title: HLA class II typing in newborns reveals a low frequency of the DRB1*04 allele and a high frequency of DRB1*11 allele in three regions of continental Italy.
abstract: 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.
authors.affiliation: Endocrinologia , University "La Sapienza", Rome, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Galgani
authors.forename: Antonio
authors.initials: A
authors.lastname: Petrone
authors.forename: Marialuisa
authors.initials: M
authors.lastname: Spoletini
authors.forename: Aaliyah
authors.initials: A
authors.lastname: Hodge
authors.forename: Maria Luisa
authors.initials: ML
authors.lastname: Del Buono
authors.forename: Mattia
authors.initials: M
authors.lastname: Locatelli
authors.forename: Raffaella
authors.initials: R
authors.lastname: Buzzetti
mesh_terms: D003922:Diabetes Mellitus, Type 1 / Q000175:diagnosis / Q000453:epidemiology / Q000235:genetics*; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D006683:HLA-DQ Antigens / Q000235:genetics; D059866:HLA-DQ beta-Chains; D006684:HLA-DR Antigens / Q000235:genetics*; D059811:HLA-DRB1 Chains; D006650:Histocompatibility Testing; D006801:Humans; D007231:Infant, Newborn; D007558:Italy / Q000453:epidemiology
chemical_list: D006683:HLA-DQ Antigens; D059866:HLA-DQ beta-Chains; C069051:HLA-DQB1 antigen; D006684:HLA-DR Antigens; D059811:HLA-DRB1 Chains