Detection of genetic structures at short distances in the Pisa area.

The genetic structure of the population of the urban and suburban area of the town of Pisa in Tuscany in Central Italy was studied in 1,174 adults residing in 4 zones in each of 3 sampling areas, using the phenotype and gene frequencies of 9 red cell enzymes. The area investigated has a surface of about 30 km2. The enzymes were: acid phosphatase (ACP1), adenosine deaminase (ADA), adenylate kinase (AK1), esterase D (ESD), glyoxalase I (GLOI), glutamic-pyruvic transaminase (GPT), 6-phosphogluconate dehydrogenase (6-PGD), phosphogluco-mutase 1 (PGM1), and phosphoglycollate phosphatase (PGP). For the analysis of the distributions of phenotype and gene frequencies, standardised variances, kinship profiles, analysis of correspondences and isonymy were used. It was found that in this area genetic differentiation (possibly due to recent immigration) can be perceived even at short geographic distances, indicated by the significant regression of kinship on distance, especially visible in the ADA and GPT systems.