The Universal Set of 99 InDel Markers for Human Identification.

Area of Science:

• Forensic Genetics
• Human Identification
• Molecular Biology

Background:

• Short tandem repeat (STR) loci are standard for human identification.
• Insertion-deletion (InDel) markers offer potential as an alternative due to their biallelic nature and distribution.
• Developing a routine, high-throughput genotyping method for InDels is crucial for forensic applications.

Purpose of the Study:

• To select insertion-deletion (InDel) markers suitable for human identification.
• To establish a routine genotyping method for these selected InDels.
• To evaluate the efficacy of InDel markers as an alternative to STR loci in forensic contexts.

Main Methods:

• Analysis of allele distribution for known InDels across five major superpopulations (European, East Asian, South Asian, African, American).
• Selection of 99 InDel markers with a minor allele frequency (MAF) ≥ 0.30.
• Development of a single-step multiplex PCR followed by biochip hybridization for genotyping, with an average amplicon length of 72 bp.

Main Results:

• A set of 99 InDel polymorphisms was established with an average MAF of 0.397 across populations and marker distances ≥ 3 million bp.
• Expected combined random match probabilities ranged from 1.44 × 10^-41 to 3.68 × 10^-41 across superpopulations.
• Validation in Russian and Ecuadorian populations yielded high combined power of exclusion (CPE) values (e.g., 0.999999989 for Russians) and low random match probabilities.

Conclusions:

• The selected 99 InDel markers are sufficient for robust human identification across diverse populations.
• The developed multiplex PCR and biochip hybridization method provides a routine and efficient genotyping solution.
• This InDel-based approach serves as a viable and powerful alternative to traditional STR analysis in forensic science.