SAT-LB049 Identification of a Rare Mutation in Congenital Adrenal Hyperplasia Patients in Costa Rica

Abstract: Congenital adrenal hyperplasia (CAH) is a group of enzymatic defects in cortisol biosynthesis. Steroid 21-hydroxylase deficiency accounts for greater than 90% of cases. Newborn screening has allowed for early detection of cases and currently, molecular analysis can identify the genotypes of these patients. Phenotype-genotype correlation has been well described in previous studies. In Costa Rica, there is no data about the genetic background of these patients, nor their phenotypic correlation. Design: observational, retrospective, descriptive study based on review of patient files who had a diagnosis of CAH and were performed molecular analysis using gene sequencing or MLPA during the period from 2006 to 2018 (N=58). Objective: to describe the clinical and genetic characteristics of CAH patients due to 21-hydroxylase deficiency in Costa Rica. Results: 53.4% (31/58) of the patients were males and 80.4% (37/46) were born full term; 72.4% (42/58) had salt wasting phenotype, 8.6% (5/58) simple virilizing phenotype and 19.0% (11/58) non-classic phenotype. The most frequent genotypes were c.292+5G>A homo in 22.4% (13/58) of patients and Del/Del in 20.7% (12/58). Conclusions: The most frequent mutation in our study population was the c.292+5G>A, which was found in 13/58 patients. This rare variant has only been reported in other three studies so far but as an infrequent mutation in CAH patients (1,2,3). The genetic characteristics of Costa Rican patients differ from what has been documented worldwide and could respond to a founder effect. Reference: (1) Friaes et al., Molecular Genetics and Metabolism. 2006;88:58-65. (2) Ezquieta et al., Prenat Diagn. 2010;30:758-763. (3) Marino et al., Clinical Endocrinology. 2011;75:427-435. Disclosure: All authors have nothing to disclose. Sources of Research Support: no financial support was used for this study, it was financed entirely by the authors. A donation for the statistical work was granted by the National Association for the Study of Diabetes, Endocrinology and Metabolism of Costa Rica (ANPEDEM). Unless otherwise noted, all abstracts presented at ENDO are embargoed until the date and time of presentation. For oral presentations, the abstracts are embargoed until the session begins. Abstracts presented at a news conference are embargoed until the date and time of the news conference. The Endocrine Society reserves the right to lift the embargo on specific abstracts that are selected for promotion prior to or during ENDO.