Congenital Adrenal Hyperplasia (CAH)


CAH is an inherited disorder of steroidogenesis with a wide spectrum of expression. In about 95% of cases the condition is the result of 21-hydroxylase deficiency, an autosomal recessive condition mapping to CYP21A2 on chromosome 6p21.3. The incidence of CAH based on biochemical criteria is 1 in 14,000 including the non-classical form; a carrier frequency of 1 in 50 is used for risk calculations.

Referral information

We accept referrals for mutation scanning to confirm a clinical diagnosis in affected patients and/or parents. We offer prenatal diagnosis once the familial mutation(s) are known. This usually follows fetal sexing (which can be offered using conventional or non-invasive prenatal diagnosis – see service profile). In addition we can offer carrier testing in at-risk family members.

Price & reporting times

NHS referrals to this service are paid for where there is an existing specialist commissioning contract for genetic testing. In other cases please contact the lab for prices.

Test Price (NHS) Price (non-NHS) TRT
Common mutation screen POA POA 28 calendar days
Single mutation test POA POA 28 calendar days
Prenatal diagnosis POA POA 3 calendar days
Family testing (index + parents) POA POA 28 calendar days
DNA sequencing (second tier testing) POA POA 56 calendar days

Test validation & quality assurance - information for users

The eight common mutations account for approximately 70% of 21-hydroxylase deficiency mutations in the UK population (estimated following analysis of >600 index cases in-house).

Referral guidelines

Please see our referral guidelines for more information.

OMIM Number(s) - 201910

Gene(s) - CYP21A2