Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0030567 (Parkinson's disease)
 63,064 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The frequency of fifteen genotypes of CYP2D6 (debrisoquine 4-hydroxylase) in 53 patients with Parkinson's disease was determined by the polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) analyses and compared with the findings in 72 healthy controls. The commonest mutant allele, CYP2D6B, was twice as frequent among patients as in controls, with an approximate relative risk ratio of 2.70 (95% confidence interval 1.14-6.41; p = 0.0063) for subjects homozygous or heterozygous for this allele.
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PMID:Mutant debrisoquine hydroxylation genes in Parkinson's disease. 134 52

The pathogenesis of Parkinson's disease may be influenced by genetic and environmental factors. Cytochrome P450 mono-oxygenases help to protect against toxic environmental compounds and individual variations in cytochrome P450 expression might, therefore, influence susceptibility to environmentally linked diseases. The frequency of mutant CYP2D6 alleles was studied in 229 patients with Parkinson's disease and 720 controls. Individuals with a metabolic defect in the cytochrome P450 CYP2D6-debrisoquine hydroxylase gene with the poor metaboliser phenotype had a 2.54-fold (95% Cl 1.51-4.28) increased risk of Parkinson's disease. Determination of CYP2D6 phenotype and genotype may help to identify those at greatest risk of Parkinson's disease and may also help to identify the environmental or metabolic agents involved in the pathogenesis of this disease.
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PMID:Debrisoquine hydroxylase gene polymorphism and susceptibility to Parkinson's disease. 791 91

Molecular genetic studies of the cytochrome P450 system enzyme CYP2D6, which hydroxylates debrisoquine, have indicated an excess of mutant alleles in large series of patients with Parkinson's disease (PD) when compared with controls. We have investigated CYP2D6 polymorphism in 91 patients with multiple system atrophy (MSA) in order to determine if this finding is specific to PD or if there is similar evidence of genetic susceptibility to neurotoxicity in MSA. The distribution of CYP2D6 alleles was not significantly different between MSA patients and controls, and there were fewer poor metabolisers in the MSA group than in the control group.
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PMID:CYP2D6-debrisoquine hydroxylase gene polymorphism in multiple system atrophy. 765 42

The frequency of five cytochrome P450IID6 allelic variants was studied in deoxyribonucleic acid from 123 patients with Parkinson's disease and 150 healthy volunteers. This was achieved by the use of mutation-specific polymerase chain reaction and restriction fragment length polymorphism. The analyses of the CYP2D6 genotype revealed no evidence for a higher prevalence of poor metabolizers among patients with Parkinson's disease. However, increased frequency of patients with Parkinson's disease with the genotype CYP2D6wt/CYP2D6B was observed. This is attributable exclusively to subjects with early onset of the disease (28 to 49 years), with a relative risk ratio of 4.16 (95% confidence limits, 2.0 to 8.3; p < 0.0005). The subjects who had late-onset Parkinson's disease (> or = 50 years) had genotypes and CYP2D6 allele frequencies similar to the healthy subjects. This indicates that the oxidative polymorphism is related to early-onset but not to late-onset Parkinson's disease. A different influence of CYP2D6 genotype on the risk of development of Parkinson's disease is observed in Spaniards, compared with previous findings in British subjects. These results suggest the combined effect of environmental toxins and CYP2D6 in the cause of Parkinson's disease.
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PMID:Association between the oxidative polymorphism and early onset of Parkinson's disease. 769 46

