Describe the differences between allelic heterogeneity and locus heterogeneity Solution Ans.) The differences between allelic heterogeneity and locus heterogeneity In general terms, allelic heterogeneity defines the different mutation in the same gene locus that displays different phenotype. The variation occur due to natural selection as a consequence of genetic drift, mutation etc. The genetic or locus heterogeneity is the single trait that caused due to mutation in different gene loci. Only a single mutant locus is needed to display the phenotype. Allelic heterogeneity is the mutation in same loci that showed different phenotypic character whereas locus heterogeneity is the only one trait occurs due to mutation in different loci..