title: [Respective weight of genotypes DQA1 and DQB1 associated with insulin-dependent diabetes in French children].
abstract: Genetic susceptibility alleles have been identified at the DQ HLA region. The aim of the present study was to confirm the value of these markers, and to evaluate the respective weight in the risk of the different alleles at the DQA1 and DQB1 levels, identified by restriction mapping after polymerase chain reaction on exon 2. A significant enrichment in DQB1 alleles encoding for an aminoacid different from Aspartic acid at position 57 (NA) was observed in diabetic (n = 213) in comparison to control (n = 93) children (94% vs 52%; p < 10(-8)). Not all the given NA/NA allelic combinations were equally and positively associated to the disease. Homozygous "Ala/Ala" combinations carried the highest relative risk (OR = 12.3; p < 10(-8)), and among them, the *0201/*0302 genotype was more positively associated to type 1 diabetes (OR = 66; p < 10(-8)). A significant enrichment in DQA1 alleles encoding for Arginine at position 52 in diabetic children was also observed (82% vs 40%; p < 10(-8)). The *0301/*0501 (Arg/Arg) genotype was significantly associated to Type 1 diabetes (OR = 16.2; p < 10(-4)). The highest risk was carried by the whole genotype, a result which could be expected from the known linkage desequilibrium between HLA-DQA1 and DQB1, DRB1 loci. The frequency of Ala DQB1 alleles was low in the background non-at-risk population, although the incidence of the disease is low in our country.
authors.affiliation: INSERM U 120, Hôpital Robert-Debŕé, Paris, France.
authors.forename: I
authors.initials: I
authors.lastname: Fajardy
authors.forename: C
authors.initials: C
authors.lastname: Levy-Marchal
authors.forename: X F
authors.initials: XF
authors.lastname: Gu
authors.forename: R
authors.initials: R
authors.lastname: Krishnamoorthy
authors.forename: J
authors.initials: J
authors.lastname: Elion
authors.forename: P
authors.initials: P
authors.lastname: Czernichow
mesh_terms: D000293:Adolescent; D000328:Adult; D000483:Alleles; D002648:Child; D002675:Child, Preschool; D003922:Diabetes Mellitus, Type 1 / Q000235:genetics*; D005602:France / Q000453:epidemiology; D005787:Gene Frequency / Q000235:genetics; D005819:Genetic Markers / Q000235:genetics; D005838:Genotype; D006683:HLA-DQ Antigens / Q000235:genetics*; D006801:Humans; D012307:Risk Factors; D009626:Terminology as Topic; D044465:White People / Q000235:genetics*
chemical_list: D005819:Genetic Markers; D006683:HLA-DQ Antigens
vernacular_title: Part respective des génotypes DQA1 et DQB1 associés au diabète insulino-dependant chez des enfants français.