Congenital adrenal hyperplasia (CAH) is a group of inherited disorders that affect the adrenal glands, which sit above the kidneys and make essential hormones. The most common form, 21-hydroxylase deficiency, affects roughly 1 in 15,000 newborns. It is screened for because the severe (salt-wasting) form can cause a life-threatening adrenal crisis in the first weeks of life, and early detection allows it to be prevented.
What causes CAH
CAH is caused by inherited changes in genes that make enzymes the adrenal glands need to produce cortisol and, in some cases, aldosterone. Most cases result from variants in the CYP21A2 gene. It is inherited in an autosomal recessive pattern, meaning a child inherits a variant from each parent, who are usually unaffected carriers.
How newborn screening detects it
The screen measures a hormone called 17-hydroxyprogesterone (17-OHP) in blood from the heel prick. Levels are elevated in babies with the common form of CAH. Because premature babies can have higher baseline levels, results are interpreted with birth weight and gestational age in mind, and an abnormal result leads to confirmatory testing.
How CAH is treated
CAH is managed with hormone replacement, typically glucocorticoids to replace cortisol and, in the salt-wasting form, mineralocorticoids plus salt supplementation. Treatment is lifelong and adjusted over time, but with early diagnosis and steady management, children with CAH can grow and thrive. Early detection is what prevents a dangerous salt-wasting crisis.
How genetic screening fits in
State newborn screening does an excellent job of catching CAH. Genetic screening looks at the same picture from the DNA level and, in a single test, can also assess the genes tied to more than 1,000 other clinically actionable childhood conditions, many of which are not on any state panel. Fore Genomics offers an at-home cheek-swab screen, sequenced in CLIA-certified and CAP-accredited labs, with results supported by board-certified genetic counselors. See how your state’s panel compares, see what we screen for, or start screening.
Frequently asked questions
Is CAH screened for in every state?
Yes. CAH (21-hydroxylase deficiency) is a core condition on every U.S. state newborn screening panel.
Why is early detection of CAH so important?
The severe salt-wasting form can cause a life-threatening adrenal crisis within the first weeks of life. Screening allows treatment to begin before that happens.
Is CAH inherited?
Yes. CAH is autosomal recessive, so a child inherits a gene variant from each parent, who are typically unaffected carriers.
Medically reviewed by Fore’s Clinical Team. This article is for general educational purposes and is not medical advice. Sources: HRSA Newborn Screening; National Organization for Rare Disorders (NORD).