title: [Role of aspartic acid at position 57 of the HLA-DQ beta chain in sporadic and familial forms of selective IgA deficiency].
abstract: BACKGROUND
  Selective IgA deficiency (IgAD) is the most frequent primary immunodeficiency in Caucasians. A protective effect of an aspartic acid residue at position 57 of the DQ beta chain against IgAD has been repeatedly described. The aim of our study was to determine, whether the genetic effect of non-aspartic acids (non-Asp) at position 57 of the DQ beta chain is different in familial and non-familial forms of IgAD.
  
  
  RESULTS
  Codon 57 genotyping was performed in 59 patients with sporadic from in 28 patients with familial forms of IgAD, and in 162 control persons. Significantly increased occurrence of the non-Asp residues at position 57 in IgAD patients compared to control persons was found, but there was no difference between familial and sporadic forms of IgAD. The association was not proved in six IgAD patients who were relatives of CVID patients.
  
  
  CONCLUSIONS
  The protective effect of non-aspartic acid at position 57 of the DQ beta chain is present in both sporadic and familial form of IgAD. This effect was not observed in IgAD relatives of CVID persons showing that a genetic background of this form might be different than in other forms of IgAD.
authors.affiliation: Oddĕlení genetiky-Výzkumný ústav zdraví dítĕte 662 62 Brno, Cernopolní 9. tfreiber@med.muni.cz
authors.forename: T
authors.initials: T
authors.lastname: Freiberger
authors.forename: J
authors.initials: J
authors.lastname: Litzman
authors.forename: E
authors.initials: E
authors.lastname: Vondrusková
mesh_terms: D000595:Amino Acid Sequence; D001224:Aspartic Acid / Q000235:genetics*; D003062:Codon; D017074:Common Variable Immunodeficiency / Q000235:genetics; D005838:Genotype; D006683:HLA-DQ Antigens / Q000235:genetics*; D006720:Homozygote; D006801:Humans; D017098:IgA Deficiency / Q000235:genetics*
chemical_list: D003062:Codon; D006683:HLA-DQ Antigens; D001224:Aspartic Acid