AUTHOR=Wang Fengqi , Zang Yucui , Li Miaomiao , Liu Wenmiao , Wang Yangang , Yu Xiaolong , Li Hua , Wang Fang , Liu Shiguo 

TITLE=DUOX2 and DUOXA2 Variants Confer Susceptibility to Thyroid Dysgenesis and Gland-in-situ With Congenital Hypothyroidism

JOURNAL=Frontiers in Endocrinology

VOLUME=11

YEAR=2020

URL=https://www.frontiersin.org/journals/endocrinology/articles/10.3389/fendo.2020.00237

DOI=10.3389/fendo.2020.00237

ISSN=1664-2392

ABSTRACT=<p><bold>Background:</bold> Thyroid dysgenesis (TD), which is caused by gland developmental abnormalities, is the most common cause of congenital hypothyroidism (CH). In addition, advances in diagnostic techniques have facilitated the identification of mild CH patients with a gland-<italic>in-situ</italic> (GIS) with normal thyroid morphology. Therefore, TD and GIS account for the vast majority of CH cases.</p><p><bold>Methods:</bold> Sixteen known genes to be related to CH were sequenced and screened for variations by next-generation sequencing (NGS) in a cohort of 377 CH cases, including 288 TD cases and 89 GIS cases.</p><p><bold>Results:</bold> In our CH cohort, we found that <italic>DUOX2</italic> (21.22%) was the most commonly variant pathogenic gene, while <italic>DUOXA2</italic> was prominent in TD (18.75%) and <italic>DUOX2</italic> was prominent in GIS (34.83%). Both biallelic and triple variants of <italic>DUOX2</italic> were found to be most common in children with TD and children with GIS. The most frequent combination was <italic>DUOX2</italic> with <italic>DUOXA1</italic> among the 61 patients who carried digenic variants. We also found for the first time that biallelic <italic>TG, DUOXA2</italic>, and <italic>DUOXA1</italic> variants participate in the pathogenesis of TD. In addition, the variant p.Y246X in <italic>DUOXA2</italic> was the most common variant hotspot, with 58 novel variants identified in our study.</p><p><bold>Conclusion:</bold> We meticulously described the types and characteristics of variants from sixteen known gene in children with TD and GIS in the Chinese population, suggesting that <italic>DUOXA2</italic> and <italic>DUOX2</italic> variants may confer susceptibility to TD and GIS via polygenic inheritance and multiple factors, which further expands the genotype-phenotype spectrum of CH in China.</p>