Genetic structure of the human population in the Po delta.

The genetic structure of the population of Ferrara Province in the Po delta in Italy was investigated using chi 2 analysis, kinship analysis, analysis of correspondences, and geographical mapping of principal components of gene frequencies. chi 2 Analysis tests for Hardy-Weinberg equilibrium and for heterogeneity of gene and phenotype frequencies; kinship analysis tests for association between indicators of genetic and geographic proximity; analysis of correspondences relates localities and genetic systems in an eigenvectorial space; and geographic mapping displays the principal components of gene frequencies in the real space. In 1,364 adults in 26 residential units, seven presumably neutral isoenzyme systems were typed; ACP1 ESD, GLO I, GPT, PGD, PGM1 and PGP. It was found that average kinship for these neutral systems is correlated with geographic distance in this small area, but not as strongly as kinship for beta-thalassemia. A north-south gradient was observed for ESD. Analysis of correspondences indicated GPT, PGM1, and GLO I as the systems contributing most to differentiation within the province. The maps obtained from principal components of gene frequencies were consistent with the migrational history of the area.