Isolated FSH Deficiency in a Male

Abstract
This report describes the case of a 26-year-old man investigated because of infertility. The patient appeared healthy with normal sexual activity, physical appearance and karyotype. Repeated semen analyses showed a marked oligozoospermia. A testicular biopsy specimen revealed arrested spermatogenesis and normal Leydig cells. Hormone analyses were normal except for a markedly reduced serum FSH level. Only a few such cases have been previously reported.