Association of MICA with rheumatoid arthritis independent of known HLA-DRB1risk alleles in a family-based and a case control study

Table 2 Association of MICA polymorphism within the second and combined first and second French Caucasian family cohort

	2nd French family cohort	1st + 2nd French family cohort
(a) All individuals without controlling for LD with HLA-DRB1
Minor allele	A	A
Frequency in cases/controls^a	27%/32%	25%/33%
Minor allele transmitted/untransmitted	37/46	63/94
Transmission rate	45%	40%
TDT P value	0.328	0.015
(b) Subgroup without HLA-DRB1 risk alleles
Minor allele transmitted/untransmitted	12/16	18/34
Transmission rate	43%	35%
TDT P value	0.450	0.027
(c) All individuals, controlling for LD with HLA-DRB1 by conditional logistic regression
OR (95% CI)^b	0.68 (0.4–1.15)	0.56 (0.38–0.83)
P value	0.158	0.003
LRT^c P value	0.122	0.002

^aControls are non-transmitted alleles; ^bodds ratio of transmission of minor allele versus transmission of major allele as determined in logistic regression; ^clikelihood ratio test evaluating model including HLA-DRB1 alleles S2 and S3P and MICA-250 versus S2 and S3P only. For the HLA-DRB1 locus, allele L was used as reference. Effects of S2 and S3P alleles are presented in the online supplement (Additional data file 3). CI, confidence interval; LD, linkage disequilibrium; TDT, transmission disequilibrium test.