An example of a polygenic trait is human skin color variation. Several genes factor into determining a person's natural skin color, so modifying only one of those genes can change skin color slightly or in some cases, such as for SLC24A5, moderately.
Case 1 â The Alleged Father has Recently Passed Away. If less than a week has passed since the deceased died, then if permission can be obtained, fingernail cuttings and a hair sample with root attached can be used to extract DNA samples to establish paternity. It is a more complex procedure than a buccal swab, but the DNA matching is just as accurate.
Case 2 â The Nature of the Sample. A major problem can exist if the alleged father is not only deceased, but has also been interred. In such a case, you wonât be able to use a sample direct from the body, and will have to seek some other indirect sample. It might sound the stuff of novels, but DNA samples can be taken from cigarette butts, drinking glasses and hairbrushes, and is just as relevant for DNA comparison testing as oral swabs are.