The authors conducted a case-control study of Parkinson's disease patients with and without visual hallucinations to investigate associations of the polymorphisms of the dopamine receptors D2 32806 C>T (Taq1A), D3 Ser9Gly and Msp1, D5 978T>C and dopamine transporter 3'-UTR 40 bp VNTR with visual hallucinations in Parkinson's disease.
To determine whether the frequency of dopamine receptor genetic variants and APOE alleles in patients with PD with and without chronic visual hallucinations resembles the pattern previously documented in patients with Alzheimer disease.
Moreover, patients with DRD1-48 GG and 62TT genotype displayed shorter time to VHs, whereas a longer time to VHs was found in subjects carrying the DRD4 CG alleles.
The clinical phenotype of PGRN mutation carriers was particular because of the wide range in onset age and the frequent occurrence of early apraxia (50%), visual hallucinations (30%), and parkinsonism (30%) during the course of the disease.
Moreover, patients with DRD1-48 GG and 62TT genotype displayed shorter time to VHs, whereas a longer time to VHs was found in subjects carrying the DRD4 CG alleles.
The authors conducted a case-control study of Parkinson's disease patients with and without visual hallucinations to investigate associations of the polymorphisms of the dopamine receptors D2 32806 C>T (Taq1A), D3 Ser9Gly and Msp1, D5 978T>C and dopamine transporter 3'-UTR 40 bp VNTR with visual hallucinations in Parkinson's disease.
These results suggest that, in Chinese, visual hallucinations in Parkinson's disease are associated with cholecystokinin -45C>T polymorphism, and this association was still observed in the presence of the cholecystokinin-A receptor TC/CC genotype, indicating a possible interaction of these two genes in the visual hallucinogenesis in Parkinson's disease.
The genotype of the TH tetranucleotide polymorphism was assessed in 204 German controls and 311 German alcohol-dependent subjects, including 63 alcoholics with a history of visual hallucinations during withdrawal delirium.
Furthermore, the PITX3 C allele carriers with PD had a poorer cognitive performance in the visuospatial domain (p<0.001) and a higher incidence of visual hallucinations.