Mutation screening of the sodium iodide symporter gene in a cohort of 105 China patients with congenital hypothyroidism.

OBJECTIVE Dyshormonogenetic congenital hypothyroidism (CH) was reported to be associated with a mutation in the sodium iodide symporter (NIS) gene. The present study was undertaken in the Guangxi Zhuang Autonomous Region of China, to determine the nature and frequency of NIS gene mutations among patients with CH due to dyshormonogenesis. SUBJECTS AND METHODS Blood samples were collected from 105 dyshormonogenetic CH patients in Guangxi Zhuang Autonomous Region, China, and genomic DNA was extracted from peripheral blood leukocytes. All exons of the NIS gene together with their exon-intron boundaries were screened by next-generation sequencing. RESULTS Two silent variations (T221T and T557T) and one missense variation (M435L), as well as two polymorphisms (rs200587561 and rs117626343) were found. CONCLUSIONS Our results indicate that the NIS mutation rate is very low in the Guangxi Zhuang Autonomous Region, China, and it is necessary to study mutations of other genes that have major effects on thyroid dyshormonogenesis and have not as yet been studied in this population.