Late onset 21-hydroxylase deficiency presenting as pre-pubertal gynaecomastia

Abstract

Pre-pubertal gynaecomastia has been described in 11β- but not in 21-hydoxylase deficiency. An 8-yr old boy presented with bilateral 5 cm breast buds: P2 G2 Testes 2/2 ml; height 138.5 cm bone age (TW2) 12.5 yrs. Serum hormone levels basally and post-ACTH are shown below. Prolactin was 254 μU/1, DOC 91 pmol/l supine PRA 3.0 ng/ml/hr, SHBG 155 nmol/l. GnRH stimulation at O' and 20': LH 2.6 and 4.2, FSH 5.4 and 6.3 iu/1. El 450 pmol/l. Capillary GLC of urine showed typical pattern of 21-OHase defect.Comparison of DHEAS/E1+E2 and A/E1+E2 gave values comparable to transient pubertal gynaecomastia range for bone age as reported by Moore et al (JCEM 1984 58: 492) and in which peripheral conversion of adrenal androgen to E1 and E2 is suggested as the cause of the condition. It remains unexplained why pre-pubertal gynaecomastia is rare in 21-OHase but not 11β-OHase deficiency.