This information is provided by the National Institutes of Health (NIH) Genetic and Rare Diseases Information Center (GARD).
21-hydroxylase deficiency is the most common cause of congenital adrenal hyperplasia (CAH). CAH is a group of disorders that affect how the adrenal glands work. In 21-hydroxylase deficiency, a missing enzyme leads to overproduction of specific hormones made by the adrenal glands. There are three types of 21-hydroxylase deficiency that vary by the severity of symptoms. Infants with the more severe forms can experience excessive loss of salt in their urine, which can be life-threatening. Female infants may be born with genitalia that doesn’t look male or female (ambiguous genitalia). Children with the less severe forms can have early puberty, excess hair growth, short stature as adults and decreased fertility.
21-hydroxylase deficiency is caused by genetic changes in the CYP21A2 gene and is inherited in an autosomal recessive pattern. Newborn screening is available in all 50 states of the US to test for this disorder at birth. The diagnosis is made based on the clinical symptoms, biochemical and genetic testing. Treatment is available and involves managing the symptoms through steroids and other medications. The long-term outlook for people with 21-hydroxylase deficiency depends on the severity of symptoms and the ability to manage the condition with medications.
For more information, visit GARD.