title: First trimester prenatal diagnosis of 21-hydroxylase deficiency by linkage analysis to HLA-DNA probes and by 17-hydroxyprogesterone determination.
abstract: The close genetic linkage between the gene for congenital adrenal hyperplasia due to 21-hydroxylase (21-OH) deficiency and HLA genes allowed us to use the polymorphism of this system as a marker of the disease. HLA genotyping can be performed by using restriction enzyme fragments hybridized with specific probes instead of serologic methods. In seven pregnancies at risk for 21-OH deficiency, a first trimester prenatal diagnosis has been performed by determining the fetal genotype by linkage analysis of DNA from chorionic villi using HLA class I and class II probes. In four of these pregnancies, determination of 17-OH progesterone in first trimester amniotic fluid afforded a complementary approach to the diagnosis.
mesh_terms: D019326:17-alpha-Hydroxyprogesterone; D000312:Adrenal Hyperplasia, Congenital / Q000175:diagnosis*; D002824:Chorionic Villi / Q000032:analysis; D004247:DNA / Q000235:genetics; D004262:DNA Restriction Enzymes; D005260:Female; D005315:Fetal Diseases / Q000175:diagnosis; D008040:Genetic Linkage; D005819:Genetic Markers; D006680:HLA Antigens / Q000235:genetics; D006801:Humans; D006908:Hydroxyprogesterones / Q000032:analysis*; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D011296:Prenatal Diagnosis; D011863:Radioimmunoassay; D013255:Steroid 21-Hydroxylase / Q000235:genetics; D013250:Steroid Hydroxylases / Q000172:deficiency*
chemical_list: D005819:Genetic Markers; D006680:HLA Antigens; D006908:Hydroxyprogesterones; D019326:17-alpha-Hydroxyprogesterone; D004247:DNA; D013250:Steroid Hydroxylases; D013255:Steroid 21-Hydroxylase; D004262:DNA Restriction Enzymes