Congenital adrenal hyperplasia (CAH) is a group of rare genetic conditions that affects the adrenal glands. These glands make hormones such as cortisol, aldosterone (which helps to regulate salt levels in the body) and androgens (male sex hormones).
Newborns with CAH lack enzymes required to make these hormones, which can result in very low cortisol and salt levels, and dangerously high potassium levels.
CAH can affect a child's normal growth and development, including normal growth of the genitals. If left untreated, newborns can become extremely unwell and may die suddenly in the early weeks of life.
Newborns with CAH are often misdiagnosed, as the presentation of CAH can be attributed to other more common conditions.
Types of congenital adrenal hyperplasia
There are 2 main types of CAH:
Classic CAH – the more severe form, usually noticed during infancy or early childhood. There are 2 types of classic CAH: salt-losing CAH and non-salt losing CAH.
Non-classic CAH or late-onset CAH – the milder form, usually noticed in adolescence or early adulthood (this type of CAH is not screened for as part of the Newborn Bloodspot Program).
Signs and symptoms of congenital adrenal hyperplasia
The effects of CAH vary significantly from person to person, depending on the type of CAH.
Girls with classic CAH can be born with genitals that look more male than female. Other signs and symptoms of classic CAH in infants include:
an enlarged penis for boys
poor weight gain or weight loss
dehydration
vomiting.
Children and adults with either type of CAH can have:
rapid growth and early puberty, followed by shorter than average final height
At any age, people with CAH are vulnerable to an 'adrenal crisis', in which they feel very ill, weak and tired, and start vomiting. An adrenal crisis usually occurs during times of physical stress.
