Novel genetic variants of the Serine/Threonine Kinase 11 (Peutz-Jeghers Syndrome) (STK11) gene are described. Various genotypes, haplotypes, and haplotype pairs that exist in the general United States population are disclosed for the STK11 gene. Compositions and methods for haplotyping and/or genotyping the STK11 gene in an individual are also disclosed. Polynucleotides defined by the sequence the haplotypes disclosed herein are also described.
