T300A polymorphism of ATG16L1 and susceptibility to inflammatory bowel diseases: A meta-analysis

Table 1 Reasons for study exclusion

Studies	Reasons
Glas et al[31], Török et al[32]	Data overlapped those of another article[17]
Cooney et al[33]	Data overlapped those of another article[8]
Weersma et al[34], Weersma et al[35]	Data overlapped those of another article[26]
Franke et al[36], Franke et al[37]	Data overlapped those of another article[5]
Fisher et al[38], Wtccc et al[40], Parkes et al[43], Yamazaki et al[45]	Other SNPs rather than rs2241880 SNP of ATG16L1 were analyzed
Beckly et al[39], Barrett et al[41], Libioulle et al[42], Raelson et al[44], Kugathasan et al[46]	Data could not be extracted

Table 2 Studies included in the meta-analysis

No.	First author	Year	Population	Number of participants used in analysis
				CD	UC	Controls
1	Hampe et al[5]1	2007	Germany, UK	2122	1227	2056, 1032 for CD, UC respectively
2	Baldassano et al[6]	2007	USA	142	NA	281
3	Büning et al[7]	2007	Germany, Hungary, Netherlands	614	296	707
4	Cummings et al[8]	2007	UK	645	676	1190
5	Prescott et al[9]	2007	UK	727	877	579
6	Rioux et al[10]2	2007	North-America	1571	353	1184, 207 for CD, UC respectively
7	Roberts et al[11]	2007	New Zealand	496	466	549
8	Yamazaki et al[12]	2007	Japan	481	NA	437
9	Amre et al[13]	2009	Canada	286	NA	290
10	Baptista et al[14]	2008	Brazil	180	NA	189
11	Fowler et al[15]3	2008	Australia	154	NA	420
12	Gaj et al[16]	2008	Poland	59	NA	140
13	Glas et al[17]	2008	Germany	768	507	1615
14	Lakatos et al[18]	2008	Hungary	266	149	149
15	Lappalainen et al[19]	2008	Finland	240	459	190
16	Latiano et al[20]	2008	Italy	667	668	749
17	Okazaki et al[21]	2008	Canada	208	113	314
18	Perricone et al[22]	2008	Italy	163	NA	160
19	Peterson et al[23]	2008	USA	555	NA	486
20	Van Limbergen et al[24]4	2008	Scotland	629	580	345
21	Zhi et al[25]	2008	China	40	40	50
22	Weersma et al[26]	2009	Holland	1684	1120	1350
23	Hancock et al[27]	2008	UK	586	NA	1156
24	Yang et al[28]	2009	Korea	377	NA	372
25	Newman et al[29]	2009	Canada	435	NE	895
Total				14 095	7531	15 849, 13 852 for CD, UC respectively

¹Data were extracted from the combination of panel A, panel B, panel C, and UC cohort; ²Only GWA study and replication cohort 2 study were included; ³Data from the cohort 1 study were not included in the analysis based on the use of data for controls from 251 families with IBD; ⁴Data of the UC group were obtained by communication with the authors of this publication. CD: Crohn’s disease; UC: Ulcerative colitis; NA: Not applicable (no such group); NE: Non-extractable or unavailable data.

Table 3 Summary of the association of the rs2241880 polymorphism and IBD determined in the meta-analysis

Comparisons	No. of studies	Effects model selection	OR (95% CI)	P-value
CD vs control	25	R	1.32 (1.26-1.39)	< 0.00001
UC vs control	14	F	1.06 (1.01-1.10)	0.02
Child-onset CD vs control	7	R	1.35 (1.16-1.57)	0.0001
Child-onset UC vs control	2	F	0.98 (0.81-1.19)	0.84

R: Random effects model; F: Fixed effects model.