Question: hi agian i was just wondering because i have had a DNA test befor and i wanted the prosess they have to go through to find out who the child's rightful parents are ??? thanks :) xx

Ken Dutton-Regester answered on 12 Mar 2012:

Yeah sure, a little bit of more information- was hard to go into much detail in the chat. Usually they test regions called ‘short tandem repeats’. These are small regions of your DNA that are repeated at differnent amounts in different people. As an example- at one position of your DNA there might a repeat of TGG, and in one person that 3 letter code is repeated 5 times while in another person its repeated 10 times. When they do a parental test they check about 8-10 of these different repeat areas. With this amount of variability (between the number of repeat regions and the number those regions are repeated) they can accurately determine relatedness between people. As you have 2 copies of DNA (one from the mother, one from the father), when a child is tested they compare the profiles between the mum and dad as well and get pretty accurate results to the likilehood of being related. Not sure what the exact percentage accuracy the tests are but I imagine they are pretty high (like over 99%) and are pretty reliable.