Histamine dysregulation was implicated as a rare cause of Tourette syndrome and other tic disorders a decade ago by a landmark genetic study in a high density family pedigree, which implicated a hypomorphic mutation in the histidine decarboxylase (Hdc) gene as a rare but high penetrance genetic cause.
In the current study we investigated if mice lacking the histamine producing enzyme HDC share the morphological and cytological phenotype with GTS patients by using magnetic resonance (MRI) and diffusion tensor imaging (DTI), unbiased stereology and immunohistochemistry.
A rare mutation in the enzyme that produces histamine (HA), histidine decarboxylase (HDC), has been identified in patients with Tourette syndrome (TS).
These data confirm histidine decarboxylase deficiency as a rare cause of TS and identify HA-DA interactions in the basal ganglia as an important locus of pathology.
A rare genetic form of Tourette syndrome due to L-histidine-decarboxylase mutation, with similar features in human and rodent, has inspired new research on functional anatomy of Tourette syndrome.
These data confirm histidine decarboxylase deficiency as a rare cause of TS and identify HA-DA interactions in the basal ganglia as an important locus of pathology.
No significant differences in genotypic and allele distribution between patients and controls for these three variants (P = 0.274, P = 1.000 and P = 0.632 for genotypic distribution, respectively; P = 0.143, P = 1.000 and P = 0.582 for allele distribution, respectively) were observed, suggesting variants in the HDC gene may play little or no role in TS susceptibility in Chinese Han population.
Intrathecally-administered histamine facilitates nociception through tachykinin NK1 and histamine H1 receptors: a study in histidine decarboxylase gene knockout mice.
We combined a case-control genetic association analysis and nuclear pedigrees transmission disequilibrium test (TDT) analysis to investigate the association between DRD3 gene rs6280 single nucleotide polymorphisms (SNPs) and TS in a Han Chinese population.
The Bal I and Msp I polymorphisms in the dopamine D3 receptor gene display, linkage disequilibrium with each other but no association with Tourette syndrome.
Controversial results possibly suggesting an association between Tourette's Syndrome (TS) and excess of homozygosity at a Msc I polymorphism in the Dopamine D3 receptor (DRD3) gene have recently been reported.
While DRD2 hypermethylation seems to be directly related to the neurobiology of TS that may lead to dopaminergic dysfunction resulting in enhanced thalamo-cortical movement-stimulating activity, DAT hypomethylation might reflect a secondary mechanism in order to compensate for increased dopaminergic signal transduction due to DRD2 hypermethylation.
Results demonstrated that Ning-dong granule effectively inhibited stereotype actions and Tourette's syndrome symptoms by promoting dopamine metabolism, reducing dopamine levels in the striatum, increasing homovanillic acid content in sera, and reducing mRNA expression of DRD2 in the striatum.
Our findings replicate the association of DRD2 and GTS, and are consistent with the proposed connection between the dopamine system and this complex neuropsychiatric disease.
NDG could increase the HVA content in sera (P<0.05), meanwhile downregulate the expression of DRD2 mRNA in striatum (P<0.05), and inhibit the stereotyped behaviors induced by Apo (P<0.01) in TS rats, the same effects with Hal.