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.

中文翻译：

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IGSF1基因变异所致中枢性甲状腺功能减退症4例临床特征及基因分析[J].

目的探讨IGSF1基因变异所致先天性中枢性甲状腺功能减退症患者的临床表现及遗传特征。方法回顾性分析苏州大学附属儿童医院2017年至2021年收治的4例患者的临床资料、基因检测结果及随访情况。结果 4 例患者均为男性。患者 1 出现新生儿黄疸，患者 2 和 3 因儿童期生长迟缓入院，甲状腺功能检查显示游离甲状腺素 (FT4) 略低，患者 4 发现新生儿期 FT4 降低。基因检测显示，这四名患者都携带有 IGSF1 基因的致病变异，这些变异均遗传自其母亲。所有患者的甲状腺功能均通过口服左旋甲状腺素和定期随访得到良好控制。结论 IGSF1基因致病变异可能是先天性中枢性甲状腺功能减退症临床表现多样的基础，基因检测有助于早期诊断。