Isolated FSH Deficiency
Isolated FSH deficiency was first described in a young woman with primary amenorrhea. A homozygous deletion of two base pairs affecting the FSHβ gene was later reported to account for isolated FSH deficiency in an Italian woman. A few other cases of isolated FSH deficiency were described with compound heterozygous or homozygous mutations in the coding region of the FSHβ gene. Previously we report clinical, biochemical, and molecular analyses of a young male patient affected with isolated FSH deficiency and azoospermia with no evidence of mutations in the coding sequence of the FSHβ gene. The number of patients with isolated FSH deficiency reported to date in the literature is limited. FSH is thought to be essential for both steroid production necessary for puberty and gametogenesis in human males and females. Although FSHß gene mutations are considered to be relatively rare, their identification increases our understanding of normal reproductive physiology.