HLA class II typing in newborns reveals a low frequency of the DRB104 allele and a high frequency of DRB111 allele in three regions of continental Italy

• Published in: Human immunology 2004-04, Vol.65 (4), p.366-372
• Main Authors: Galgani, Andrea, Petrone, Antonio, Spoletini, Marialuisa, Hodge, Aaliyah, Del Buono, Maria Luisa, Locatelli, Mattia, Buzzetti, Raffaella
• Format: Article
• Language: English
• Subjects: Caucasian; Diabetes Mellitus, Type 1 - diagnosis; Diabetes Mellitus, Type 1 - epidemiology; Diabetes Mellitus, Type 1 - genetics; Gene Frequency; Genetic Predisposition to Disease; Histocompatibility Testing; HLA-DQ Antigens - genetics; HLA-DQ beta-Chains; HLA-DQB1; HLA-DR Antigens - genetics; HLA-DRB1; HLA-DRB1 Chains; Humans; Infant, Newborn; Italian population; Italy - epidemiology; PCR-SSO
• ISSN: 0198-8859; 1879-1166
• DOI: 10.1016/j.humimm.2003.12.012

As part of a longitudinal study aimed at defining the natural history of prediabetic autoimmunity and predicting the risk of future cases of type 1 diabetes, 3607 newborns from three regions of continental Italy (Lombardia, Liguria, and Lazio) were subjected to genetic testing to determine human leukocyte antigen-DRB1 (HLA-DRB1) and -DQB1 allele and phenotype frequencies. Polymerase chain reaction and immobilized sequence-specific oligonucleotide probe assays were used to identify ten DRB1 allele lineages and three DQB1 alleles. No major inter-regional differences emerged in the allelic distribution indicating homogeneous distribution of the HLA DRB1-DQB1 alleles among the three regions analyzed. Comparison of our data with those published for other Caucasian populations reveals that these three regions are characterized by a very low frequency of DRB1*04 (8%) and a high frequency of DRB1*11 (25%). The phenotype frequencies of HLA-DQB1*0302 and DQB1*0602 observed are also lower than those reported for other populations. Furthermore, the DRB1*04-DQB1*0302 haplotype was relatively infrequent in our population (5.3% of the newborns tested). These findings furnish a genetic “portrait” of the populations of the analyzed regions that will be useful not only for investigation of the genetic risk of type 1 diabetes mellitus in Italy but also for studies of other autoimmune diseases related to HLA genotypes.