1. A method for use by a computing device in genetic trait classification involving at least two genes associated with a genetic trait the method comprising the acts of: calculating, by the computing device, a value for classifying an individual into one of a plurality of trait classes associated with the genetic trait based on a summation of: a first sum of contributions associated with each genotype of a plurality of genotypes of the at least two genes identified in the individual, the contributions for each genotype identified at least in part from a calculated statistical value for the genotype from counts of individuals in the sample population associated with each trait class of the genetic trait, and a second sum of contributions associated with each statistically significant genotype combination of one or more genotype combinations of the genotypes identified in the individual, each statistically significant genotype combinations identified in the sample population as having a statistically significant association with one of the trait classes of the genetic trait; and classifying the individual outside of the sample population into one of the plurality of trait classes of the genetic trait based on the calculated value.