MTRR gene variants may predispose to the risk of Congenital Heart Disease in Down syndrome patients of Indian origin

Abstract

Background: Down syndrome (DS), also called as trisomy 21, is one of the most leading cause of intellectual disability. DS is associated with a number of phenotypes including Congenital Heart Disease (CHD), Leukemia, Alzheimer’s disease, Hirschsprung’s disease and others. DS affects about 1 in 700 live births.

Objectives: The study aims to investigate the association of MTRR (Methionine synthase reductase) gene polymorphisms (C524T and A66G) with the risk of CHD in DS patients.

Methods: PCR and PCR-RFLP methods were used for the genotyping of study samples and results were validated using Sanger’s sequencing.

Results: MTRR C524T and A66G were significantly associated with the increased risk of CHD in DS. We have also reported two novel polymorphisms, T19775C and 19778_19778delG, in DS with CHD cases with a frequency of 93% and 40%, respectively. These two polymorphisms were not found among DS without CHD group.

Conclusion: Results from this study indicate that the MTRR C524T and A66G polymorphisms influence the risk of the occurrence of CHD in DS patients of Indian Origin. This is the first report from India highlighting the potential association of MTRR C524T and A66G polymorphisms with CHD in DS. We are also the first one to report two novel polymorphisms, T19775C and 19778_19778delG in DS with CHD group. Hence these four polymorphisms can be used to evaluate the risk of CHD in DS patients.

Keywords: Down syndrome; Congenital heart defects or disease; MTRR