Objective: To evaluate the results of the 2012 interlaboratory comparison for forensic deoxyribonucleic acid (DNA) typing including autosomal short tandem repeat loci (aSTR), Y-chromosome short tandem repeat loci (Y-STR), X-chromosome short tandem repeat loci (X-STR) and mitochondrial DNA (mtDNA).

Material and Method: The analysis was performed using 4 blood samples stored on FTA® cards. Twelve laboratories in Thailand participated in this study. The results from each participant were compared with the consensus results.

Results: The analysis of aSTR, Y-STR, X-STR and mtDNA were performed in 12 (100.0%), 8 (66.7%), 6 (50.0%) and 7 (58.3%) laboratories, respectively. All DNA profiles of aSTR, Y-STR and X-STR from all the participating laboratories showed the same STR profiles. However, the calculation of forensic DNA typing statistical values and the format of laboratory reports among these laboratories showed several variations. Only the mtDNA test showed some variations among the laboratories.

Conclusion: For aSTR, Y-STR and X-STR tests, the trainings in statistical calculation of forensic DNA typing are required. For mtDNA test, workshop training should be established. Furthermore, a standard guideline for forensic DNA typing reports should be released in order to provide all the necessary information in the laboratory reports.