Abstract: | Five individuals with the asymptomatic, 'non-classical', 'cryptic' form of congenital adrenal hyperplasia (CAH) due to 21-hydroxylase (21-OH) deficiency from 5 unrelated families were discovered during hormonal studies and HLA-typing performed in a series of 24 families with CAH due to 21-OH deficiency. Four of the 5 individuals with the 'cryptic' form of CAH belong to families where the index case was a patient with the classical form of CAH due to 21-OH deficiency. The fifth one originated from a family where the index case was a girl with the 'non-classical', 'late-onset' form of the disease. All the 5 individuals had no clinical symptoms in spite of clearcut biochemical signs of 21-OH deficiency: increased 17-OH-progesterone (17-OHP), dehydroepiandrosterone and androstenedione levels, particularly after ACTH-stimulation. The 17-OHP response upon ACTH stimulation of heterozygotes for this 'non-classical' form of 21-OH deficiency did not differ from the response of heterozygous individuals for the classical form of the disease. The results of this study confirm the hypothesis that individuals with the 'cryptic' form of CAH due to 21-OH deficiency are genetic compounds bearing one allele for the severe, classical form, and on the homologous locus, another one for the mild 'non-classical' form of CAH due to 21-OH deficiency. Their genotype was 21-OH severe/21-OH mild.(ABSTRACT TRUNCATED AT 250 WORDS) |