Frequencies of HLA class II alleles in Piedmont (northern Italy).

HLA class II gene frequencies were analysed in a panel of 101 unrelated individuals with Piedmontese ancestors living in Piedmont (north western Italy). A class II genomic typing was performed using the XI Histocompatibility Workshop protocol based on locus specific amplification by Polymerase chain Reaction (PCR) of class II gene second exon and hybridization with sequence specific oligonucleotides (SSO). Compared to other HLA typing techniques, this protocol defines more class II subtypes and analyses HLA-DP gene polymorphisms. The frequencies of alleles at DRB1, DRB3, DRB4, DRB5, DQA1, DQB1, DPA1, DPB1 loci are reported. Linkage disequilibrium analysis between DPA1-DPB1 and DRB1-DPB1 alleles is also reported.