CYP21A2 and classic congenital adrenal hyperplasia due to 21-hydroxylase deficiency: reported a high incidence of classic 21-OHD in the Romani population in the Republic of North Macedonia and found that 9/10 patients are homozygous for the c.IVS2-13A/C-G variant (14), we decided to estimate the prevalence and genotype of 21-OHD in Croatian Romani and, if high, assess the possible causes and estimate the frequency of particular CYP21A2 pathological variants.