Objective: To investigate the polymorphism of 3 short tandem repeat (STR) loci D21S1442, D21S1413 and D21S1809 on human chromosome 21 in Shaanxi Han nationality in China.
Methods: Blood samples anti-coagulated with EDTA were collected from 160 unrelated Chinese Han individuals in Shaanxi Province. The genomic DNA was extracted with Chelex-100, amplified by PCR and analyzed using PAGE with silver staining.
Results: Nine, eight and seven alleles were detected at the loci of D21S1442, D21S1413 and D21S1809, respectively. The genotype distributions of all the 3 loci were in accordance with Hardy-Weinberg equilibrium. The heterozygosities of the 3 loci were 0.750, 0.742 and 0.694, respectively. No linkage disequilibrium was found between the loci.
Conclusion: The 3 loci on chromosome 21 have high heterozygosity and polymorphic information content in Shaanxi Han population, suggesting their value as potentially useful genetic markers.