Congenital adrenal hyperplasia is an abnormality of the adrenal glands that can alter the development of the genital organs. What are the symptoms ? The causes and the consequences? Explanations with Dr. Isabelle Flechtner, pediatric endocrinologist in Paris.
Definition: what is congenital adrenal hyperplasia?
Congenital adrenal hyperplasia (CAH) is a rare genetic disease which is characterized by an anomaly of adrenal glandslocated above the kidneys: some hormones are overproduced, while others are underproduced. This abnormal production of hormones affects the growth and development of the sexual organs. “It exists several forms congenital adrenal hyperplasia depending on the severity of the disease. Classic congenital adrenal hyperplasia accounts for more than 90% of cases. She is related to a deficiency of the enzyme 21 hydroxylase which causes cortisol deficiency and excess androgens. It is the most severe form of the disease. Congenital adrenal hyperplasia is said to be non-classic when it is more moderate and detected later in childhood or in adolescence or even in adulthood.“, explains Dr. Isabelle Flechtner.
What causes congenital adrenal hyperplasia?
Congenital adrenal hyperplasia (CAH) is caused by a deficiency of steroidogenesis enzymes, process responsible for ensuring the production of certain hormones and regulating various body functions such as the growth and development of the sexual organs. This disorder leads to the excessive production of certain hormones and the deficit of others. “It’s a hereditary disease : both parents have only one diseased gene but if the child inherits both diseased genes, he will develop the disease. Depending on the mutations, the child will have a classical or non-classical form. In a classic form, two severe mutations are observed: each of the two parents carries a mutation which has no enzymatic activity. But the most frequent are so-called non-severe mutations which are manifested by acne or body hair early on in little girls or boys. The classical form concerns 1 in 10,000 children and affects both sexes equally. With each pregnancy, there is a 1 in 4 chance that children will inherit both mutations.”details the pediatric endocrinologist.
What are the symptoms of congenital adrenal hyperplasia?
In its classic form, congenital adrenal hyperplasia results in an abnormality of the genital organs in the little girl but no signs in the boy, which is why there is systematic screening at birth. After a few days of life, it can manifest as a dehydration very severe and profound hypoglycemia. Non-classic forms can remain asymptomatic for a long time and then manifest later in childhood or adolescence with early hairiness, given the hormones present in the body. “The excess of testosterone also has an impact on growth: children grow faster but stop growing sooner. They therefore tend to be smaller than averagee. These children benefit from very close follow-up in endocrinology. A treatment to block puberty may be administered to them in the event of early puberty“, specifies the specialist.
The classic (severe) form is systematically detected from birth, on the third day of life, by taking a few drops of blood. A virilization of the external genital organs is observed in the little girl, with in particular an enlarged clitoris that is larger than normal. The labia majora can also look like pouches that hide the entrance to the vagina. In the little boy, on the other hand, the genital organs are normal. At the third week of life usually occurs dehydration correlated with a loss of sodium in the blood which leads to a decrease in blood pressure. The non-classical form is detected later in childhood or adolescence, when faced with early hair growth and accelerated growth.
What are the consequences of congenital adrenal hyperplasia?
“Congenital adrenal hyperplasia can cause severe dehydration in infants can lead to death, a hypoglycemia deep et female genital abnormality. During childhood and adolescence, growth disturbances may occur, as well asprecocious puberty“, says Dr. Isabelle Flechtner.
What is the treatment for congenital adrenal hyperplasia?
“There is no cure but hormone replacement therapy which makes it possible to compensate for the missing hormones (cortisol and aldosterone) and to reduce the production of hormones produced in excess (androgens)”, inform the expert. It consists ofhydrocortisone and fludrocortisone and is administered in tablet form. This treatment should be taken for life. In case of precocious puberty, a treatment blocking the production of hormones by the ovaries and testes can be administered.
When to consider an operation?
Surgery may be offered to correct genital abnormalities present in the little girl. It mainly aims to reduce the size of the clitoris and reconstruct a vaginal orifice that would be obstructed. “Previously, little girls whose appearance of the vulva was abnormal were operated on between the ages of 3 and 6 months. Now it’s more complicated because there is a lot of controversy over the fact that we operated on children who are now claiming the right to be different.“, comments the pediatric endocrinologist.
Thanks to Dr Isabelle Flechtner, pediatric endocrinologist in Paris