). These mutations form a complex spectrum. A national registration network is essential not only to provide more information about the prevalence and natural history of the disease, but also to collect genetic data for analyzing the mutational spectrum. This information is extremely beneficial for basic scientific research, genetic diagnosis, trial planning, clinical care, and gene therapy.MethodsWe collected data from 1400 patients (1042 patients with confirmed unrelated Duchenne muscular dystrophy [DMD] or Becker muscular dystrophy [BMD]) registered in the Chinese Genetic Disease Registry from March 2012 to August 2017 and analyzed the genetic mutational characteristics of these patients.ResultsLarge deletions were the most frequent type of mutation (72.2%), followed by nonsense mutations (11.9%), exon duplications (8.8%), small deletions (3.0%), splice-site mutations (2.1%), small insertions (1.3%), missense mutations (0.6%), and a combination mutation of a deletion and a duplication (0.1%). Exon 45-50 deletion was the most frequent deletion type, while exon 2 duplication was the most common duplication type. Two deletion hotspots were calculated-one located toward the central part (exon 45-52) of the gene and the other toward the 5'end (exon 8-26). We found no significant difference between hereditary and de novo mutations on deletion hotspots. Nonsense mutations accounted for 62.9% of all small mutations (197 patients).ConclusionWe built a comprehensive national dystrophinopathy mutation database in China, which is essential for basic and clinical research in this field. The mutational spectrum and characteristics of this DMD/BMD group were largely consistent with those in previous international DMD/BMD studies, with some differences. Based on our results, about 12% of DMD/BMD patients with nonsense mutations may benefit from stop codon read-through therapy. Additionally, the top three targets for exon-skipping therapy are exon 51 (141, 13.5%), exon 53 (115, 11.0%), and exon 45 (84, 8.0%).

Project description:Congenital Hypothyroidism occurs in 1:3500 live births and is therefore the most common congenital endocrine disorder. A spectrum of defective thyroid morphology, termed thyroid dysgenesis, represents 80% of permanent CH cases. Although several candidate genes have been implicated in thyroid development, comprehensive screens failed to detect mutation carriers in a significant number of patients with non-syndromic TD. Due to the sporadic occurrence of TD, de novo chromosomal rearrangements are conceivably representing one of the molecular mechanisms participating in its aetiology. Recently, the use of array CGH technique has provided the ability to map these variations genomewide with high resolution. We performed an array CGH screen of 74 TD patients to determine the role of copy number variants (CNV) in the aetiology of the disease. We identified novel CNVs in 8.75% of all patients that have not been described as frequent variations in the healthy population. Affected patients presented with athyreosis or thyroid hypoplasia and in one case with associated heart malformation. We selected 74 patients with thyroid dysgenesis for array CGH analysis. All individuals were detected in neonatal screening programs and abnormal thyroid gland morphology was subsequently confirmed by ultrasound examination. Intragenic mutations in NKX2-1, FOXE1 and NKX2.5 had been previously excluded in phenotype characteristic individuals. PAX8 mutations were excluded in all patients with hypoplastic thyroids by direct sequencing of the coding exons 1-11. The study was approved by the local ethics committee. Genomic DNA of all subjects as well as of healthy controls was isolated from peripheral blood leucocytes using the Qiagen DNA blood mini kit (Qiagen, Hilden, Germany). Array-comparative genomic hybridization was carried as described previously {Erdogan, 2006 #142; Pinkel, 1998 #151}. In brief, sonicated patient- and control DNA was labeled by random priming with Cy3-dUTP and Cy5-dUTP (Bioprime Array CGH, Invitrogen, Carlsbad, CA), respectively, and hybridized onto a submegabase resolution tiling path BAC array, consisting of ~ 36 000 BAC clones obtained from several sources as described elsewhere {Fiegler, 2003 #198; Ishkanian, 2004 #196; Krzywinski, 2004 #197} . Step-by-step protocols are also provided at http://www.molgen.mpg.de/~abt_rop/molecular_cytogenetics/. Arrays were scanned with the G2565BA Agilent Microarray Scanner System (resolution 10 µm; PMT 100 % for Cy3/Cy5, respectively) (Agilent Inc. Santa Clara, CA) and analyzed using GENEPIX Pro 5.0 Software. Analysis and visualization of array CGH data were performed with our software package CGHPRO {Chen, 2005 #143}. For the assessment of copy number gains and losses, we used conservative log2 ratio thresholds of 0.3 and -0.3, respectively. Deviant signal intensity ratios involving three or more consecutive BAC clones were considered to be potentially pathogenic, unless they were covered by more than one known DNA copy number variant, as listed in the Database of Genomic Variants (http://projects.tcag.ca/variation/) or covered by > 50% of their length at least once in our reference set of 600 samples. Potentially pathogenic CNVs were verified by array CGH on a 244k oligonucleotide array from Agilent following the manufacturer’s instructions (Protocol-No. G4410-90010). Confirmed CNVs were tested for inheritance by co-hybridization of parental DNA on BAC arrays as described above. All chromosome coordinates are referring to the UCSC Genome Browser Assembly May 2004 (hg17/ NCBI Build 35; available at: http://genome.ucsc.edu/cgi-bin/hgGateway?hgsid=99195739&clade=vertebrate&org=Human&db=hg17). Cytoscape {Shannon, 2003 #201} was used for the elucidation of potential interactions between genes within the intervals of interest.

Dataset Information

The genetic characteristics of congenital hypothyroidism in China by comprehensive screening of 21 candidate genes.

Publications

The genetic characteristics of congenital hypothyroidism in China by comprehensive screening of 21 candidate genes.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets