SLC19A1 and congenital heart disease: Polymorphisms in folate transporter genes were implicated as risk factors for certain types of birth defects, and recent evidence from human epidemiological studies demonstrated an association between the SLC19A1-A80G polymorphism (rs1051266) and an increased risk for neural tube [37,38], conotruncal heart defects [39,40], and other congenital heart disease [22].