Allelic heterogeneity refers to the presence of two or more different variations in the same gene that result in a similar disease or trait. In other words, allelic heterogeneity is a genetic condition in which different mutations in the same gene cause the same disease. There are numerous synonyms for the term "allelic heterogeneity," including genetic heterogeneity, locus heterogeneity, nonallelic heterogeneity, genetic locus heterogeneity, and genetic locus heterozygosity. While these terms may have slightly different meanings, they are all used to describe the same underlying condition in which different mutations in the same gene can result in similar outcomes. Understanding the various synonyms for allelic heterogeneity can help researchers better identify and diagnose genetic conditions.