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.