A novel frameshift mutation 840delA and a novel polymorphism D203A in the steroidogenic acute regulatory protein gene in a Japanese patient with congenital lipoid adrenal hyperplasia

Abstract

Congenital lipoid adrenal hyperplasia (CLAH) is an autosomalrecessive disorder characterized by impaired production of allsteroids including glucocorticoids, mineralocorticoids and sexsteroids. It has recently been reported that mutations in thesteroidogenic acute regulatory protein (StAR) gene cause CLAH. We analyzed the StAR gene in a Japanese patient with CLAH. The patient was revealed to be a compound heterozygote bearing a nonsense mutation Q258X, changing codon 258 (CAG) encoding Gln to the stop codon TAG, and a novel frameshift mutation 840delA resulting from deletion of one of the three adenosines normally present in codon 238 (AAA), thus leading to a frameshift after codon 237 (Thr) in the StAR gene. The patient was also revealed to be homozygous for a novel missense point mutation D203A, changing codon 203 (GAC) encoding Asp to GCC encoding Ala in the StAR gene. To elucidate the significance of the D203A mutation, we analyzed the StAR gene sequence in twenty normal subjects, and found that all of them were homozygous for the D203A mutation, indicating that the D203A mutation is an innocent polymorphism. In conclusion, we have identified a novel frameshift mutation 840delA which seems to cause 840delA and the first polymorphism D203A in the human StAR gene. Hum Mutat 11:331, 1998. © 1998 Wiley‐Liss, Inc.

STAR splicing mutations cause the severe phenotype of lipoid congenital adrenal hyperplasia: insights from a novel splice mutation and review of reported cases

“…With one exception, all mutations were present in patients in a homozygote or compound heterozygote state. STAR mutations are mostly missense, nonsense or frameshift mutations . Even a complete deletion of the gene has been reported .…”