Correlation between variants of CYP21A2 gene promoter region and nonclassical 21-hydroxylase deficiency

Abstract

To summarize the clinical characteristics of two children with nonclassical 21 hydroxylase deficiency (NC-21OHD) due to variants of CYP21A2 gene promoter region. Clinical characteristics and the results of genetic testing were reviewed. The main clinical manifestations of the two children included precocious puberty with poor bone age/progression control and menstrual disorder with hirsutism. Patient 1 had compound heterozygous variants for -126C>T, -113G>A, -110T>C and p.I173N; her mother was heterozygous for -126C>T, -113G>A and -110T>C, and her father was heterozygous for p.I173N. Patient 2 had compound heterozygous variants for -126C>T, -113G>A and p.I2G, whose mother was heterozygous for -126C>T and -113G>A, and father was heterozygous for p.I2G. Diagnosis of NC-21OHD should be considered for children with hirsutism, menstrual disorder and poor bone age/progression control. The promoter region of CYP21A2 gene should be analyzed when no variant is detected in its coding regions.