Association between polymorphisms of collagen genes and susceptibility to intervertebral disc degeneration: a meta-analysis

Table 1 Baseline characteristics of the studies included in the meta-analysis

References	Country	Conditions	Sample size		Genotyping method	Polymorphism	NOS
References	Country	Conditions	Case	Control	Genotyping method	Polymorphism	NOS
Annunen [18]	Finland	IVDD	314	202	CSGE, sequencing	Trp2	8
Paassilta [19]	Finland	LDD	171	321	CSGE, sequencing	Trp3	7
Noponen-Hietala [46]	Finland	LDD	29	56	CSGE, sequencing	Trp2, Trp3	7
Pluijm [15]	Netherland	IVDD	118	375	PCR–RFLP	Sp1	8
Kales [44]	Greece	IVDD	105	102	PCR-pyrosequencing	Trp2, Trp3	8
Matsui [17]	America	IVDD	97	10	Sequencing	Trp2, Trp3	7
Tilkeridis [43]	Greece	LDD	24	12	Sequencing	Sp1	7
Jim [41]	China	IVDD	514	290	CSGE, sequencing	Trp2, Trp3	8
Solovieva [42]	Finland	LDD	77	77	CSGE, sequencing	Trp2, Trp3	8
Seki [40]	Japan	LDD	470	658	Sequencing, TaqMan	Trp2	8
Mio [22]	Japan	LDD	881	841	TaqMan	C4603T	8
Song [38]	China	IVDD	125	125	SNPstream	Trp2	7
Hyun [37]	Korea	LDD	205	101	Sequencing	Trp2	7
Zhu [36]	America	IVDD	25	7	NR	Trp2, Trp3	7
Eskola [39]	Denmark	LDD	66	154	SNaPshot	Trp3	8
Kelempisioti [35]	Finland	IVDD	150	246	SNaPshot	Trp2, Trp3	8
Lim [45]	Singapore	LDD	34	20	Sequencing, TaqMan	Trp2, Trp3	7
Koyama [34]	Japan	IVDD	44	55	TaqMan	C4603T	8
Omair [33]	Norway	LDD	146	188	MassARRAY	Trp3, C4603T	8
Rathod [32]	India	IVDD	100	100	Real-time PCR	Trp2, Trp3	7
Lin [14]	China	IVDD	375	118	PCR–RFLP	Sp1	8
Anjankar [26]	India	IVDD	50	50	PCR	Sp1	8
Bagheri [25]	Iran	IVDD	108	57	Tetraplex PCR	Trp2, Trp3	7
Liu [21]	China	LDD	657	532	TaqMan	C4603T	8
Koyama [24]	Japan	IVDD	101	114	TaqMan	C4603T	8
Hanaei [23]	Iran	IVDD	96	94	TaqMan	Trp2	7

IVDD, intervertebral disc degeneration; LDD, lumbar disc degeneration; CSGE, conformation-sensitive gel electrophoresis; PCR, polymerase chain reaction; RFLP, restriction fragment length polymorphism; NOS, Newcastle–Ottawa Scale

ISSN: 1749-799X