ESPE Abstracts

Background: Diagnosis of polycystic ovary syndrome (PCOS) in the adolescent is difficult due to high background rate of menstrual irregularity, high prevalence of polycystic morphology and hyper and rogenic features in this population. Also late onset congenital adrenal hyperplasia (LOCAH) mimics PCOS in this period. It is important to distinguish these entities because of the differences in their therapy. The study aimed to find out the frequency of LOCAH in patients who diagnosed as PCOS by using CYP21A2 genetic analysis.

Objectives and hypotheses: 66 patients who admitted to our clinics and prediagnosed as PCOS were evaluated. Following basal hormonal evaluation, all subjects underwent ACTH stimulating test and CYP21A2 genetic mutation analyse. Patients were divided into three diagnosis groups The patients who diagnosed as LOCAH by genetic analysis were group A. Patients who had peak 17-OHP levels above 6 ng/ml on ACTH stimulation test were group B. And the others were group C.

Results: CYP21A2 genetic mutations were found in 15 (22.7%) patients (Group A). The most common mutations were isolated as Q318× (10.6%) and V281L (9.1%) heterozygous mutations (Table 1). In one patient there was a compound heterozygous mutation (V281L-I172N). In another patient three mutations were found together (V281L-Q318X-I172N). On ACTH stimulation test only 5 (7.6%) of all PCOS patients had 17-OHP levels above 6 ng/ml indicated 21 hydroxylase deficiency (Group B). In three of them, CYP21A2 mutations were also isolated (Table 2). Median (min-max) peak 17-OHP leves were 3.21 ng/ml (0.45–71.30) in group A, 7.87 ng/ml (6.68–71.30) in group B and 2.61 ng/ml (1.08–5.40) in group C. The difference between three groups is statistically significant (P=0.001, Kruskal–Wallis). This difference was based on group B (mWU). For the correct diagnosis of LOCAH according to the genetic analysis was calculated to be superior to ACTH stimulation test (OR:6.12, CI: 0.91–40.84).

Conclusions: In the lights of these findings, in adolescents with PCOS, ACTH stimulation test could not be adequate for differential diagnosis of LOCAH. For exact diagnosis CYP21A2 genetic mutation analysis should also be performed.