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Hormone and bone diseases

Congenital adrenal hyperplasia (21-hydroxylase deficiency, CAH)

An inherited disease that affects the adrenal glands. The glands make too little of some hormones and too much male hormone. In the severe type, a dangerous loss of salt and water can occur in infancy.

Included in Türkiye's National Newborn Screening Programme (heel-prick test) since 2022. Source

Orphanet has a guideline for emergency doctors for this disease (language: French, Italian). See on Orphanet

Prepare an emergency card

This page is translated from the Turkish original.

This disease is followed through the “Hormone and bone diseases” group.

Understanding the disease

This section has not yet been reviewed by a physician. It summarises patient information from sources such as MedlinePlus, Orphanet and the NHS in plain language. The disease can differ from person to person; talk to your doctor about diagnosis and treatment.

What happens in this disease?

The adrenal glands make hormones called cortisol and aldosterone. In this disease, an enzyme that makes these hormones is missing. Because of this, too little of the two hormones is made, and too much male hormone. Too little aldosterone can lead to salt loss from the body.

Which symptoms can occur?

There are three types, depending on severity. In the most severe type, there is dangerous loss of salt and water in infancy. In the mildest type, symptoms appear late or not at all.

  • In the first weeks, poor feeding, vomiting, weight loss and fluid loss (in the salt-wasting type)
  • In baby girls, a different appearance of the external genitals (common in severe types)
  • Fast growth in childhood but short adult height (sometimes)
  • Early puberty (sometimes)
  • In women, excess hair growth, irregular periods and acne (sometimes)
  • Fertility problems (sometimes)

How is it diagnosed?

In baby girls, findings seen at birth can raise suspicion. In newborn screening, it can be detected early by measuring a substance called 17-OHP in the blood. The diagnosis is confirmed with blood tests. A genetic test can also be done.

Treatment and care

The main approach is lifelong replacement of the missing hormones. In the salt-wasting type, a hormone that keeps the salt balance is also given. For some girls, surgical options may be discussed. Follow-up is done regularly by a team of different specialists. The doctor who follows the disease decides which treatment is suitable.

For the family: inheritance and genetic counselling

To have the disease, a person must receive one changed gene from the mother and one from the father. Carrier mothers and fathers often have no symptoms. The risk is 1 in 4 in each pregnancy. Options for diagnosis before birth can be discussed in genetic counselling.

Source: MedlinePlus Genetics — 21-hydroxylase deficiency · Orphanet — Classic congenital adrenal hyperplasia due to 21-hydroxylase deficiency (ORPHA:90794)

Key facts

How common is it?
Prevalence: 1-9 per 100 000 (Europe) · Birth prevalence: 1-9 per 100 000 (Worldwide)
How is it inherited?
Autosomal recessive
When does it usually start?
Before birth, Newborn period, Infancy, Childhood, Adolescence, Adulthood
Gene(s) involved
CYP21A2

These facts are taken from Orphanet and MedlinePlus records (last checked: October 7, 2026). Frequency values are approximate ranges.

You are not alone: patient associations in Türkiye

Non-profit patient and family organizations in Türkiye working on this disease or disease group. Links are for information; Doktorclub is not affiliated with these organizations and does not endorse them.

We could not find a patient association specific to this disease.

For all rare diseases: Nadir Hastalıklar Federasyonu

Support and help

Doktorclub does not diagnose, recommend treatments or refer you to hospitals or doctors. These pages are meant to help you talk with your doctor.

News about CAH

Clinical trials (ClinicalTrials.gov)

A clinical trial is a regulated study that tests whether a new treatment is safe and whether it works, in patients who volunteer. Most trials look for a certain age, genetic change and health condition. Taking part is voluntary.

This list is not a treatment recommendation. Treatments tested in phase 1–3 trials are investigational (experimental): their efficacy and safety have not yet been proven and they are not approved treatments. Taking part depends on each trial’s criteria and a physician’s assessment; the first step is to talk to the doctor who manages your care.

Questions you can ask your doctor

  • Could this trial be suitable for us?
  • If we take part, how would current treatment and check-ups be affected?
  • Where does the trial take place, and how are travel and accommodation handled?
  • What happens if we want to leave the trial?

ClinicalTrials.gov lists 14 active interventional studies for this disease. 6 are recruiting now; none has a site in Türkiye. Last checked: October 7, 2026.

Selected records (studies with a site in Türkiye first):

See all studies on ClinicalTrials.gov · Joining clinical trials

Hormone and bone diseases: other news

Medical codes (for talking with your doctor and finding sources)

These codes identify the disease in international classifications and databases. They can help when you talk with your doctor or look for reliable sources.

Orphanet code: ORPHA:90794 · ICD-11 5A71.01

Codes checked against WHO ICD-11 and Orphanet on October 6, 2026.

This page provides general information and does not replace diagnosis or treatment. Talk to your doctor about symptoms, diagnosis and treatment.

The information on these pages is for general information only and does not replace medical advice. Talk to your doctor about diagnosis and treatment decisions. In an emergency in Türkiye, call 112.

Every update is based on an open source and labeled with its level of evidence. No advertising and no drug brand names. Our scientific principles

This page was translated from Turkish by the Doktorclub editorial team.