HLA antigens and haplotypes in IgA-deficient Brazilian paediatric patients.
In the present study we determined the HLA-A, B and DR antigenic and haplotypic frequencies in unrelated Brazilian Caucasian paediatric patients with IgA deficiency (IgA-D). Out of 17 IgA-D subjects typed for HLA A and B specificities, 12 (71%) presented B8 and/or B14; of 15 patients also typed for HLA-DR specificities, 14 (93%) were positive for at least one of the HLA markers previously reported to be associated with IgA-D, i.e. B8, B14, DR1, DR3 or DR7. The haplotypes B8, DR3, B14, DR1 and B13, DR7 were present in 43, 21 and 14% of the cases, respectively, while they have a frequency in the general population of 2, 2 and 1%, respectively. The concomitant association with the three IgA-associated haplotypes found in our study probably reflects the admixture of European genetic influences present in the Brazilian Caucasian population of São Paulo.
Gerbase-Delima
M
M
Departamento de Pediatria, Escola Paulista de Medicina, Universidade Federal de São Paulo, Brasil.
Pinto
L C
LC
Grumach
A
A
Carneiro-Sampaio
M M
MM
D001938:Brazil; D002648:Child; D002675:Child, Preschool; D005260:Female; D005838:Genotype; D015234:HLA-A Antigens / Q000235:genetics*; D015235:HLA-B Antigens / Q000235:genetics*; D006684:HLA-DR Antigens / Q000235:genetics*; D006239:Haplotypes; D006801:Humans; D017098:IgA Deficiency / Q000235:genetics* / Q000276:immunology*; D007223:Infant; D008297:Male; D010641:Phenotype
D015234:HLA-A Antigens; D015235:HLA-B Antigens; D006684:HLA-DR Antigens