Congenital Adrenal Hyperplasia (CAH)
Congenital Adrenal Hyperplasia is a group of inherited conditions, present at birth. CAH is a genetic cause of primary adrenal insufficiency, where the production of both cortisol and aldosterone from the adrenal gland, sitting above the kidney, is affected.
In children, CAH is the leading cause of primary adrenal insufficiency, whereas in adults, autoimmune Addison's disease is the leading cause.
Cause of CAH and incidence
CAH is an inherited disorder that is passed on from parent to child. Usually, both parents will be carriers of the disease (each having the same fault in a particular gene) as most types are 'autosomal recessive disorders'. Occasionally, CAH is caused by a change in a gene (a mutation), which may result in different symptoms, depending on which hormones are affected.
The faulty or missing gene causes an enzyme (protein) deficiency that prevents the adrenal gland from making enough of the essential hormones. Recognising these hormone levels are low, the pituitary gland in the brain sends a signal to the adrenal gland to try and increase production (a hormone called ACTH (Adrenocorticotropic hormone). This can't increase cortisol and aldosterone production but does result in an increase in the size of the adrenal cortex (hyperplasia) and the over-production of androgens (steroid sex hormones, including testosterone).
CAH occurs approximately once in every 15,000 people worldwide.
Signs and symptoms
There are many different grades of severity of CAH which will affect the signs and symptoms, and when they start.
In the main 3 types of CAH ('salt-wasting', 'non-salt wasting' and 'late onset'), the production of both cortisol and aldosterone is low, resulting in some similar symptoms to someone with a diagnosis of Addison's disease, another form of primary adrenal insufficiency.) Testosterone production from the adrenal cortex (the outer layer of the adrenal gland) is also affected (increased) in people with CAH, which can cause differences in early sexual development in both boys and girls.
People with CAH are at risk of a life-threatening adrenal crisis and must follow Sick Day Rules.
Treatment
Once a child with CAH has been stabilised after birth, they must follow a cortisol and aldosterone replacement medication regimen. Cortisol replacement is time-critical, as with all types of adrenal insufficiency, and the person is steroid-dependent.
Depending on other symptoms experienced, they may also receive care from genitourinary system specialists (urologists). Due to the complexity of the condition during childhood, it is important that, as well as support from endocrinologists and urologists, support with mental health and emotional wellbeing is available.
Further information and support
Living with CAH is a UK charity run by people who, between them, have been living with CAH for over 100 years! They have been providing support to people living with CAH, as well as raising awareness of the condition, since 1991.
Please note that whilst CAH results in primary adrenal insufficiency, and so the information on our website around medication and treatment of adrenal insufficiency will also be relevant, the ADSHG are not experts in providing information or support in relation to other signs and symptoms experienced with CAH, and so would recommend you fully explore the Living with CAH website.
Get more information from Living with CAH
