Clinical Characteristics and Spermatogenesis in Patients with Congenital Hypogonadotropic Hypogonadism Caused by FGFR1 Mutations.

Patients with FGFR1 mutations have a higher prevalence of cryptorchidism and smaller testicular volume. Although patients with FGFR1 mutations have a similar rate of success for spermatogenesis compared to that of the mutation-negative patients, a longer treatment period was required and a lower sperm concentration was achieved.