Journal of Forensic Research

Assessment of the Inbreeding Effect on Y-STR Profiles in the Lebanese Population

Abstract

Mouayyad Al-Azem, Nassib Dagher, Marc Obeid, Sarah Abbas, Hiba Othman and Issam Mansour

Y-STR profiling is gaining interest in forensic investigations. However, differentiation resulting from genetic stratification by genetic relatedness could be very pronounced in specific populations and thus imposing a possible limitation to Y-STR applications. In Lebanon, published data showed that endogamy average rate amounts up to 88%. Thereby, it is essential to determine the effect of inbreeding on Y-STR haplotype match probability and its consequences upon the analysis of forensic and paternity studies in the Lebanese population. A total of 241 male samples from seven villages were tested with two different haplotype sizes using the Y-filer Kit (Applied Biosystems) which includes: DYS19, DYS390, DYS391, DYS392, DYS393, DYS389I/II, DYS385a/b, DYS437, DYS438, DYS439, DYS456, DYS456, DYS448 and Y-GATA-H4 systems, and the Y-23 Kit (Promega Corporation) which includes six extra systems: DYS576, DYS570, DYS549, DYS643, DYS533 and DYS481. Results showed that some haplotypes were common among unrelated males carrying different family names. The most common haplotype appeared as frequently as 19 times in 36 males from one village. The use of the Y-23 profile increased the haplotype diversity and discrimination power and decreased the match rate. Nevertheless, a significant number of profile matches among unrelated individuals belonging to the same village were still observed.