Genetic Orthology

Suprisingly Orthology is hitherto unknown in the English edition of wikipedia although there is a large body of literature available on PubMed(total 933 entries to date).

Orthologous genes are genes in different species that are so similar that evolutionary biologists assume a common ancestry. Orthologous genes can be found by both protein or nucleotide sequence alignment. Such an alignment can identify conserved region in which protein sequence did not change during evolution as these protein sequences are essential to proper function of the protein. Most pathogenetic mutations are located in those regions. Thus orthologous genes play an important role in medical interpretation of a mutation's pathogenetic relevance.