ESPE Abstracts

Context: Congenital adrenal hyperplasia (CAH) is a rare genetic defect. Its prevalence is estimated at one case per 3,000 births in Algeria and one case per 15,000 births worldwide. The most common form is due to 21-hydroxylase deficiency associated with mutations in the 21-hydroxylase gene, which is located at chromosome 6p21. Molecular defects of CYP21A2 systematically decrease the activity of this enzyme and result in expression of varying severity and phenotypes. Unfortunately, the search for the genetic anomaly of CAH is not carried out in Algeria.

Goal: Describe the clinical, biological and genetic characteristics of a population of children followed for CAH in the Endocrinology department of the army central hospital in Algiers between 2007 and 2021.

Methods: The study included 26 patients (13 boys and 13 girls) aged 2 to 31 years, followed for CAH. Clinical data from the neonatal period and at the first consultation have been described. The results of the initial biological assessment have been specified (17OHP, Cortisol, ACTH). The genetic study was done in 18 patients with a complete characterization of CYP21A2 mutations.

Results: The diagnosis of CAH was made at birth in 11 of our patients, and during the first 2 months in 8 patients. Four children at the age of 4. The other 3 patients between 11 and 14 years old. Four out of 13 girls have Prader 4 male virilsation, Girl exhibited Prader 5 full male virilization Seventeen of the 28 patients presented the classic form with loss of salt. The most frequent genetic defect was the IVS2-13A/C> G mutation which is found in 9/18 children (50%), 7/9 of the patients presented with a classic form with loss of salt. The p.I172N mutation was found in 4 children (22%) in the heterozygous state, and all presented a simple virilizing form. A rare mutation p.Q41Afs * 39 was found in one case: a girl who presented a biological profile of an 11 beta hydroxylase.

Conclusion: The frequency of the underlying mutations in our patients, with the classical form of CAH, varied but were quite similar to those reported in the Mediterranean region. Therefore, identifying CYP21A2 abnormalities in Algerian patients and comparing them with incidence and severity in different populations will create a valuable diagnostic tool for genetic counseling.

Key Words: CAH, virilization, CYP21A2, 21-hyrdroxylase deficiency, salt wasting.