Presence of 21-Hydroxylase Antibodies in a Boy with X-Linked Adrenal Hypoplasia Congenita

Abstract

Background: X-linked adrenal hypoplasia congenita is a rare cause of primary adrenal insufficiency (PAI) in children due to mutations in NR0B1/DAX1 (nuclear receptor subfamily 0, group B, member 1/dosage-sensitive sex reversal-adrenal hypoplasia congenita at the critical region of the X chromosome, gene 1). Another rare cause of PAI in children is autoimmune adrenal disease (AAD) which could be either isolated or as part of autoimmune polyglandular syndrome. Antibody to major auto-antigen, 21-hydroxylase, is highly specific for AAD. Methods: We report a now 19-month-old male with PAI due to NR0B1 gene mutation and positive adrenal antibodies. Initially, he presented at 15 days of life with isolated hypoaldosteronism which later unfolded into complete PAI. Data analysis was done via retrospective chart review. Results: Genetic analysis of the NR0B1 gene revealed a known hemizygous mutation in c.1069C>T; p.Gln357X. Simultaneously, he was noted to have positive 21-hydroxylase antibodies. Conclusion: According to our knowledge, this is the first case in the literature with NR0B1 mutation causing adrenal insufficiency with coexistent positive adrenal antibodies. In addition to his already compromised adrenal function due to NR0B1 mutation, he is now at risk for the development of associated autoimmune conditions requiring close follow-up.