RESUMO
Genetic associations of TNFR2, VDR (Bsm I and Fok I), A2M, GSTT(1), GSTM(1) and ACE in South Asian and Caucasian patients with rheumatoid arthritis (RA) were assessed in this study. DNA samples from South Asians (134 cases, 149 controls) and Caucasians (137 cases, 150 controls) from the East Midlands of the United Kingdom were genotyped for seven polymorphisms. All cases were rheumatoid-factor positive. Significant genetic associations were observed with TNFR2 R-R (OR = 3.16, CI 1.20-9.26, P < 0.05), A2M 1-1 (OR = 2.09, CI 1.21-3.64, P < 0.05) and GST T(1)null (OR = 1.97, CI 1.07-3.68, P < 0.05) among Caucasian patients. In South Asians, VDR Bsm I B-B genotype (OR = 2.08, CI 1.23-3.52, P < 0.05), A2M 2-2 genotype (OR = 3.99, CI 1.19-17.18, P < 0.05), and GST T(1)null genotype (OR = 2.81, CI 1.40-5.77, P < 0.002) genotypes were associated with RA. In the majority of cases, recessive and multiplicative modes of inheritance explained the observed associations. This study demonstrates that ethnicity affects the genetic associations in RA.
Assuntos
Artrite Reumatoide/genética , Estudos de Associação Genética/métodos , Glutationa Transferase/genética , Peptidil Dipeptidase A/genética , Receptores de Calcitriol/genética , Receptores Tipo II do Fator de Necrose Tumoral/genética , alfa-Macroglobulinas/genética , Adulto , Idoso , Artrite Reumatoide/enzimologia , Artrite Reumatoide/etnologia , Ásia/epidemiologia , Ásia/etnologia , Povo Asiático/etnologia , Povo Asiático/genética , Humanos , Pessoa de Meia-Idade , Reino Unido/epidemiologia , Reino Unido/etnologia , População Branca/etnologia , População Branca/genéticaRESUMO
OBJECTIVE: To compare the distribution and assess genetic associations of the PTPN22 R620W single-nucleotide polymorphism among South Asian (Asiatic Indian) patients with rheumatoid arthritis (RA) and ethnically matched controls. METHODS: DNA samples from 133 rheumatoid factor-positive South Asian RA patients and 149 control subjects from the East Midlands of the UK were genotyped for PTPN22 R620W polymorphism. Genotyping was performed by the polymerase chain reaction-restriction fragment length polymorphism method. RESULTS: The PTPN22 *T allele frequency was lower than in the Caucasian populations, but the disease association was significant (odds ratio 5.87, 95% confidence interval 1.68-20.52). Similar association was observed for genotypes containing *T allele. CONCLUSION: Our results suggest that the T variant acts as a susceptibility allele for autoantibody-positive RA among South Asians.
