Overview
Congenital adrenal hyperplasia (CAH) is a group of genetic disorders that affect the adrenal glands, a pair of organs that produce important hormones. CAH occurs when a gene change (mutation) affects the way the body produces the following hormones:
- Cortisol, which regulates the body's response to stress or illness
- Mineralocorticoids, responsible for regulating sodium and potassium levels
- Sex hormones, which are responsible for development in both males and females
There are two major types of congenital adrenal hyperplasia:
- Classic CAH, a severe form that is usually detected during infancy
- Non-classic CAH, a milder form that is more common and may not be identified until late childhood or early adulthood
Symptoms & Diagnosis
Symptoms of classic CAH include:
- Insufficient cortisol
- Atypical genitalia
- Excess male sex hormones
- Altered growth
- Fertility issues
Non-classic CAH presents no symptoms at birth, with some individuals never experiencing any symptoms at all. However, for most people, symptoms are generally present in late childhood or early adulthood and include:
- Irregular menstrual cycles and fertility issues in females
- Females may develop masculine characteristics, such as excessive body hair and a deepening voice
- Severe acne
- Early puberty in both males and females
- A rapid growth rate during childhood and a shorter final height than expected
Prenatal Testing
Diagnostic tests used to identify CAH in fetuses include:
Amniocentesis
Using a needle, amniotic fluid is withdrawn from the womb and examined
Chorionic villus sampling
Cells are withdrawn from the placenta and examined.
Newborns and infants
Many countries recommend routine screening of newborns for genetic 21-hydroxylase deficiency during their first few weeks of life. A lack of 21-hydroxylase identifies the classic form of CAH but does not identify the non-classic form.
Chromosomes can be analyzed to determine genetic sex in female infants with severe atypical genitalia.
A pelvic ultrasound can identify female reproductive structures like the uterus and ovaries.
Children and young adults
Diagnostic tests used to identify CAH in children and young adults include:
History
A previous history of an affected child with adrenal insufficiency or neonatal death is significant for CAH. Parental consanguinity (the fact of being descended from the same ancestor) is an important factor.
Physical exam
A health care provider will examine the child thoroughly, paying special attention to blood pressure, genital appearance and growth parameters.
Blood and urine tests
These tests detect hormone levels outside of the standard range produced by the adrenal glands and also measure electrolyte levels.
Karyotype test
This test will determine the biological sex of the baby.
Genetic testing
A genetic test may be required to diagnose CAH as it identifies the genetic mutation.
Treatment
In some cases of CAH where genital ambiguity is marked, gender assignment can be a challenge and must be managed by experts.
Hormone replacement is essential to suppress the excess male hormone production and ensure a normal growth pattern.
