Applications of minisatellite variant repeat (MVR) mapping for maternal identification from remains of an infant and placenta.

Minisatellite variant repeat (MVR) mapping using the polymerase chain reaction (PCR) at D1S8 (MS32) was applied to a practical forensic case of an infant and placenta found in an incinerator. They were thought to be left for a few days postmortem, and the infant was severely burnt when found. DNA was extracted from the infantile muscle and maternal placental hematoma. MVR-PCR analysis as well as other common DNA typing (D1S80, HLA-DQA1) were performed on both DNA samples. Both MVR diploid codes were matched although some extra faint bands in the ladder were observed from the maternal placental sample, which probably indicated superimposing of an allele derived only from the mother, and not the infant. In order to detect the original maternal alleles, three flanking polymorphic sites were typed and allele-specific MVR-PCR was performed. Finally, one maternal allele not inherited by the infant and two alleles from the infant were typed. Two alleles suggested the infant and/or mother was Japanese. The two diploid codes including one possibly from the mother were deduced and compared with other codes in the databases for evaluating the discriminating power.