SAT-295 Low Dose rFSH Prior to HCG-rFSH Therapy in Kallmann Syndrome

[Background] Kallmann syndrome (KS) is known as a disorder characterized by hypogonadotropic hypogonadism and anosmia. Sato et al. reported that approximately 60% of Congenital male hypogonadotropic hypogonadism (CMHH) could not achieve sufficient spermatogenesis with the current hCG-rFSH combination therapy. [Objective] With the aim of improving gonadal function of KS, we treat KS patient with new methods proposed by Sato et al. and the effectiveness of low dose of rFSH mono-therapy followed by hCG-rFSH in an adolescent patient is discussed.[Case report] At the age of 14 years, he was diagnosed as KS because of cryptorchidism and micropenis in infancy and delayed puberty and hyposmia in adolescence, and identified with KAL1 mutation. The responses of LHRH stimulation were low levels (peak LH 0.85 mIU/mL, peak FSH 2.05 mIU/mL). The levels of testosterone responded for HCG stimulation test were 0.29 ng/mL before stimulation and 0.81 ng/mL after stimulation.From the age of 15 years, low dose rFSH (75 IU) was administered daily for 10 weeks, then switched to hCG-rFSH. Every six months, replacement doses of hCG and rFSH were increased. His height gain was 10.8 cm after treatment. Testicular volume was 2 mL when treatment began and increased to 6 mL in two years.Then, testosterone reached adult level. [Conclusion] Low dose rFSH therapy prior to hCG-rFSH to treat adolescent patients with KS seems to gain pubertal development slowly but improve testosterone secretion sufficiently.