Early prenatal diagnosis of 21-hydroxylase deficiency using amniotic fluid 17-hydroxyprogesterone determination and DNA probes

The results of early prenatal diagnoses of congenital adrenal hyperplasia are reported. The determination of 17‐hydroxyprogesterone values in amniotic fluid taken transabdominally at 11 weeks of gestation enabled prenatal diagnosis of congenital adrenal hyperplasia due to 21‐hydroxylase (21‐OH) deficiency. There is a clear‐cut difference between normal and pathological values at that time of pregnancy. This method of diagnosis can be combined with genotyping of the fetus by HLA‐DNA probes on chorionic villus sampling or can be used alone. Prenatal diagnosis with a 21‐OH probe is possible when a preliminary study has demonstrated that the index case is homozygous for the deletion.