A novel variant of the STAR gene: nonclassical presentation from Turkey.

Objectives: Lipoid congenital adrenal hyperplasia (LCAH) is a rare autosomal recessive disease caused by mutations in the steroidogenic acute regulatory protein (STAR) gene, expressed in the adrenal and gonadal tissues. In classical LCAH, individuals with 46, XY chromosomes present with a female appearance of the external genitalia due to insufficient androgen production. In the non-classical form, a milder phenotype is observed with male external genitalia. Here, we present a non-classical LCAH diagnosis with a newly identified c.266T>A (p.Ile89Asn) likely pathogenic homozygous variant in a 46, XY infant.

Case presentation: A three-month-and-thirteen-day-old male proband presented with clinical features of cortisol and mineralocorticoid deficiencies. The manifestation of salt-wasting syndrome occurred relatively late, and although the external genitalia appeared male, there was a mild virilization defect. The combination of mild impairment in androgen production and severe salt-wasting syndrome is an intriguing finding in our patient. Peripheral blood samples were obtained from the patient and his family. The newly identified variant, determined by next-generation sequencing analysis, was confirmed by segregation analysis showing carrier status in both parents.

Conclusions: We aim to contribute to the literature by elucidating molecular mechanisms by presenting an atypical presentation and a newly identified variant.