Congenital adrenal hyperplasia (CAH)  is caused by inherited defects in steroid biosynthesis, in particular 21-hydroxylase
Mapping of a de novo unequal crossover causing a deletion of the steroid 21-hydroxylase
(CYP21A2) gene and a non-functional hybrid tenascin-X (TNXB) gene.
How a patient homozygous for a 30-kb deletion of the C4-CYP21 genomic region can have a nonclassic form of 21-hydroxylase
Total ion chromatograms of a sample from a healthy female patient and females with suspected 21-hydroxylase
and 3b-hydroxysteroid dehydrogenase deficiencies are shown in Fig.
Mutational spectrum of the steroid 21-hydroxylase
gene in Sweden: implications for genetic diagnosis and association with disease manifestation.
On the other hand, gross gene deletions of the ~30-kb genome, which leave behind the C4A and a single CYP21A-like gene, have been reported to occur in 20% of alleles in patients with CAH involving a 21-hydroxylase
The clinical and biochemical spectrum of congenital adrenal hyperplasia secondary to 21-hydroxylase
deficiency is seen in most CAH patients, while 11[beta]-hydroxylase deficiency is seen in only 5% of CAH patients.
Unilateral testicular enlargement resulting from inapparent 21-hydroxylase
Classic congenital adrenal hyperplasia (CAH) due to 21-hydroxylase
deficiency is rare, occurring approximately once in every 15 000 live births.
LISBON -- Women who receive long-term glucocorticoid treatment for congenital adrenal hyperplasia due to 21-hydroxylase
deficiency are at risk for decreased bone mineral density, Jeremy A.
It is most often caused by deficiency of a specific enzyme, 21-hydroxylase