Clinical features and StAR gene mutations in children with congenital lipoid adrenal hyperplasia

Abstract:

This article reported the clinical manifestations, steroid profiles and adrenal ultrasound findings in two unrelated Chinese girls with lipoid congenital adrenal hyperplasia (LCAH). Direct DNA sequencing and restriction fragment length polymorphism (RFLP) analysis were used to identify the mutations of steroidogenic acute regulatory protein (StAR) gene. The two patients with 46,XX karyotype, presented hyperpigmentation, growth retardation, and hyponatremia. Steroid profiles analysis revealed elevated plasma adrenocorticotrophic hormone levels, decreased or normal serum cortisol levels and low levels of androgens. Ultrasound examinations revealed that enlarged adrenals in patient 1 and normal adrenals in patient 2. Direct DNA sequencing of StAR gene showed a reported homozygous for c.772C>T(p.Q258X) in patient 1. Compound heterozygous for c.367G>A(p.E123K) and IVS4+2T>A (both novel mutations) were found in patient 2, inherited from her mother and father respectively. The amino acid of mutant position of the novel p.E123K was highly conserved in ten different species and was predicted to have impacts on the structure and function of StAR protein by the PolyPhen-2 prediction software. RFLP analysis revealed three bands (670, 423 and 247 bp) in patient 2 and her father and two bands (423 and 247 bp) in her mother and 50 controls. It is concluded that LCAH should be considered in girls with early onset of adrenal insufficiency and that steroid profiles, karyotype analysis, adrenal ultrasound and StAR gene analysis may be helpful for the definite diagnosis of LCAH.