An allele is a variant form of a gene, which can differ at a single position through single nucleotide polymorphisms or have insertions and deletions. An individual inherits two alleles, one from each parent, for any given genomic location where such variation exists. If the two alleles are the same, the individual is homozygous for that allele, and if the alleles are different, the individual is heterozygous
. Alleles can have important effects within the body, as the way that two different alleles interact with each other can sometimes result in different observable traits in a person
