Primary Adrenocortical Insufficiency Case Series: Genetic Etiologies More Common than Expected.

BACKGROUND/AIMS Primary adrenal insufficiency (AI) is an important cause of morbidity in children. Our objectives were: (1) to describe the clinical presentation of children with new-onset primary AI, and (2) to identify monogenic causes of primary AI in children. METHODS Chart review and mutation detection in candidate genes were conducted for 11 patients with primary AI. RESULTS The likely cause of AI was determined in 9 patients. One had a homozygous MC2R mutation associated with familial glucocorticoid deficiency. Two had the same homozygous mutation in the AIRE gene which is associated with type 1 autoimmune polyglandular syndrome. One patient had a heterozygous change in this gene of undetermined significance. Five were homozygous for the previously reported p.R188C STAR mutation causing nonclassic lipoid congenital adrenal hyperplasia, representing the largest cohort of such patients from a single geographic area. In the remaining 2 patients, no clear etiology was identified. CONCLUSIONS We recommend genetic testing for patients who have negative anti-adrenal antibodies or suggestive family history. Diagnosing a genetic etiology can provide information about prognosis and treatment, and is therefore beneficial for patients. Our high proportion of patients with nonclassic lipoid congenital adrenal hyperplasia likely represents a founder effect.