Gilles de la Tourette syndrome in a cohort of deaf people

Choline acetyltransferase may contribute to the risk of Tourette syndrome: Combination of family-based analysis and case-control study

OBJECTIVES

Twin and family analyses have revealed a genetic contribution to Tourette syndrome (TS) and post-mortem studies have raised the intriguing possibility of a reduction in cholinergic interneuronsin TS patients.

METHODS

We selected five tag SNPs (rs100824791, rs12264845, rs1880676, rs3793790 and rs3793798) of choline acetyltransferase (CHAT) from the Han Chinese population Hapmap database. Genotyping was conducted on 401 TS nuclear family trios and 405 control subjects. Transmission disequilibrium test (TDT) and haplotype relative risk (HRR) analyses were used to analyse the family-based study and a case-control study was also used to assess the genetic susceptibility to TS.

RESULTS

The results revealed a significant over-transmission of rs3793790 (TDT, χ²=9.121, P = 0.003; HRR, χ²=6.579, P = 0.01), while case-control analysis found no differences between the two groups (genotype, χ²=0.436, P = 0.804; allele, χ²=0.149, P = 0.700). Also, rs3793798 also indicated a positive association associated with TS (TDT, χ²=5.025, P = 0.028; HRR, χ²=0.250, P = 0.617). However, the other three SNPs investigated were found not to be associated with TS in both in the family-based and case-control studies.

CONCLUSIONS

Our association analysis demonstrates that CHAT may contribute to TS susceptibility in the Han Chinese population. This gives strong support to the involvement of cholinergic interneurons in the aetiology of TS and reveals a potential therapeutic target.

Tic Disorders and PANDAS

Tics are the most common movement disorder in childhood and are a frequent reason for referral to child neurology clinics. The purpose of this review is to examine the phenomenology of tics, discuss what is known regarding their genetic and pathophysiological causes and to evaluate current treatment options. The evidence for the evaluation and treatment of the controversial diagnosis of pediatric autoimmune neuropsychiatric disorders associated with group A streptococci (PANDAS) will also be reviewed. With improved understanding of tic disorders, their etiology and response to current treatment options, we may be able to more effectively diagnose them and identify novel treatment strategies.