Congenital Adrenal Hyperplasia (CAH)

Congenital adrenal hyperplasia (CAH) is a rare condition inherited at birth in which the body produces too much of a male sex hormone, causing abnormal development. It can be found in both girls and boys.

In girls, the condition causes inappropriate male characteristics to appear. 

Patients can be seen by Texas Children's experts in Pediatric and Adolescent Gynecology.

Causes & Risk Factors

Congenital adrenal hyperplasia is caused by a genetic defect that prevents the body’s adrenal glands from working properly. As a result, the body may produce too much of a male sex hormone known as androgen.

If both parents have congenital adrenal hyperplasia or both are carriers of the genetic mutation that causes the disease, the child is at increased risk of having the condition.

Ashkenazi Jews, Hispanics, Yugoslavs and Eskimos are also more likely to develop this disorder.

Genetic counseling and testing is available for high-risk individuals.

Symptoms & Types

Symptoms may include:

  • Poor weight gain, dehydration, vomiting in infants
  • Abnormal-appearing genitals that look more male than female
  • Irregular or absent periods (amenorrhea)
  • Deep voice
  • Early appearance of pubic and underarm hair
  • Facial hair and excessive body hair
  • Rapid growth during childhood, but shorter than normal as an adult

There are two major types of congenital adrenal hyperplasia:

  • Classic congenital adrenal hyperplasia is a more severe form of the disease, usually found during infancy or early childhood. Untreated, it can lead to a life-threatening "adrenal crisis" with symptoms that include diarrhea, vomiting, dehydration, low blood sugar levels, low sodium levels and shock. An adrenal crisis requires immediate treatment. About 1 in 15,000 children are born with this type of CAH.
  • Nonclassic congenital adrenal hyperplasia is a milder form that usually develops in late childhood or early adulthood. About 1 in every 1,000 children are born with this form of CAH.

Diagnosis & Tests

Because early detection can save lives, a newborn screening test is required in many states, using blood drawn from the heel.

At older ages, diagnosis starts with a detailed medical history and a thorough physical exam.

Additional testing may include:

  • Blood test
  • Urine test
  • X-rays – to determine if bones look older than normal for the child’s age

Treatment & Care

Treatment strategies may include:

  • Medications – to restore the body’s hormones to normal levels
  • Surgery – when needed to correct appearance and function of the genitals
  • Counseling and support
  • Prenatal management – if the condition is diagnosed in the fetus

For infants born with ambiguous external genitalia, blood tests and ultrasounds are used to determine the sex of the child.