In this study, we showed that noninvasive prenatal testing (NIPT) of fetal 21-OHD can be accomplished by analyzing a 274.15 kb targeted region, including CYP21A2 and 1607 surrounding highly heterozygous SNPs distributed within 2 Mbp chromosome 6 region. The gene discussed is CYP21A2; the disease is classic congenital adrenal hyperplasia due to 21-hydroxylase deficiency.