Book Description

Rheumatic heart disease is an inflammatory heart disease that affects millions of people around the world. Especially high rates of the disease can be found in Oceania, including the island nation of Samoa. Genetic studies of immune response genes have provided insight into a possible genetic link to increased susceptibility to rheumatic heart disease, including the genes that code for the toll-like receptor (TLR) protein family. One of the functions of TLR proteins is to recognize the presence of bacteria via identification of bacterial flagella. My evaluation of a Samoan family identified a variant in the TLR-5 gene that would inhibit this ability. However, further study showed this variant to not be statistically significant in relation to rheumatic heart disease susceptibility. My contribution to a regional genome-wide association study of Oceania resulted in the discovery of a variant in the IGHV4-61 gene affecting the ability of antibodies to properly bind to bacterial antigens. This variant was associated with a 1.4-fold increased risk of rheumatic heart disease development. The success of this study warrants further investigation of the IGHV4-61 variant in other populations and illustrates the benefits of utilizing a genome-wide association study to study rheumatic heart disease.