Novel genetic variants of the Electron-Transfer-Flavoprotein, Beta Polypeptide (ETFB) gene are described. Various genotypes, haplotypes, and haplotype pairs that exist in the general United States population are disclosed for the ETFB gene. Compositions and methods for haplotyping and/or genotyping the ETFB gene in an individual are also disclosed. Polynucleotides defined by the haplotypes disclosed herein are also described.
