DNA typing in cases of blood chimerism

A chimera is an organism whose cells derive from two or more distinct zygot e lineages. and therefore two different blood cell populations circulate in one individual. To point out the potential pitfalls in forensic analysis, a set of triplets (a girl and two boys) who revealed blood chimerism was in vestigated with four STR systems using PCR. The results indicated that a DN A profile based on DNA extracted from blood can lead to a false determinati on because the band pattern of each triplet contained a mixture of the orig inal genotype and the genotype of the siblings. Additional investigations o n biological materials other than blood must be made in order to find out t he real genetic characteristics of each child.