Endocrine Abstracts

Targets such as the ‘18 week wait’ may help reduce diagnostic and treatment delay. However, we report two cases of supposed non-classic congenital adrenal hyperplasia (CAH) that perhaps highlight the benefit of time and hindsight as diagnostic tools.

Case 1 A previously unknown 61-year-old contacted our department requesting alternatives to biphosphonate therapy. ‘Mild’ CAH had been diagnosed in 1974 on the basis of elevated urinary 17-oxosteroids (a standard assay at the time) in the presence of hirsutism and oligomenorrhoea. At review she had an un-recordable 17-hydroxy progesterone (17OHP), testosterone and androstenedione. Her prednisolone (7.5 mg) was reduced to 2.5 mg. A short synacthen test (SST) demonstrated a 60 min cortisol of 621 nmol/l with a 17OHP of 4.5 nmol/l. Prednisolone was stopped and subsequent SST demonstrated a 60 min cortisol of 951 nmol/l with a 17OHP of 6.9 nmol/l, thus effectively excluding a diagnosis of non-classic CAH. Genetic testing for 21-hydroxylase abnormalities was negative.

Case 2 A 58 year old lady attended having been diagnosed with non-classical CAH in 1981 on the basis of a single elevated 17OHP (122 nmol/l) (RR<14.0 nmol/l) with subsequent prednisolone treatment. Review revealed hypertension, type 2 diabetes, unrecordable 17OHP, androstendione and testosterone. Prednisolone was reduced and a SST demonstrated a 60 min cortisol of 732 nmol/l with a 17OHP of 12.4 nmol/l. Non-classic CAH was deemed unlikely and prednisolone withdrawn.

Discussion: These cases highlight the need for reviewing the original diagnosis when subsequent biochemical tests are inconsistent. The most definitive hormonal diagnostic test for non-classic CAH is the 17OHP response to synacthen. Of 17-oxosteroid assays were prone to drug interference, including psychotropic drugs such as those taken by case 1. In fairness to our colleagues it was 1979 before specific hormonal and genetic criteria and 1986 before the gene for non-classic CAH were reported.