LAUSR

Background SOX3 is essential for pituitary development normally at the earliest stages of development. In humans, variants of SOX3 can cause X-linked hypopituitarism with various clinical manifestations, with or without mental retardation. Case presentation We present an 8-year-old Chinese patient with congenital hypopituitarism who had a 6.180 Mb duplication on Xq26.3q27.1 including SOX3 , F9 , and eight other contiguous genes. The main complains of the boy was short stature. His height was 90.1 cm (− 5.87SDS), weight 11.5 kg (− 5.25SDS). He developed growth hormone (GH) deficiency, cryptorchidism and low thyroid function. Pituitary magnetic resonance imaging revealed the pituitary dysplasia. After diagnosis, levothyroxine was given for one month first, and the thyroid function basically returned to normal, but the growth situation did not improve at all. Then recombinant human GH was given, his height, growth rate and height SDS were improved significantly in the 2 years follow-up. The level of height SDS improved from − 5.87 SDS before treatment to − 3.27 SDS after the first year of treatment and − 1.78 SDS after the second years of treatment. Gonadal function and long-term prognosis of the patient still need further observation and follow-up. Conclusions This is the first case of Chinese male patient with multiple hypophysis dysfunction caused by SOX3 duplication, which will expand the range of phenotypes observed in patients with duplication of SOX3 .