Carrier status for steroid 21-hydroxylase deficiency is only one factor in the variable phenotype of acne

Previous endocrine studies of women with acne have produced diverse results. This study was designed to seek evidence, from endocrine and genetic studies, for impaired steroid biosynthesis in patients with acne.

Adrenal stimulation tests with synthetic adrenocorticotrophic hormone (ACTH) were performed.

Steroid hormones were measured basally and 30 minutes after ACTH. The results were correlated with analysis of the steroid 21-hydroxylase gene (CYP21).

Fifty-one consecutive female patients (mean age 27.1 years) referred with acne.

The median plasma 17-hydroxyprogesterone (17-OHP) before and 30 minutes after ACTH were 2.5 nmol/l (range 1.1-8.2) and 7.3 (2.1-17.8) nmol/l which were significantly above normal female controls (n = 11, mean age 25.6 years) at 1.5 (0.9-4.2) and 4.6 (2.6-8.4) nmol/l. Eighteen of 51 acne patients showed an abnormal 17-OHP response. The 21-hydroxylase gene (CYP21) was examined for major deletions and for three common point mutations in 31 of the patients (14 with exaggerated 17-OHP response). One patient had a deletion of CYP21 on one allele consistent with carrier status for the classical congenital adrenal hyperplasia (CAH). Five patients, one of whom had a normal 17-OHP response to Synacthen, were heterozygous for the val 281 leu mutation in exon 7 of the CYP21 and were therefore carriers for a mutation associated with late-onset CAH. One patient with a raised 17-OHP response was homozygous for the splice site mutation in intron 2 and one patient with a normal 17-OHP response was heterozygous for the mutation. None of the patients had the ile 172 asn mutation. Eight of the 31 acne patients who had CYP21 gene analysis were carriers for mutations in the 21-hydroxylase gene but only six would have been detected by an abnormal response of 17-OHP on stimulation.

Although alterations of the CYP21 gene were more common in acne than in controls there is a poor correlation between these events and raised steroids and acne. Factors other than mild impairment of CYP21 contribute to the variability of the clinical phenotype in hyperandrogenic states including acne.