Characterization of the CYP21A2 Gene Mutations in Children with Classic Congenital Adrenal Hyperplasia

Clinical and genetic insights into congenital lipoid adrenal hyperplasia: a case series from a tertiary care center in North India

OBJECTIVES

To describe the clinical and genetic profiles of eight patients diagnosed with Congenital Lipoid Adrenal Hyperplasia (CLAH) at a tertiary center in North India.

METHODS

A retrospective analysis of eight children with genetically confirmed CLAH diagnosed between January 2020 and June 2024 was conducted. Data on clinical presentation, anthropometry, biochemical parameters, genetic mutations, and treatment were reviewed.

RESULTS

Seven patients exhibited the nonclassical phenotype, while one had the classical form. The median (IQR) age at symptom onset, presentation, and diagnosis was 2.50 (1.25-3.82) years, 5.40 (1.70-8.37) years, and 6.31 (4.20-9.12) years, respectively. Skin hyperpigmentation was observed in 100 % of patients, failure to thrive in 75 %, dehydration in 50 %, seizures in 62.5 %, and hypotension in 25 %. Biochemical abnormalities included hyponatremia and hypoglycemia in 62.5 % each, and hyperkalemia in 37.5 % of cases. Genetic analysis identified missense variants in the STAR gene, with six patients carrying the p.Arg188Cys variant, suggesting a founder effect. All patients received glucocorticoid and mineralocorticoid replacement. None of the patients had genital ambiguity or hypogonadism.

CONCLUSIONS

Nonclassical CLAH appears to be more prevalent in the Indian population than previously recognized. Genetic testing facilitates accurate diagnosis and management in resource-limited settings. Lifelong follow-up is essential for monitoring pubertal and gonadal function.

Assessment of Long-Read Sequencing-Based Congenital Adrenal Hyperplasia Genotyping Assay for Newborns in Fujian, China

Long-read sequencing (LRS) provides comprehensive genetic information, but research of LRS applied to congenital adrenal hyperplasia (CAH) newborn screening is limited. This study aimed to evaluate the clinical utility of LRS in genetic diagnosis and second-tier newborn screening. Neonates born between January 2017 and December 2022 in Fujian, China, were recruited for biochemical and LRS-based genetic screening assay. The LRS covers the entire gene regions and exon-intron boundary regions for CYP21A2, CYP11B1, CYP17A1, HSD3B2, and StAR. In this retrospective study, 1,774,555 newborns received 17α-OHP screening, yielding a screening positive rate of 0.20%. Of these high-risk neonates, 3411 were successfully recalled for re-evaluation. Finally, 66 neonates were diagnosed with CAH, with a positive predictive value of 28.82%. Based on this data, the overall prevalence of CAH in Fujian was estimated to be 1:26,883. LRS was performed on 57 neonates with 21-hydroxylase deficiency (21-OHD) and 109 variant alleles were identified. The c.293-13C>G variant (31.19%) was the most prevalent in Fujian. Additionally, 647 neonates with suspected positive results were genotyped, and 41 were identified as carriers, with carrier frequencies of 1:18 for CYP21A2, 1:162 for HSD3B2, and 1:324 for CYP17A1 in Xiamen. Therefore, LRS can provide comprehensive genotypes in approximately 1.5 days at a cost of less than $20 USD per sample, and effectively improve screening efficiency, reduce anxiety of parents during newborn screening (NBS), and shorten the time to referral of CAH patients (approximately 10 days). Such a combined screening strategy is worthy to be recommended for NBS programs in the future.