5 alpha-reductase deficiency in patients with micropenis

Area of Science:

• Endocrinology
• Genetics
• Pediatric Urology

Background:

• The enzyme 5 alpha-reductase (5 alpha R) converts testosterone to dihydrotestosterone, crucial for penile development.
• 5 alpha R deficiency (5 alpha RD) has been linked to micropenis and genital ambiguity.
• Egypt has a notable prevalence of 5 alpha RD among intersex patients.

Purpose of the Study:

• To investigate the role of 5 alpha RD in the development of micropenis among Egyptian patients with abnormal sexual development.
• To differentiate the contribution of 5 alpha RD in isolated micropenis versus ambiguous genitalia.

Main Methods:

• Studied 29 Egyptian patients with abnormal sexual development, categorized into isolated micropenis, microphallus with genital ambiguity, and genital ambiguity with normal phallus.
• Assessed 5 alpha R activity by measuring testosterone/dihydrotestosterone (T/DHT) ratios.
• Utilized basal T/DHT ratios in pubertal subjects and human chorionic gonadotropin (HCG) stimulation tests in prepubertal subjects.

Main Results:

• The incidence of 5 alpha RD was highest in patients with ambiguous genitalia and micropenis (50%).
• 5 alpha RD was less frequent in isolated micropenis (11.1%) and ambiguous genitalia with normal phallus (12.5%).
• Isolated micropenis demonstrated a heterogeneous etiology, with 5 alpha RD playing a minimal role.

Conclusions:

• Isolated micropenis is a complex condition with varied causes, and 5 alpha RD is not a primary etiological factor.
• 5 alpha RD appears to correlate with penile length in patients with intersex conditions and ambiguous genitalia.