by Ann Marie Dwyer

Created on: March 09, 2010

Congenital Adrenal Hyperplasia (CAH) is the most common autosomal recessive genetic disorder. CAH is also called 21-Hydroxylase Deficiency because 95% of all cases of CAH are a result of a deficiency of the 21-hydroxylase enzyme. Mild CAH affects between one in 100-1000, while the most severe CAH only occurs one in every 14,000.

Statistics cannot tell you much about a disease. So, what is CAH?

Congenital

CAH is a genetic disorder which is passed to a child from parents who both have the recessive gene on the sixth chromosome. If both parents have the recessive gene, there is a 25% chance their child will have CAH. Fetuses at risk of CAH can be diagnosed through amniotic fluid analysis or by chorionic villus testing though human leukocyte antigen (HLA) typing. Many states screen newborns for CAH at birth.

Adrenal

The adrenal glands produce hormones, including cortisol, androgens and aldosterone. When the adrenal glands do not function properly because of CAH, a hormonal imbalance results causing the symptoms of CAH.

Hyperplasia

Hyperplasia means overgrowth. Patients with CAH have enlarged adrenal glands. Since the patient lacks the 21-hydroxylase enzyme necessary for the adrenal gland to complete the formation of cortisol and aldosterone, the adrenal gland becomes malformed using the raw materials not used to produce cortisol and aldosterone to overproduce androgens, like testosterone.

Forms of CAH

The most severe form of CAH is salt-wasting CAH. The hormone cortisol regulates the salt content in the body. Dehydration, vomiting, diarrhea, poor weight gain, poor feeding and drowsiness are some of the symptoms which accompany salt-wasting congenital adrenal hyperplasia in infants. A newborn with CAH can die of adrenal shock within 14 days if left untreated.

A milder form is simple virilizing CAH. Simple virilizing CAH is more common than salt-wasting CAH. Physical genitalia ambiguity is lessened in these females than in salt-wasting CAH, but still present to some degree. These CAH children will often have moderate to severe pulmonary and sinus infections, be tall for their age, have severe acne and begin puberty early.

The mildest form of CAH does not appear until later in childhood or at adolescence. Early growth of pubic hair and rapid height growth are the first symptoms of mild CAH.

Symptoms: Physical

Both male and female children are affected by CAH. At birth CAH may be visible in altered genitalia in females. Males may or may not have a discoloration

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