Genetic heterogeneity

Genetic heterogeneity is a phenomenon in which a single phenotype or genetic disorder may be caused by any one of a multiple number of alleles or non-allele (locus) mutations. This is in contrast to pleiotropy, where a single gene may cause multiple phenotypic expressions or disorders. Genetic heterogeneity describes genetic variation from the normal population. Clinically, genetic heterogeneity refers to diseases that result from multiple gene abnormalities. Multiple gene abnormalities are seen in disorders such as autism, cystic fibrosis, and retinitis pigmentosa.