Table 1.

Summary of MDR1 association studies

Author	No of cases	Tested SNP	Population	Results
Schwab et al.	149 UC	C3435T	German	T allele associated with UC (p = 0.049)
	126 CD
Croucher et al.	307 UC	C3435T	German & British	No association
	562 CD
Brant et al.	119 UC	C3435T G2677T	USA	G2677 associated with IBD (p = 0.003)
	409 CD
Glas et al.	123 UC	C3435T	German	No association
	135 CD
Potocnik et al.	144 UC	Multiple intron, exon and promoter polymorphisms	Slovenian	2677T associated with UC (p = 0.02); Risk and protective haplotypes identified for UC and CD
	139 CD
Gazzouli et al.	85 UC	C3435T	Greece*	No association
	120 CD
Ho et al.	335 UC	C3435T	Scottish	3435T associated with UC (p = 0.02); 3435T associated with extensive colitis (p = 0.003)
	268 CD	G2677T
Onnie et al.	580 UC	C3435T	British	2677T associated with UC (p = 0.03)
	828 CD	G2677T
Urcelay et al.	330 UC	C3435T	Spanish*	C3435T CC genotype associated with CD (p = 0.007)
	321 CD	G2677T
Oostenbrug et al.	224 UC	C3435T	Dutch	No association
	533 CD
Lal et al.	112 UC	C3435T	Canadian	3435T allele associated with CD (p = 0.02)
	247 CD
Fiedler et al.	144 UC	C3435T	German	No association
	244 CD	G2677T
Fischer et al.	149 UC	C3435T	Hungarian	No association
	265 CD	G2677T
Ardizzone et al.	97 UC	C3435T	Italian	No association
	211 CD	G2677T
Huebner et al.	401 UC	G2677T	New Zealand	G2677T protective for UC (p = 0.02)
	483 CD

* Data not in Hardy-Weinberg equilibrium.