Isolated follicle-stimulating hormone (FSH) deficiency without mutation of the FSHbeta gene and successful treatment with human menopausal gonadotropin.

OBJECTIVE: To describe the case of isolated follicle-stimulating hormone (FSH) deficiency without mutation of the FSHbeta gene.
DESIGN: Case report.
SETTING: Division of Endocrinology and Metabolism, Department of Internal Medicine, Faculty of Medicine, Kagawa University, Kagawa, Japan. PATIENT(S): A 22-year-old man referred for infertility, azoospermia, and isolated FSH deficiency. INTERVENTION(S): The patient's FSHbeta gene was sequenced. Pituitary function at baseline and after repeated GnRH administration was evaluated. Testicular biopsy was performed. The patient was treated with human menopausal gonadotropin (hMG). MAIN OUTCOME MEASURE(S): Pathologic examination revealed hypospermatogenesis with isolated FSH deficiency without mutation of the FSHbeta gene. RESULT(S): The FSH levels remained below the normal range despite repeated GnRH stimulation. Hypospermatogenesis was confirmed by testicular biopsy. After 6 months of hMG treatment, spermatogenesis was successfully induced. CONCLUSION(S): We report the case of an infertile male with isolated FSH deficiency without any evidence of mutation in the FSHbeta gene.