Table 2 Alleles and genotypes frequencies for BDNF c.196G > A (rs6265) polymorphism in studied groups

Patients with bruxism (AB)

n = 104

47 (45.1%)

55 (52.9%)

2 (2.0%)

146 (71.6%)

58 (28.4%)

Males (n = 26)

16 (61.5%)

9 (34.6%)

1 (3.9%)

41 (78.9%)

11 (21.1%)

Females (n = 78)

31 (39.7%)

46 (59.0%)

1 (1.3%)

108 (69.2%)

48 (30.8%)

Control group (C)

(n = 193)

116 (60.2%)

67 (34.7%)

10 (5.1%)

299 (77.5%)

*1000Genomes: 80.0%

87 (22.5%)

*1000Genomes: 20.0%

Control males

(n = 97)

63 (65.0%)

29 (29.9%)

5 (5.1%)

155 (79.9%)

39 (20.1%)

Control females

(n = 96)

53 (55.2%)

38 (39.6%)

5 (5.2%)

144 (75.0%)

48 (25.0%)

Comparisons of allelic and genotypic frequencies between groups under the study

[GG + GA]vs[AA]

[GG]vs[GA + AA]

[GG]vs[AA]

[G]vs[A]

[A]vs[G]

AB** versus C

OR, 95% CI

P value

OR = 0.36

[0.08–1.67]

P = 0.174

OR = 0.55

[0.34–0.89]

P = 0.014

OR = 2.03

[0.43–9.60]

P = 0.365

OR = 0.735

[0.50–1.08]

P = 0.116

OR = 1.36

[0.93–2.00]

P = 0.116

AB males versus C males

OR, 95% CI

P value

OR = 0.74

[0.08–6.59]

P = 0.783

OR = 0.86

[0.35–2.11]

P = 0.747

OR = 1.27

[0.14–11.65]

P = 0.832

OR = 0.94

[0.44–1.99]

P = 0.867

OR = 1.07

[0.50–2.26]

P = 0.867

AB females** versus C females OR, 95% CI

P value

OR = 0.27

[0.03–2.07]

P = 0.158

OR = 0.54

[0.29–0.98]

P = 0.042

OR = 2.93

[0.33–26.19]

P = 0.317

OR = 0.75

[0.47–1.20]

P = 0.231

OR = 1.33

[0.83–2.14]

P = 0.231

AB females** versus AB males

OR, 95% CI

P value

OR = 0.33

[0.02–5.38]

P = 0.410

OR = 0.41

[0.17–1.03]

P = 0.053

OR = 1.93

[0.11–33.05]

P = 0.642

OR = 0.60

[0.29–1.28]

P = 0.183

OR = 1.66

[0.79–3.50]

P = 0.183

C females versus C males

OR, 95% CI

P value

OR = 1.01

[0.28–3.61]

P = 0.987

OR = 0.67

[0.37–1.19]

P = 0.167

OR = 0.84

[0.23–3.06]

P = 0.793

OR = 0.76

[0.47–1.22]

P = 0.250

OR = 1.33

[0.82–2.14]

P = 0.250