Congenital Adrenal Hyperplasia (CAH)

Causes of CAH are due to chromosome mutations. There are two types of CAH, both due to different enzymes which exist in the person’s chromosome. The first enzyme, enzyme 21-hydroxylase, causes 90% of the disease, and affects both hormones, glucocorticoid and mineralocorticoid. Both of these hormones are secreted from the outer adrenal gland, or adrenal cortex. These persons have the ‘salt-wasting’ form of CAH. They present with low sodium, low blood volume, low blood pressure, and high potassium levels. The second type, is due to enzyme 11-hydroxylase, and only 10% of patients with CAH have this type. These people have an accumulation of metabolites with mineralocorticoid properties which causes high blood pressure. Therefore, simple blood pressure measurements can differentiate the two different types of CAH. The Classic enzyme 11-hydroxylase CAH occurs more frequently in Moroccan Jews, while Non-Classic enzyme 21-hydroxylas CAH occurs most frequently in Ashkenazi Jews, and In Hispanic, Slavic and Italian populations.

CAH is also known as an adrenogenital syndrome because it leads to overproduction of androgen, a form of male sex hormone.

CAH is caused by the lack of an enzyme needed by the adrenal gland to make the major steroid hormones of the adrenal cortex: cortisol and aldosterone. Without these hormones, steroids are 'diverted' to becoming androgens, causing early (or inappropriate) appearance of male characteristics.

Editor's Note:

"Race" is sometimes mentioned as a risk factor in the development of certain cancers and a number of other diseases. When you read this in a discussion about an illness, note that the explanation seldom refers to anything biological. Instead, it usually refers to behavior, such as eating habits. The kinds of behavior usually mentioned as risk factors are culturally determined. They are not genetic or biological.