Kinship analysis on single cells after whole genome amplification

Area of Science:

• Forensic Genetics
• Molecular Biology
• Genomics

Background:

• Short Tandem Repeat (STR) and Single Nucleotide Polymorphism (SNP) genotyping are established forensic tools.
• Kinship analysis after whole genome amplification (WGA) of single cells remains understudied.
• WGA is crucial for applications like cell-based non-invasive prenatal testing (cbNIPT) and pre-implantation genetic diagnosis (PGD).

Purpose of the Study:

• To evaluate the efficacy and evidential value of STR and SNP genotyping for single-cell discrimination after WGA.
• To compare fixed and unfixed cells in kinship analysis.
• To assess the impact of parental genotype availability on evidential value.

Main Methods:

• Genotyping of 24 single cells (fixed and unfixed) from three families using STR and SNP methods after WGA.
• Analysis of offspring-parent duos and trios.
• Comparison of sequence-based SNP genotyping with length-based STR genotyping.

Main Results:

• Both STR and SNP genotyping achieved 100% sensitivity and specificity in all tested conditions.
• Fixed and unfixed cells showed similar evidential value.
• Sequence-based SNP genotyping yielded higher evidential value than STR genotyping post-WGA.
• The availability of both parents' genotypes significantly increased the evidential value.

Conclusions:

• STR and SNP genotyping are robust methods for single-cell kinship analysis following WGA.
• SNP genotyping provides superior evidential value compared to STR genotyping in WGA-based single-cell analysis.
• Including both parental genotypes enhances the reliability of forensic kinship assessments.