Hypervariability of the human thyroid peroxidase gene in Italy

Using a PCR based method, we determined hypervariable markers of the Thyroid Peroxidase gene (TPO-VNTR markers) by size classification of alleles in a total of 146 blood samples (76 from Sicily and 70 from Lombardy, South and North Italy respectively). A total of 22 alleles were identified. They varied in size from 6 (0.4 Kbp) to 27 (1.5 Kbp) repeats and showed a unimodal distribution (peak at 15 repeat number). Data were compared with those previously obtained in two other Italian samples from Calabria (South Italy) and from Sardinia. Heterogeneity G tests on allele frequency distributions led to the following conclusions: 1) as observerd for the majority of the known polymorphisms, the Sardinian sample is clearly distinguishable from all the others; 2) although on the whole no significant heterogeneity emerges from the comparison between southern and northern Italians, certain allelic frequencies are able to distinguish between groups.