Short tandem repeat technology has diverse applications: Individual identification, phylogenetic reconstruction and chimerism based post haematopoietic stem cell transplantation graft monitoring

BACKGROUND: Short Tandem Repeat (STR) loci are widely considered to be effective for variety of applications including forensic applications, phylogenetic reconstruction and chimerism based post Haematopoietic Stem Cell Transplantation (HSCT) graft monitoring. For each application, specific sets of STR loci are used.
AIMS: In the present study, we have attempted to use same set of STR loci for varied purposes based on their efficacy and informativity. SETTINGS AND DESIGN: Population and patient based study.
MATERIALS AND METHODS: We have analyzed 5 STR loci - vWA, Tho1, FES, F13 and TPOX in 1000 North Indians. All five markers were also analyzed for chimerism based graft monitoring after HSCT in 42 HLA matched pair of patient-donor to predict the outcome of transplantation.
STATISTICAL ANALYSIS: The analysis was done for Hardy Weinberg equilibrium (HWE), Heterozygosity, Polymorphism information content (PIC) and Power of Exclusion and Phylogenetic assessment.
RESULTS AND CONCLUSIONS: High allelic variability in term of Heterozygosity (0.68-0.76), PIC (0.66-0.74) and high Power of exclusion (0.28-0.38) indicating high forensic utility. The ensuing PC plots finely resolved three basal clusters corresponding to three geo-ethnic groups of African, Orientals, and Caucasians. In post HSCT chimerism analysis, it was found that together these markers were informative in 38 pairs (98%) and were able to predict the chimerism status successfully. There is a possibility that these STR loci along with forensic and phylogenetic importance, can predict the outcome of HSCT successfully.

Keywords
Short Tandem Repeat, Chimerism, Phylogeny, Haematopoietic Stem Cell transplantation, Forensics