Congenital adrenal hyperplasia (CAH) may rarely be associated with a deficiency in cytochrome P450 oxidoreductase (POR).
Chromosome: 7q11.2
Gene: POR (cytochrome P450 oxidoreductase)
Inheritance: autosomal recessive
Clinical features:
(1) disorders of sexual development in both males and females
(2) glucocorticoid (cortisol) deficiency, which may range from mild to severe
(3) skeletal malformations, consistent with Antley-Bixler syndrome
Newborn males: ambiguous genitalia (small penis, undescended testes)
Newborn female: vaginal atresia, fused labia minor, hypoplastic labia majora, enlarged clitoris
Urine steroid profile:
(1) high levels of pregnenolone
(2) high levels of progesterone metabolites
(3) low androgen metabolites
(4) high 17-hydroxyprogesterone metabolites
Serum profile:
(1) elevated serum 17-hydroxyprogesterone
(2) low serum levels of sex steroids
