Background: The usefulness of corticotrophin (ACTH) test in diagnosis of 21-hydroxylase deficiency and/or other enzymic defects in children and adolescents with serum levels of 17-OHP (before 2000 h) >2 ng/ml is known.
Objective and hypotheses: To evaluate the usefulness of ACTH test in diagnosis of non-classical congenital adrenal hyperplasia (NCCAH) and heterozygosity of CYP21 gene molecular defects in children and adolescents with clinical hyperandrogenism and basal 17-OHP<2 ng/ml.
Method: Data of ACTH test from 70 boys and 294 girls aged 0.219.5 years with basal levels of 17-OHP higher than the upper normal range for their age, but <2 ng/ml, were retrospectively analyzed. They were 332 children (mean age: 7.6±2.1 years) with clinical signs of androgen excess (clitoromegalia, hyperpigmentation of external genitalia, advanced bone age, early growth of pubic or axillary hair, increased axillary body odor, acne, before the age of 8 years) and 32 adolescents (mean age: 14.7±1.8 years) with hirsutism, intense acne and/or abnormal menses. The possibility of heterozygosity was evaluated from the 17 OHP nomogram in combination with the criterion of the sum of basal and 60 min 17OHP values >4.9 ng/ml.
Results: Seven cases (1.92%) with NCCAH (60 min 17 OHP levels >16.8 ng/ml, confirmed by genotyping), one of them in adolescence, and 110 (30.2%) of possible heterozygozity, nine of them in adolescence, were detected. The rest of them had normal response. Basal 17OP values differed significantly among NCAH, heterozygotes and normal children (1.93 ng/ml (0.4) vs 1.28 ng/ml (0.4) vs 0.93 ng/ml (0.3), P=0.000). Stimulated 17OHP levels were higher in possible heterozygotes than in normal subjects (5.7 ng/ml (2.5) vs 2.5 ng/ml (0.7) P=0.000).
Conclusion: It is confirmed that in a small number of subjects with NCCAH, basal 17OHP levels can be <2 ng/ml. The clinical significance of heterozygosity detection is not clear, however its value in genetic counseling is obvious.
10 - 12 Sep 2016
European Society for Paediatric Endocrinology