Familial isolated glucocorticoid deficiency: three clinical cases and a brief overview of the current literature

Abstract

Familial isolated glucocorticoid deficiency (FIGD) is a rare form of primary adrenal insufficiency associated with the resistance of the adrenal cortex to the action of ACTH. This pathology manifests itself in the form of cortisol deficiency despite the normal mineralocorticoid function. Approximately 50% of all FIGD cases are attributable to mutations in two genes (melanocortin 2 receptor gene, MC2R, and melanocortin 2 receptor accessory protein gene, MRAP). In addition, the relationship between FIGD and mutations in nicotinamide nucleotide transhydrogenase gene, NNT, minichromosome maintenance gene, MCM4, and STAR is documented. No genetic defect was found in almost 25% of the cases of isolated deficiency of gucocorticoids. The clinical descriptions of the patients presenting with FIGD including its molecular-genetic diagnostics are of great interest for the understanding of this rare disease.