Screening for genetic mutations of LDLR gene in Mongolian population with familial hypercholesterolemia

Abstract

Introduction: The third national STEPS survey in 2013 of non-communicable diseases reported that the prevalence of hypercholesterolemia among Mongolian adult population was 61.9%. We chose to study familial hypercholesterolemia because there is no research data about familial hypercholesterolemia in Mongolia. Purpose: The aim of this study was to assess LDLR (low density lipoprotein receptor) gene mutation in patients with familial hypercholesterolemia. Materials and methods: This cross-sectional study included 89 subjects aged between 20 -64, suspected with a clinical diagnosis of familial hypercholesterolemia. Clinical diagnosis of familial hypercholesterolemia was based on Dutch Lipid Clinic Network diagnostic criteria. Possible and probable familial hypercholesterolemia were defined as a total score was 3-5 and 6-8 points. Five ml of venous blood samples were collected from all the subjects and used for biochemical and genetic analysis. DNA was isolated from peripheral blood samples and precise primers were designed for LDLR gene which includes 18 exons. PCR was followed by DNA sequence analysis. Results: A total of 89 subjects included in the study. There were 32(36%) men and 57 (64%) women. The mean age of the participants was 46.5 7.8 years. Mutations in LDLR gene were detected in 3.4% of participants with clinical diagnosis of familial hypercholesterolemia. We found the following 3 LDLR mutations: S265R mutation in Exon-6, C308Y mutation Exon-8 and V502M mutation in Exon-10. Conclusion: This was the first study to identify genetic mutations in LDLR gene in Mongolia. We conclude that screening of family hypercholesterolemia among the Mongolian population is very important to identify individuals who are prone to develop the atherosclerotic cardiovascular disease.