[Clinical characteristics and genetic analysis of four patients with central hypothyroidism due to IGSF1 gene variants].

OBJECTIVE: To explore the clinical manifestations and genetic characteristics of patients with congenital central hypothyroidism due to variants of IGSF1 gene. METHODS: Clinical data, results of genetic testing, and follow-up of four patients admitted to Children's Hospital of Soochow University during 2017 to 2021 were retrospectively analyzed. RESULTS: All of the four patients were males. Patient 1 had presented neonatal jaundice, patients 2 and 3 were admitted for growth retardation during childhood, and thyroid function test indicated slightly low free thyroxine (FT4), patient 4 was found to have reduced FT4 in the neonatal period. Genetic testing revealed that all of the four patients have harbored pathogenic variants of the IGSF1 gene, which were all inherited from their mothers. The thyroid functions in all patients were well controlled with oral levothyroxine and regular follow-up. CONCLUSION: Pathogenic variants of the IGSF1 gene probably underlay the congenital central hypothyroidism with a variety of clinical manifestations, and genetic testing can facilitate the diagnosis at an early stage.