Adrenal hyperplasia is a genetic condition that may affect males or females. It causes the adrenal glands, located just above the kidneys, to produce abnormally high levels of sex hormones--androgens--and cortisol--a stress-related hormone. Dr. Deborah Merke writes in the medical reference UpToDate that a deficiency in the enzyme 21-hydroxylase accounts for over 90 percent of the cases of "classic" adrenal hyperplasia, which is also known as congenital adrenal hyperplasia. Symptoms appear during the first months of life and in early childhood and range from mild to severe.
Ambiguous Genitalia
Baby girls born with a 21-hydroxylase deficiency causing adrenal hyperplasia are born with ambiguous genitalia: the clitoris is greatly enlarged, the labia of the vagina are fused together, and in general, the genital area looks more like that of a baby boy than that of a baby girl. While this may not seem "dangerous", it does present a serious problem--in rare cases, the baby may be assigned the wrong sex and will have to deal with the psychological and physical repercussions of this as she goes through life. As Dr. Merke writes in the UpToDate article "Treatment of classic congenital adrenal hyperplasia due to 21-hydroxylase deficiency in infants and children," a baby born with ambiguous genitalia can be thought of as an emergency for the family--although the baby's life is not in danger, the confusion and indeed trauma of not knowing whether the baby is a boy or a girl can certainly leave a major impact on the family.
Early Puberty and Short Stature
As a result of the abnormally low levels of the enzyme 21-hydroxylase, sex hormones--the androgens referred to above--and cortisol are produced at abnormally high levels. The elevated levels of sex hormones can result in a child reaching puberty earlier than normal, which causes the growth plates in the bones to close early. In addition, the high levels of cortisol also contributes to the short stature by suppressing the growth of children. As a result, a child, whether a girl or a boy, is at risk for an abnormally early puberty and being shorter the she would have been expected if she did not have congenital adrenal hyperplasia.
Adrenal Crisis
One subtype of congenital adrenal hyperplasia is known as salt-losing or salt-wasting. In this subtype, babies are born with low levels of sodium and glucose, and high levels of potassium; they also have low blood pressure. A baby who has these symptoms is said to be in "adrenal crisis" and is need of urgent treatment. Treatment of adrenal crisis includes treatment of the low blood pressure and rehydrating the baby, who will be dehydrated from the loss of the water that accompanies loss of sodium and potassium. Replacing the lost potassium and salt is also important. This is done by giving the baby salt and sugar-fluids intravenously. If the baby's potassium levels are high, she is given glucose and insulin, as these will help decrease the levels of potassium in the blood.
References
- "UpToDate"; Genetics and clinical presentation of classic congenital adrenal hyperplasia due to 21-hydroxylase deficiency; Deborah Merke; October 2009
- "UpToDate"; Treatment of classic congenital adrenal hyperplasia due to 21-hydroxylase deficiency in infants and children; Deborah Merke; April 2008
- Mayo Clinic: Congenital Adrenal Hyperplasia
