A novel nonsense variant (p.Arg1293Ter) of the immunoglobulin superfamily 1 (IGSF1) associated with congenital hypogonadotropic hypogonadism and central hypothyroidism

Individuals with deletions and/or pathogenic variants of the Immunoglobulin superfamily 1 (IGSF1) gene may show congenital central hypothyroidism (CCH) (1–3). In addition, these individuals may have PRL deficiency and, in a small number of cases, GH deficiency. Furthermore, the onset of puberty tends to be delayed, and is often accompanied by giant testes. Despite the early replacement of thyroid hormone, CCH may be accompanied by developmental disorders and attention deficit hyperactivity syndrome (2, 3). However, asymptomatic cases have also been reported. We report the identification of a novel nonsense variant (p.Arg1293Ter) of IGSF1 in a young male patient with congenital hypogonadotropic hypogonadism (CHH), CCH, and GH deficiency.