ESPE Abstracts (2022) 95 P1-210

ESPE2022 Poster Category 1 Adrenals and HPA Axis (52 abstracts)

Congenital Adrenal Hyperplasia due to 21-hydroxylase deficiency: the correlation of 17-hydroxyprogesterone stimulated concentrations with genotype for the identification of the molecular defect- A study of 526 cases

Irene Fylaktou , Anny Mertzanian , Evangelia Charmandari , Christina Kanaka-Gantenbein & Amalia Sertedaki

Division of Endocrinology, Diabetes and Metabolism, Center for Rare Paediatric Endocrine Diseases, First Department of Pediatrics, Medical School, National and Kapodistrian University of Athens, Athens, Greece

Introduction: Congenital adrenal hyperplasia (CAH) is an autosomal recessive disorder caused by impairment of one of the enzymes involved in the steroidogenesis pathway. CAH due to 21-hydroxylase deficiency (21-OHD) is attributed to mutations of the CYP21A2 gene and is distinguished into classic [salt wasting (SW), simple virilizing (SV)] and non-classic form. Herein we present a) the genetic investigation of 526 subjects with suspicion of 21-OHD in the last four years and b) the correlation of 17-hydroxyprogesterone (17-OHP) concentrations after ACTH stimulation test in heterozygotes and genotypically negative individuals.

Patients and Methods: 526 subjects (75% girls, 25% boys) with a mean age of 9 years (3 days-77 years) were referred for genetic analysis of the CYP21A2 gene. The majority of referrals were due to premature adrenarche. Sanger sequencing CYP21A2 gene was carried out in all individuals (and parents when available). MLPA analysis was also performed when duplication/deletion was suspected. A total of 950 parents were analyzed. Two different approaches were applied for the correlation of 17-OHP concentrations, i. Difference 17-OHP(60΄) – 17-OHP(0΄) and ii. Sum 17-OHP(30΄)+17-OHP(60΄) with genotype.

Results: Genetic diagnosis of CAH was achieved in 30% of cases (22% compound heterozygotes and 7.8% homozygotes). 37% of the referrals were found to be heterozygotes (16% heterozygotes for a classic and 84% for a non-classic CYP21A2 mutation). 2.5% harbored a CYP21A2 duplication. No mutation was identified in 31% of the cases. Genotyping of the parents identified 29/950 (3%) compound heterozygotes/homozygotes for the non-classic form of 21-OHD. Table 1 presents the % of the cases where genotype correlates with the 17-OHP values. It should be stated that the best correlation of 17-OHP concentrations and genotype is provided by the p.P30L (94.1%) while the c.*13G>A shows a poor correlation with 17-OHP concentrations (60%) for both approaches tested.

Table 1 Correlations between genotype and stimulated 17-OHP concentrations
Genotype Number 17-OHP(60΄)-17-OHP(0΄) Cut-off for heterozygotes >3.6ng/μL 17-OHP(60΄)+17-OHP(30΄) Cut-off for heterozygotes >10.1ng/μL
p.P30L/Ν 17 16 (94.1%) 16 (94.1%)
p.V281L/Ν 55 44 (80%) 49 (89.1%)
p.P453S/Ν 19 16 (84.2%) 16 (84.2%)
c.*13G>A/Ν 15 9 (60%) 9 (60%)
Ν/Ν 123 77 (62.6%) 46 (37.4%)

Discussion: The two different approaches for the correlation of stimulated 17-OHP concentrations and genotype cannot successfully distinguish the heterozygotes and the genotypically negative examined individuals highlighting the importance of molecular genetic analysis in order to confirm the clinical diagnosis, patient prognosis and genetic counselling.

Volume 95

60th Annual ESPE (ESPE 2022)

Rome, Italy
15 Sep 2022 - 17 Sep 2022

European Society for Paediatric Endocrinology 

Browse other volumes

Article tools

My recent searches

No recent searches.