Which of the following DNA markers has the LOWEST discriminating power and is therefore NOT suitable as the sole basis for individual identification in forensic casework?

• A Short Tandem Repeats (STR) profiled at 15+ loci
• B Single Nucleotide Polymorphisms (SNPs) at informative loci
• C Mitochondrial DNA D-loop sequencing alone ✓
• D Combination of autosomal and X-STR profiles

Explanation

MtDNA D-loop (control region) sequencing has significantly lower discriminating power than nuclear STR profiling because mtDNA is maternally inherited and shared among all maternal-line relatives. Multiple unrelated individuals in a population can share the same mtDNA haplotype. It is used for inclusion/exclusion but cannot individualise to the extent that autosomal STRs can. SNP panels and multi-locus STR profiles have far greater discriminating power.

Reference: The Essentials of Forensic Medicine and Toxicology (Narayan Reddy), 34th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.