PNPLA3 polymorphism increases risk for and severity of chronic hepatitis C liver disease

Table 1 Baseline characteristics of patients from studies included in the analysis

Ref.	Study design	Controls (n)	Cases
			n	Ethnicity	M%	Mean age	Mean BMI	rs 738409 genotype count (CC:CG:GG)4
								FL	Hepatitis	Cirrhosis	HCC
Cai et al[39] (2011)	R	-	626	C	61.8	44.7	23.7	62:281	-	-	-
Valenti et al[40] (2011)	R	179	819	C + NA	56.4	57.4	24.8	269:219:73	-	119:172:229	17:21:12
Trépo et al[41] (2011)	R	-	537	C	63	49.4	25.5	136:106:31	-	108:85:23	-
Corradini et al[42] (2011)	P6	-	221	C	63	58	-	-	-	-	-
Nischalke et al[13] (2011)	P	190	162	C	57	56	28.4	-	-	45:31:05	40:33:08
Valenti et al[43] (2012)	P	-	567	NS	-	-	-	-	-	-	-
Valenti et al[15] (2012)	P6	-	602	NS	51	51	25.1	364:422	-	158:212	-
Guyot et al[12] (2013)	P	-	253	NS	54.2	56.7	27.3	-	-	140:75:38	54:26:13
Ezzikouri et al[44] (2013)	P	132	230	NA	45.2	63.63	-	-	47:71:11	-	43:35:23
Stättermayer et al[45] (2014)	R	-	478	NS	65.7	44.9	25.6	190:232	-	101:572	-
Ampuero et al[46] (2014)	P6	-	474	M	64.8	43.4	25.7	94:1263	-	-	-
Sato et al[47] (2014)	R	-	358	A	55.9	69.76	-	41:202	-	112:372	100:176:82
Yasui et al[48] (2014)	P6	-	276	A	40.6	58.2	23	23:75:39	45:66:38	20:31:21	-
Petta et al[14] (2015)	P	-	434	C	53.9	51.7	-	-	40:35:12	71:36:13	-
Nakaoka et al[49] (2015 )	P	-	231	A	44.6	62.9	22.5	-	-	90:272	12:22:14
Tamaki et al[50] (2015)	R	-	176	A	39.8	56.5	22.9	-	-	52:87:37	-
Huang et al[51] (2015)	R	-	1018	A	56.6	51.8	24.9	175:205:75	-	-	-
Petta et al[52] (2016)	P6	-	694	C	53	54	26.5	151:151:455	-	-	-
Ali et al[53] (2016)	P	-	937	M	70.1	49.5	-	-	-	172:2123	-
Summary		501	9093		57.6	52.7	25.1

¹C allele: G allele;

²CC + CG: GG;

³CC: CG + GG;

⁴Genotype counts were reported as ratios (CC wild genotype: CG heterozygote genotype: GG homozygote genotype) unless indicated by star(s);

⁵Calculated from percentages in the original article;

⁶Population based studies. A: Asian; BMI: Body mass index; C: Caucasian; FL: Fatty liver; HCC: Hepatocellular carcinoma; M: Mixed (Caucasians and non-Caucasians[46] and White/Black/Hispanic[53]); P: Prospective; R: Retrospective; M%: Males percentage; N: Number of cases; NA: North African; NS: Not specified in the original manuscripts (although all 4 studies included European referral centers only).

Table 2 Newcastle - Ottawa Scale on quality score of the included studies

Ref.	Selection				Comparability	Exposure			Total
	Independent validation	Case representation	Controls selection	Controls definition	Case and control design/analysis	Ascertainment of exposure	Same method of ascertainment	Same response rate
Cai et al[39] (2011)	1	1			2	1	1	1	7
Valenti et al[40] (2011)	1	1	1	1	2	1	1	1	9
Trépo et al[41] (2011)	1	1			2	1			5
Corradini et al[42] (2011)	1	1			2	1			5
Nischalke et al[13] (2011)	1	1	1	1	2	1	1	1	9
Valenti et al[43] (2012)	1	1			2	1	1		6
Valenti et al[15] (2012)	1	1			2	1	1		6
Guyot et al[12] (2013)	1	1			2	1			5
Ezzikouri et al[44] (2013)	1	1	1	1	2	1	1	1	9
Stättermayer et al[45] (2014)	1	1			2	1			5
Ampuero et al[46] (2014)	1	1			2	1	1	1	7
Sato et al[47] (2014)	1	1			2	1			5
Yasui et al[48] (2014)	1	1			2	1			5
Petta et al[14] (2015)	1	1			2	1			5
Nakaoka et al[49] (2015 )	1	1			2	1			5
Tamaki et al[50] (2015)	1	1			2	1	1	1	7
Huang et al[51] (2015)	1	1			2	1	1	1	7
Petta et al[52] (2016)	1	1			2	1	1	1	7
Ali et al[53] (2016)	1	1			2	1	1	1	7