Table 2.

Genotype distribution of the studies included in this meta-analysis

Study ID	Year	Ethnicity	Disease	Case group			Control group			P for HWE
GDF5 rs143383				CC	CT	TT	CC	CT	TT
Mu J	2014	Asian	LDH	8	79	144	39	158	173	0.743
Mu J	2013	Asian	LBP	10	89	206	58	254	275	0.953
Williams FMK a	2011	Caucasian	LDD	21	103	70	218	586	464	0.159
Williams FMK b	2011	Caucasian	LDD	4	14	15	94	252	193	0.453
Williams FMK c	2011	Caucasian	LDD	6	23	25	119	312	273	0.067
Williams FMK d	2011	Caucasian	LDD	2	7	9	72	256	246	0.671
Williams FMK e	2011	Caucasian	LDD	1	8	5	16	42	58	0.073
Tülüce Y	2017	Caucasian	OA	24	39	32	8	39	30	0.366
Abd Elazeem MI	2017	Caucasian	OA	14	16	20	13	25	12	0.998
Sabah-Ozcan S	2016	Caucasian	OA	14	43	37	52	153	74	0.083
Xiao JL	2015	Asian	OA	5	47	62	19	54	53	0.396
Mishra	2013	Asian	OA	46	130	124	56	160	84	0.188
Tawonsawatruk T	2011	Asian	OA	11	41	38	23	47	33	0.424
Cao Z	2010	Asian	OA	11	115	150	26	113	159	0.397
Valdes AM	2009	Caucasian	OA	35	98	126	84	244	181	0.908
Tsezou A	2007	Caucasian	OA	30	126	95	44	125	99	0.669
Miyamoto Y a	2007	Asian	OA	31	243	444	58	330	473	0.966
Miyamoto Y b	2007	Asian	OA	19	97	197	48	193	244	0.283
Miyamoto Y c	2007	Asian	OA	31	266	701	70	371	542	0.552
Southam L a	2007	Caucasian	OA	52	238	219	126	372	324	0.262
Southam L b	2007	Caucasian	OA	36	136	102	194	563	439	0.549
Shin MH	2012	Asian	OA	38	305	382	106	689	942	0.176

^a,b,c,d and ^e denote an independent study in one article, respectively, HWE Hardy-Weinberg equilibrium, LDD lumbar disc degeneration, LDH lumbar disc herniation, LBP low-back pain, OA osteoarthritis