Chunyun Fu1, Shiyu Luo1, Shujie Zhang1, Jin Wang1, Haiyang Zheng1, Qi Yang1, Bobo Xie1, Xuyun Hu1, Xin Fan1, Jingsi Luo1, Rongyu Chen1, Jiasun Su1, Yiping Shen2, Xuefan Gu3, Shaoke Chen4. 1. Department of Genetic Metabolism, Children's Hospital, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning 530003, People's Republic of China; GuangXi Center for Birth Defects Research and Prevention, Nanning 530003, People's Republic of China. 2. Department of Genetic Metabolism, Children's Hospital, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning 530003, People's Republic of China; Boston Children's Hospital, Harvard Medical School, Boston 02115, MA, United States. 3. Endocrinology and Genetic Metabolism of Institute for Pediatric Research, Xinhua Hospital Affiliated to Shanghai Jiaotong University School of Medicine, Shanghai 200092, People's Republic of China. Electronic address: gu_xuefan@163.com. 4. Department of Genetic Metabolism, Children's Hospital, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning 530003, People's Republic of China; GuangXi Center for Birth Defects Research and Prevention, Nanning 530003, People's Republic of China. Electronic address: chenshaoke123@163.com.
Abstract
BACKGROUND: Defects in the human dual oxidase 2 (DUOX2) gene are reported to be one of the major causes of congenital hypothyroidism (CH). This study was set to examine the DUOX2 mutation spectrum and prevalence among Chinese CH and subclinical congenital hypothyroidism (SCH) patients and to define the relationships between DUOX2 genotypes and clinical phenotypes. METHODS: Peripheral venous blood samples were collected from 192 CH/SCH patients in Guangxi Zhuang Autonomous Region of China. All exons and their exon-intron boundary sequences of the 11 known CH associated genes including DUOX2 were screened by next-generation sequencing (NGS). RESULTS: NGS analysis of DUOX2 revealed 18 rare non-polymorphic variants in 57 CH/SCH patients. Sequencing of other CH candidate genes in the 57 patients revealed 2 thyroglobulin (TG) variants. All variants included 11 known mutations, 8 novel variants in DUOX2 and one novel variant in TG, among which three variants p.K530X, p.L1343F and p.R683L are highly recurrent in our patient cohort. 35 (83%) of the 42 patients with one or two DUOX2 pathogenic variants turned out to be SCH or transient congenital hypothyroidism (TCH), whereas 13 (87%) of the 15 patients with three or more DUOX2 pathogenic variants are associated with permanent congenital hypothyroidism (PCH). The accumulation of defects in DUOX2 contribute to the more severe disease regarding thyroid stimulating hormone (TSH) levels, free thyroxine (FT4) levels and initial dose of l-thyroxine (L-T4). CONCLUSION: Our study expanded the mutational spectrum of the DUOX2 and TG genes and provided the best estimation of the DUOX2 mutation rate (29%) for CH/SCH patients in Guangxi Zhuang Autonomous Region of China. Most one or two DUOX2 pathogenic variants turned out to be SCH or TCH, whereas patients with three or more DUOX2 pathogenic variants were mostly associated with PCH. The coexistence of multiple pathogenic variants may have contributed to the severity of the hypothyroid condition.
BACKGROUND: Defects in the humandual oxidase 2 (DUOX2) gene are reported to be one of the major causes of congenital hypothyroidism (CH). This study was set to examine the DUOX2 mutation spectrum and prevalence among Chinese CH and subclinical congenital hypothyroidism (SCH) patients and to define the relationships between DUOX2 genotypes and clinical phenotypes. METHODS: Peripheral venous blood samples were collected from 192 CH/SCH patients in Guangxi Zhuang Autonomous Region of China. All exons and their exon-intron boundary sequences of the 11 known CH associated genes including DUOX2 were screened by next-generation sequencing (NGS). RESULTS: NGS analysis of DUOX2 revealed 18 rare non-polymorphic variants in 57 CH/SCH patients. Sequencing of other CH candidate genes in the 57 patients revealed 2 thyroglobulin (TG) variants. All variants included 11 known mutations, 8 novel variants in DUOX2 and one novel variant in TG, among which three variants p.K530X, p.L1343F and p.R683L are highly recurrent in our patient cohort. 35 (83%) of the 42 patients with one or two DUOX2 pathogenic variants turned out to be SCH or transient congenital hypothyroidism (TCH), whereas 13 (87%) of the 15 patients with three or more DUOX2 pathogenic variants are associated with permanent congenital hypothyroidism (PCH). The accumulation of defects in DUOX2 contribute to the more severe disease regarding thyroid stimulating hormone (TSH) levels, free thyroxine (FT4) levels and initial dose of l-thyroxine (L-T4). CONCLUSION: Our study expanded the mutational spectrum of the DUOX2 and TG genes and provided the best estimation of the DUOX2 mutation rate (29%) for CH/SCH patients in Guangxi Zhuang Autonomous Region of China. Most one or two DUOX2 pathogenic variants turned out to be SCH or TCH, whereas patients with three or more DUOX2 pathogenic variants were mostly associated with PCH. The coexistence of multiple pathogenic variants may have contributed to the severity of the hypothyroid condition.
Authors: Catherine Peters; Adeline K Nicholas; Erik Schoenmakers; Greta Lyons; Shirley Langham; Eva G Serra; Neil J Sebire; Marina Muzza; Laura Fugazzola; Nadia Schoenmakers Journal: Thyroid Date: 2019-06 Impact factor: 6.568