Molecular Biology of Androgen Action in Genital Hypoplasia Associated with Congenital Growth Hormone Deficiency: A “Transitory Androgen Insensitivity Syndrome”?

Abstract

Androgen receptor analyses of foreskin homogenate from a boy with congenital growth hormone deficiency revealed at age 1 and 3 years a decreased number of cytosolic binding sites for testosterone (T) and dihydrotestosterone (DHT), compared with controls of similar age. Nuclear T receptor was not detectable at age 1 but showed abnormal high-binding capacity at age 3 years. Nuclear DHT receptor was within normal limits at both age 1 and 3 years. Receptor affinities were normal. Maximum reaction velocity of tissue-specific androgen 5α-reductase A5R was decreased at age 1 year but within the normal range at age 3 years. Stretched penile length was below the third percentile at age 1 and increased to a 25th percentile at age 3 years, respectively. As the receptor and A5R data seem to indicate a “catch-up” growth, i.e., normalization of the external genitalia, we therefore postulate a “transitory” course of an androgen insensitivity in this particular patient.

Key Words:

• Androgen receptors
• Micropenis
• GH-deficiency