Genetic Diversity of the D1S80 VNTR Locus within a Medical Laboratory Science Cohort

Abstract

This study established the precise allele and genotype distributions of the D1S80 variable number tandem repeat (VNTR) locus within a localized cohort of 30 Medical Laboratory Science students in Olongapo City, Philippines to evaluate regional genetic conservation and potential bottleneck effects. Genomic DNA isolated from buccal mucosa samples was amplified via Polymerase Chain Reaction using specific primers, and the resulting amplicons were separated using 2.0% agarose gel electrophoresis. Visualization revealed a highly restricted, dimorphic allelic profile consisting exclusively of 400-bp and 500-bp fragments. The observed genotype distribution consisted of 10 homozygous individuals for the 400-bp allele, 8 homozygous individuals for the 500-bp allele, and 12 heterozygous individuals. Direct gene counting established an exceptionally balanced allelic split, yielding a 400-bp allele frequency of 0.533 (53.3%) and a 500-bp allele frequency of 0.467 (46.7%). A Chi-Square goodness-of-fit test demonstrated that these observed genotype distributions did not statistically deviate from theoretical expectations (χ2 = 1.162, p = 0.281), confirming that this micro-population maintains a stable genetic structure in strict Hardy-Weinberg Equilibrium. The class's DNA traits are predictable and following normal laws of inheritance. This combination of low overall allelic variety and stable equilibrium points toward a localized founder effect or historical population bottleneck rather than active evolutionary selection or systemic laboratory errors like allelic dropout. Ultimately, these outcomes highlight the regional genetic conservation of lower-range repeat units within the localized demographic, and underscore the diagnostic necessity of utilizing modern, multiplexed short tandem repeat networks over isolated VNTR analysis in forensic and clinical molecular testing.