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.
Departamento de Pediatria, Escola Paulista de Medicina, Universidade Federal de São Paulo, Brasil.
M
M
Gerbase-Delima
L C
LC
Pinto
A
A
Grumach
M M
MM
Carneiro-Sampaio
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