Association study of the excitatory amino acid transporter 2 (EAAT2) and glycine transporter 1 (GlyT1) gene polymorphism with schizophrenia in a Polish population

Figures & data

Table 1 SLC1A2 (rs4354668) SNP genotypes and allele distribution in patient and control groups

Group	N	Genotype distribution					Allele frequency
		A/A	A/C	C/C	χ^2	p	A	C	χ^2	p
Patients	393	129 (32.8%)	188 (47.8%)	76 (19.3%)	1.69	0.43	446 (56.7%)	340 (43.3%)	0.64	0.42
Controls	462	154 (33.3%)	234 (50.6%)	74 (16.0%)			542 (58.7%)	382 (41.3%)
Total	855	283 (33.1%)	422 (49.4%)	150 (17.5%)			988 (57.8%)	722 (42.2%)
Female patients	157	60 (38.2%)	68 (43.3%)	29 (18.5%)	5.22	0.07	188 (59.9%)	126 (40.1%)	0.22	0.64
Female controls	238	73 (30.7%)	131 (55.0%)	34 (14.3%)			277 (58.2%)	199 (41.8%)
Total female	395	133 (33.7%)	199 (50.4%)	63 (15.9%)			465 (58.9%)	325 (41.1%)
Male patients	236	69 (29.2%)	120 (50.8%)	47 (20.0%)	2.51	0.28	258 (54.7%)	214 (45.3%)	1.89	0.17
Male controls	224	81 (36.2%)	103 (46.0%)	40 (17.8%)			265 (59.2%)	183 (40.8%)
Total male	460	150 (32.6%)	223 (48.5%)	87 (18.9%)			523 (56.8%)	397 (43.2%)

Table 2 SLC6A9 (rs2486001) SNP genotypes and allele distribution in patient and control group

Group	N	Genotype distribution					Allele frequency
		G/G	G/A	A/A	χ^2	p	G	A	χ^2	p
Patients	393	277 (70.5%)	103 (26.2%)	13 (3.3%)	0.18	0.91	657 (83.6%)	129 (16.4%)	0.08	0.78
Controls	462	328 (71.0%)	121 (26.2%)	13 (2.8%)			777 (84.1%)	147 (15.9%)
Total	855	605 (70.8%)	224 (26.2%)	26 (3.0%)			1434 (83.9%)	276 (16.1%)
Female patients	157	113 (72.0%)	40 (25.5%)	4 (2.5%)	0.48	0.78	266 (84.7%)	48 (15.3%)	0.07	0.79
Female controls	238	171 (71.8%)	58 (24.4%)	9 (3.8%)			400 (84.0%)	76 (16.0%)
Total female	395	284 (71.9%)	98 (24.8%)	13 (3.3%)			666 (84.3%)	124 (15.7%)
Male patients	236	164 (69.5%)	63 (26.7%)	9 (3.8%)	1.76	0.41	391 (82.8%)	81 (17.2%)	0.29	0.59
Male controls	224	157 (70.0%)	63 (28.1%)	4 (1.9%)			377 (84.2%)	71 (15.8%)
Total male	460	321 (69.8%)	126 (27.4%)	13 (2.8%)			768 (83.5%)	152 (16.5%)

Table 3 The results of two–way ANOVA (gender and genotype distribution) for PANSS dimensions

Dimension	p-value
	SCL1A2 (rs4354668)			SCL6A9 (rs2486001)
	Gender	Genotype	Gender × genotype interaction	Gender	Genotype	Gender × genotype interaction
POS	0.41	0.73	<0.01	0.23	0.37	0.20
NEG	0.39	0.23	0.66	0.36	0.82	0.16
DIS	0.42	0.79	0.17	0.92	0.86	0.57
EMO	0.22	0.37	0.36	0.26	0.40	0.11
EXC	0.19	0.96	0.06	0.80	0.09	0.59

Abbreviations: POS, positive; NEG, negative; DIS, disorganization; EXC, excitation; EMO, emotional distress.

Table 4 Analysis of the clinical data and PANSS dimensions with respect to suicide attempts

	Total	S +	S –	p
Male	236 (60.1%)	46 (19.5%)	190 (80.5%)	0.80
Female	157 (39.9%)	29 (18.5%)	128 (81.5%)
Family history of schizophrenia	95 (24.2%)	21 (22.1%)	74 (77.9%)	0.39
Age (years)	41±12	38±11	42±13	<0.05
Duration of illness (years)	16±10	14±9	16±10	<0.05
Age of onset (years)	26±7	24±6	26±7	0.11
PANSS (points)
POS	23.2±5.5	23.9±5.5	23.0±5.7	0.23
NEG	23.2±5.9	23.9±6.1	23.1±5.4	0.26
DIS	31.7±6.9	30.5±6.8	32.0±7.5	0.09
EMO	22.1±5.0	23.6±4.9	21.8±5.0	<0.01
EXC	20.4±5.6	21.1±5.5	20.2±6.0	0.23

Notes: S + patients with suicide attempt history. S – patients without suicide attempt history. Significant p values <0.005 are in bold. 

Abbreviations: PANSS, Positive and Negative Syndrome Scale; POS, positive; NEG, negative; DIS, disorganization; EXC, excitation; EMO, emotional distress.