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The etiology of Tourette syndrome (TS) is multifactorial. TS vulnerability may be associated with genetic and environmental factors. From the genetic point of view, TS is heterogeneous. Previous studies showed that some single-nucleotide polymorphisms (SNPs) of the glutathione-S-transferase P1 ( GSTP1) gene can affect cellular proliferation and apoptotic activity and TS is a neurodevelopmental disorder. We guessed that there was a relationship between TS and genetic variants of the GSTP1 gene. Therefore, in this study, we aimed to test the hypothesis that GSTP1 SNPs were associated with TS. We performed a case-control study. One hundred twenty-one TS children and 105 normal children were included in the study. Polymerase chain reaction was used to identify the GSTP1 gene polymorphism at position rs6591256 (A/G, promoter polymorphism) in TS patients and normal children. The polymorphism at position rs6591256 in the GSTP1 gene revealed significant differences in the allele ( p=0.0135) and genotype ( p=0.0159) distributions between the TS patients and the control group. The A allele was present at a higher frequency than the G allele in the TS patients compared with the control group (odds ratio [OR]=1.91, 95% confidence interval [CI]: 1.14-3.21). The AA genotype was associated with susceptibility to TS with an OR of 2.38 for the AA versus AG genotype (95% CI: 1.29-4.41). These findings suggest that variants in the GSTP1 gene may play a role in susceptibility to TS. [ABSTRACT FROM AUTHOR]

Tourette syndrome (TS) is an etiologically heterogeneous disorder, the pathogenesis of which is incompletely understood. Poly(ADP-ribose) polymerase 1 ( PARP1) is involved in regulation of developmental processes and cellular differentiation, in transcription regulation, in DNA repair, and in cell death. However, the relationship between TS and single nucleotide polymorphisms (SNPs) of PARP1 is unknown. Therefore, the aim of this experiment was to test the hypothesis that whether the PARP1 SNP, rs1805404 (c.243C>T, Asp81Asp), had an association with TS. A case–control experiment was designed to test this hypothesis. 123 TS children and 122 normal children were enrolled in this study. Polymerase chain reaction restriction fragment length polymorphism was used for the detection of the PARP1 SNP, rs1805404, in TS patients and normal children. The data showed that there is a significant difference in genotype distributions between these two groups. The CT genotype was a risk factor for TS with an odds ratio of 2.34 for the CT versus TT genotype (95 % CI 1.16–4.74). The data also showed this SNP had an association with TS under recessive model ( P = 0.0426), and TT genotype had a protective effect against TS with an odds ratio of 0.50 (95 % CI 0.26–0.98). The findings of this study suggested that variants in the PARP1 gene might play a role in susceptibility to TS. [ABSTRACT FROM AUTHOR]

Tourette syndrome has a multifactorial etiology in which genetic, environmental, and immunologic factors interact to establish vulnerability. Various interleukin 1 genes are associated with several immunoinflammatory diseases. It is not known whether polymorphisms in those genes are involved in the pathogenesis of Tourette syndrome. In this association study, single nucleotide polymorphisms were used to investigate the distribution of genotypes of the interleukin 1 receptor antagonist gene (IL1RN; alias IL1RA) and of the interleukin 1β gene (IL1B) in patients with Tourette syndrome. A total of 159 children with Tourette syndrome and 175 healthy control subjects were included in the study. There was no significant difference between patients and control subjects in the distribution of genotype and allele frequencies for IL1B exon 5 and promoter region; however, the number of individuals homozygotic for IL1RN ∗1 was significantly greater (P < 0.0001), and the IL1RN ∗1 allele frequency was significantly higher (P < 0.0001), among patients than among control subjects. The odds ratio for developing Tourette syndrome in individuals with the IL1RN ∗1 allele, compared with IL1RN ∗2, was 7.65. Thus, the IL1RN gene may be a useful marker for prediction of the susceptibility to Tourette syndrome. [Copyright &y& Elsevier]

