We report on a patient with genetically confirmed adrenal hypoplasia congenita (AHC) whose presentation and laboratory abnormalities were consistent with the more common condition,
congenital adrenal hyperplasia (CAH). The patient presented with
failure to thrive and
salt wasting. General appearance showed marked
hyperpigmentation and normal male genitalia. He displayed mildly elevated
17-hydroxyprogesterone and markedly elevated
11-deoxycortisol levels at baseline and with
ACTH stimulation testing. Results were consistent with 11 β -
hydroxylase deficiency. He required
glucocorticoids and high doses of
mineralocorticoids. The marked elevation in
11-deoxycortisol directed our clinical reasoning away from a hypoplastic condition and towards a hyperplasic adrenal condition. Sequencing of the DAX1 gene (named for
dosage-sensitive sex reversal (DSS) locus and the AHC locus on the X chromosome) revealed a missense mutation. A review of the literature revealed that elevated
11-deoxycortisol levels have been noted in kindreds with DAX1 mutations, but only when measured very early in life. A mouse model has recently been described that displays elevated 11-deoxycorticosterone levels and evidence for
hyperplasia of the zona glomerulosa of the adrenal gland. We conclude that DAX1 testing may be considered in patients with laboratory evidence of 11 β -
hydroxylase deficiency, especially in those with severe
salt wasting.