Table 1.

Carriage rates of IL-1 receptor antagonist–VNTR polymorphism alleles in Caucasian and African-American juvenile idiopathic inflammatory myopathy (JIIM) patients and in race-matched normal controls^*

IL-1RN VNTR allele	Caucasian controls n (%)	Caucasian JIIM n (%)	P	Pcorr	Odds ratio (95% CI)	African- American controls n (%)	African- American JIIM n (%)	P	Pcorr	Odds ratio (95% CI)
A1	266	193	0·015	0·037	2·5	170	42	NS
	(90·2%)†	(96·0%)			(1·1–5·8)	(96·6%)†	(97·7%)
A2	137	88	NS			29	9	NS
	(46·4%)‡	(43·8%)				(16·5%)‡	(20·9%)
A3	8	5	NS			2	3	0·038	0·07	6·5
	(2·7%)	(2·5%)				(1·1%)	(7·0%)			(1·1–40·3)
A4	2	1	NS			5	0	NS
	(0·7%)	(0·5%)				(2·8%)	(0%)

^*Carriage rate is the proportion of individuals who have at least one copy of the investigated allele.A5 was not present in any controls or patients of either race. Total numbers of subjects studied: Caucasian controls = 295; Caucasian JIIM = 201; African-American controls = 176; African-American JIIM = 43.

^†A1, Caucasian versus African-American controls: P = 0·01, P _corr= 0·018.

^‡A2, Caucasian versus African-American controls: P = 0·001, P _corr= 0·001.