Missense mutations in the γ2 subunit of γ-aminobutyric acid (GABA) receptor gene have recently been described in families with idiopathic generalized epilepsies. This study aimed to evaluate whether polymorphisms of the γ2 subunit of the GABA receptor gene are associated with idiopathic generalized epilepsies. A total of 77 children with idiopathic generalized epilepsies and 83 normal control subjects were included in the study. Polymerase chain reaction was used to identify the C/T and A/G polymorphisms of the γ2 subunit of the GABA receptor gene on chromosome 5q33. Genotypes and allelic frequencies in both groups were compared. The γ2 subunit of the GABA receptor (nucleotide position 3145 in intron G-> A) gene in both groups was not significantly different. In contrast, the γ2 subunit of GABA receptor (SNP211037)-C allele frequency in patients with idiopathic generalized epilepsies was significantly higher than that in healthy control subjects (P = 0.002). The odds ratio for developing idiopathic generalized epilepsies in individuals with the γ2 subunit of the GABA receptor (SNP211037)-C/C genotype was 3.61 compared with individuals with the γ2 subunit of the GABA receptor (SNP211037)-T/T genotype. These data suggest that the γ2 subunit of the GABA receptor gene might be one of the susceptibility factors for idiopathic generalized epilepsies. [Copyright &y& Elsevier]

The pathophysiology of Tourette syndrome may involve the dopamine system. Dysfunction of the dopamine receptor D2 gene leads to many neuropsychiatric disorders. The objective of this study is to test the hypothesis that the dopamine receptor D2 gene may play a role in Tourette syndrome. A total of 151 children with Tourette syndrome and 183 normal control subjects were included in the study. Polymerase chain reaction was used to identify the Taq I DRD2 and DRD2 (H313H) polymorphisms of the dopamine receptor D2 gene. The genotype proportions of Taq I DRD2 and DRD2 (H313H) polymorphisms in the two groups were significantly different (P < 0.01 for both). The odds ratio for developing Tourette syndrome in individuals with the Taq I DRD2 A1 homozygote was 2.253 (95% confidence interval, 1.124-4.517) compared with individuals with the Taq I DRD2 A2 homozygote. The odds ratio for developing Tourette syndrome in individuals with the DRD2 (H313H) C homozygote was 2.96 (95% confidence interval, 1.398-6.269) compared with individuals with DRD2 (H313H) T homozygote. This study has demonstrated an association between the dopamine receptor D2 gene and Tourette syndrome. These data suggest that the dopamine receptor D2 gene or a closely linked gene might be one of the susceptibility factors for Tourette syndrome. [Copyright &y& Elsevier]

Interleukin-4 (IL-4) is a cytokine with anti-inflammatory properties. This study was undertaken to investigate whether IL-4 intron 3 gene polymorphism could be used as markers of susceptibility to febrile seizures and epilepsy of children. Children were divided into three groups: group 1, febrile seizures (n = 51); group 2, epilepsy (n = 43); and group 3, normal control group (n = 83). Polymorphisms for IL-4 intron 3 were detected by polymerase chain reaction. Genotypes and allelic frequencies for IL-4 intron 3 gene polymorphism in three groups were compared. We found that proportions of different IL-4 intron 3 polymorphisms in three groups were nonsignificantly different. Proportions of RP1 homozygote/heterozygote/RP2 homozygote for IL-4 intron 3 in three groups were as follows: group 1, 56.9/41.2/1.9%; group 2, 62.8/32.6/4.6%; and group 3, 62.7/33.7/3.6%. The proportion of RP1/RP2 for IL-4 intron 3 in three groups were as follows: group 1, 77.5/22.5%, group 2, 79.1/20.9%, and group 3, 79.5/20.5%. We concluded that the association of IL-4 polymorphisms with febrile seizures and epilepsy of children does not exist. IL-4 intron 3 polymorphism is not a useful marker for prediction of the susceptibility of febrile seizure and epilepsy of children. [Copyright &y& Elsevier]

Various studies have shown that brain-derived neurotrophic factor (BDNF) increased neuronal excitability. We tested that BDNF might be involved in the etiology of febrile seizures (FSs). A total of 186 Taiwanese children were divided into two groups: (1) FSs (n = 104); (2) normal control subjects (n = 83). A single base pair polymorphism SNP6265 (Val66Met) at position 196 was analyzed. Our findings suggest that the BDNF polymorphisms were not candidate genetic markers. [Copyright &y& Elsevier]