Lipoid Congenital Adrenal Hyperplasia: An Uncommon Cause of Adrenal Insufficiency

Lipoid congenital adrenal hyperplasia (CAH) is a rare autosomal recessive disorder caused by defective synthesis of all steroids. Typical features include disorder of sex development, early-onset adrenal crisis and enlarged adrenal glands with fatty accumulation. Glucocorticoid and mineralocorticoid replacement therapy enables long-term survival. We report a case of lipoid CAH caused by mutation in the steroidogenic acute regulatory protein (StAR) gene. The patient had typical early-onset adrenal crisis at 2 months of age, normal-appearing female genitalia and a karyotype of 46, XY. Genetic analysis revealed a homozygous mutation at c.505G>A (p.Glu169Lys) in exon 5 of the StAR gene. To our knowledge this is the first case of classic lipoid CAH reported in the Portuguese population. StAR mutations should be considered in the differential diagnosis of newborn babies and infants with primary adrenal insufficiency with atypical presentation, allowing genetic counselling, guidance of follow-up and prevention of complications.