Allelic distribution of four tetranucleotide repeat loci (D3S1358, D18S51,D19S253, and FGA) in a population from Porto (North Portugal)

Allele frequencies for four short tandem repeat loci were determined in a p opulation sample from Porto (North Portugal), using the polymerase chain re action (PCR), in order to investigate possible genetic differences between populations from the center and north of Portugal. After denaturing PAGE el ectrophoresis, nine alleles were identified for D3S1358 (n = 256), 13 allel es for D18S51 (n = 235), 10 alleles for D19S253 (n = 238), and 15 alleles f or FGA (n = 181). No deviations from Hardy-Weinberg equilibrium were found. The allele frequencies observed are similar to those of the Portuguese pop ulation compared except for the D3S1358 system.