Clinical features and molecular genetic analysis of congenital lipoid adrenal hyperplasia caused by steroidogenic acute regulatory protein gene mutation

Abstract

Objective To investigate the clinical and molecular genetic features of neonatal congenital lipoid adrenal hyperplasia (CLAH) caused by mutations in steroidogenic acute regulatory protein (StAR) encoding gene. Methods This study retrospectively analyzed the clinical data of a CLAH neonate admitted to Fujian Provincial Maternity and Children's Hospital, Affiliated Hospital of Fujian Medical University in April 2017. StAR gene was analyzed using high-throughput sequencing and Sanger sequencing. Relevant literature retrieved from databases including China National Knowledge Infrastructure (CNKI), Wanfang and PubMed were reviewed, and the reported cases with relatively complete clinical data and results of serum hormone test and StAR gene mutation analysis were collected. Results The index patient presented with hyperpigmentation and growth retardation soon after birth. Laboratory tests revealed hyponatremia, hyperkalemia, increased serum adrenocorticotrophic hormone (263.4 pmol/L) and decreased 17-hydroxyprogesterone (0.16 ng/ml), dehydroepiandrosterone (<0.95 μmol/L), androstenedione (<1.0 nmol/L), testosterone (<0.025 ng/ml), progesterone (0.02 ng/ml) and cortisol (1.6 μg/ml). High-throughput sequencing showed that the patient carried a compound heterozygous mutation of p.Thr240fs in exon 6 and p.Gln258X in exon 7, inherited from the father and mother, respectively. Sanger sequencing confirmed the diagnosis of CLAH caused by StAR gene mutation. After steroid replacement therapy, the patient's symptoms resolved and the concentrations of electrolytes returned to normal. The neonate was followed up to two years of age and no abnormality was found in physical or neurological development. Two Chinese and 11 English publications were retrieved and altogether 96 cases of neonatal CLAH, including the index one, were reviewed and 42 of them had detailed clinical data. The most common clinical manifestations were skin pigmentation (85.7%, 36/42). Other manifestations included vomiting (35.7%, 15/42) and growth retardation (14.3%, 6/42). All patients with physical examination records had female external genitalia (100.0%, 35/35). The common laboratory abnormalities included hyponatremia (95.2%, 40/42), hyperkalemia (88.1%, 37/42), elevated serum adrenocorticotrophic hormone (100.0%, 37/37) and decreased 17-hydroxyprogesterone (90.5%, 19/21), cortisol (86.2%, 25/29), testosterone (9/10) and dehydroepiandrosterone (14/14). p.Gln258X was the most common StAR gene mutation in neonates in Eastern Asia, including China. Most cases had a good prognosis after appropriate steroid replacement. Conclusions CLAH should be considered for neonates with adrenocortical hypofunction, especially with female phenotypes and low 17-hydroxyprogesterone. Karyotyping and StAR gene analysis may be helpful in diagnosis. Timely and appropriate treatment could improve the prognosis. Key words: Adrenal hyperplasia, congenital; 46, XY Disorders of sex development; Phosphoproteins; Mutation; Infant, newborn