Non-Mendelian inheritance is a type of biological inheritance wherein the patterns of phenotypes do not accord with those as expected in Mendelian laws on inheritance. It includes extranuclear inheritance, gene conversion, infectious heredity, genomic imprinting, mosaicism, and trinucleotide repeat disorders.
Gene conversion is a non-Mendelian inheritance wherein a nonreciprocal gene transfer in which an allele converts the other allele into the same form as its self, hence, resulting in inheritance pattern that does not follow Mendelian rule. For instance, a cross between genotypes AA and aa would result in offspring with genotypes Aa. However, gene conversion makes possible to produce offspring containing AA or aa genotypes, thus,a a clear manifestation of non-Mendelian pattern of inheritance. It happens when an allele converts another allele (within or between chromosomes) during meiosis that is similar in DNA sequences as its own.