DNA help adoptees find surnames

Adoptees are using DNA tests to find the surnames of their biological fathers, says a BBC report.

This is how it works. Genetic materials are passed on through the family tree, from father to son, just like surnames. Therefore, it is likely that men who have the same surname have genetic similarities. Based on this assumption, male adoptees can find DNAs that match theirs and check if the males whose DNAs are similar to theirs, have the same surname.

A consumer genetic testing company Family Tree DNA has said that nearly 30 male adoptees who compared their DNAs with DNAs in the Ysearch database, have found their biological surnames.

There are adoptees who have found more than one individual whose DNAs match theirs, but have the same surname. So even though they do not find the exact match at first shot, they have a starting point on where to look for their particular surname.

The Family Tree DNA test has 67 genetic markers and their online database, Ysearch, has genetic data of 125,000 men, with their surnames.

According to genetic experts, it is easier to locate surnames if its rare. Unlike very common names, rare surnames if they are available in the database, can give a close match. With very common surnames, however, there are many branches of descent. In such cases, it would be difficult to isolate the line of descent that an adoptee is looking for.

There are many other variables that come into play as well. Mark Jobling, professor of genetics at the University of Leicester, UK, has been quoted by the BBC as saying that general DNA patterns might differ from country to country. There could also be rare markers that are spread across two or more surnames, which may lead to false matches.

In the future, there could be a possiblity of finding genetic variants related to only one surname leading to a very accurate matching, he added.