Novel STAR Gene Variant of Congenital Lipoid Adrenal Hyperplasia With Testicular Adrenal Rests

A mutation in the steroidogenic acute regulatory protein (STAR) gene, which encodes a protein that plays a crucial role in steroid hormone synthesis, causes a severe form of congenital adrenal hyperplasia (CAH) known as lipoid CAH (LCAH). LCAH presents with primary adrenal insufficiency (PAI) as well as atypical genitalia. Individuals with LCAH require adrenal steroid hormone supplements for survival. Masculinization in males with STAR deficiency varies from incomplete to normal virilization. Radiological examinations reveal enlarged and lipid-laden adrenals. A 10-year-old boy born of second-degree consanguinity presented with weight gain and hyperpigmentation for 1 year. He was diagnosed with PAI at age 7 months and treated with hydrocortisone and fludrocortisone. Dynamic adrenal gland testing revealed undetectable hormone reserves. Imaging detected hypoplastic adrenals and a small testis with testicular adrenal rests (TART). Genetic analysis indicated a novel homozygous pathogenic variant of STAR in exon 7, c.814C > G(pArg272Gly) associated with LCAH (OMIM No. 201710). Testing revealed that asymptomatic family members and relatives were heterozygotes for the variant. The patient was diagnosed with nonclassic LCAH with hypoplastic adrenals and TART. Adequate hormone supplementation resulted in TART regression. This genetic variation is reported for the first time.