Polymorphisms in many xenobiotic metabolizing enzymes occur leading to variation in the level of enzyme expression in vivo. Enzymes showing such polymorphisms include the cytochrome P450 enzymes CYP1A1, CYP1A2, CYP2A6, CYP2D6, and CYP2E1 and the phase two metabolism enzymes glutathione S-transferase MI (GSTMI) and arylamine N-acetyltransferase 2 (NAT2). In the past, these polymorphisms have been studied by phenotyping using in vivo administration of probe drugs. However, the mutations which give rise to several of these polymorphisms have now been identified and genotyping assays for polymorphisms in CYP1A1, CYP2A6, CYP2D6, CYP2E1, GSTMI, and NAT2 have been developed. Specific phenotypes for several of the polymorphic enzymes have been associated with increased susceptibility to malignancy, particularly lung and bladder cancer, and Parkinson's disease. These associations are likely to be due to altered activation or detoxication of chemicals initiating these diseases, including components of tobacco smoke and neurotoxins. The substrate specificity and tissue distribution of polymorphic enzymes implicated in disease causation discussed with particular reference to previously described disease-phenotype associations.
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PMID:Genotyping for polymorphisms in xenobiotic metabolism as a predictor of disease susceptibility. 769 86

Approximately one-fourth of neuropathologically confirmed cases of Alzheimer's disease (AD) also have brainstem and neocortical Lewy bodies, constituting a Lewy body variant of AD. Because Lewy bodies are a pathologic hallmark of Parkinson's disease (PD), this subpopulation of AD subjects may have the same risk factors as PD subjects. Analyses of the cytochrome P450 CYP2D6-debrisoquine 4-hydroxylase mutant B allele, a susceptibility gene for PD, revealed a higher representation of this allele in the Lewy body variant of AD than in pure AD or non-AD without Lewy bodies.
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PMID:The CYP2D6B mutant allele is overrepresented in the Lewy body variant of Alzheimer's disease. 781 42

Cytochrome P450 CYP2D6 polymorphism is an autosomal recessive trait associated with impaired debrisoquine metabolism in 5-10% of caucasian populations. This polymorphism has been associated with susceptibility to Parkinson's disease, bladder cancer, various forms of leukemia and possibly melanoma. In many other cancer forms, the data remained contradictory due to the technical limitations for identifying affected individuals (poor metabolizers). A recently developed polymerase chain reaction-based assay allows convenient screening of approximately 80% of known mutations. We have tested brain tumors correlated with chromosome 22 deviations for genetic polymorphism in the cytochrome P450 CYP2D6 locus localized on chromosome 22q13. Thirty-one meningioma samples were analyzed and the observed frequency of heterozygotes and homozygotes for the G to A mutation did not deviate significantly from the distribution in a normal population. These data are comparable to previous observations in for example breast and colon cancer and indicate that the CYP2D6 locus on chromosome 22q13 is not involved in the pathogenesis of meningiomas.
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PMID:Debrisoquine hydroxylase gene polymorphism in meningioma. 784 77

Genetic polymorphism of the CYP2D6 gene [phenotypically individuals are either poor metabolizers (PM) or extensive metabolizers (EM)] has been reported to be associated with susceptibility to Parkinson's disease. We analyzed CYP2D6 genes from Japanese patients and controls, and found that EM/PM polymorphism is not a suitable marker for populations with a low PM frequency. However, a novel mutant highly associated with Parkinson's disease was discovered. The mutation was located at the HhaI site in exon 6 and changed a conserved amino acid residue, Arg296, to Cys296. The risk factor for the mutant homozygote was 5.56 (95% CI, 1.30-23.82). These results suggest that the HhaI polymorphism in the CYP2D6 gene is a part of the molecular basis of Parkinson's disease.
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PMID:A novel cytochrome P-450IID6 mutant gene associated with Parkinson's disease. 790 97

Linkage studies were performed in three families (A, B, and C) with autosomal dominantly inherited parkinsonism affecting multiple members in three generations. Affected individuals exhibited the cardinal signs and symptoms of Parkinson's disease, with a mean age of onset of 51, 62, and 61 years in Families A, B, and C, respectively. Parkinsonian symptoms responded to L-dopa treatment, and an [18F]6-fluoro-L-dopa positron emission tomography scan in 1 affected member of Family B showed decreased striatal uptake typical of Parkinson's disease. Ancestors of all three families were traced to a small region in northern Germany and southern Denmark, suggesting the possibility of a common mutation. Linkage studies were performed with polymorphic markers associated with the following candidate genes: the genes for glutathione peroxidase (GPX1, 3q11), tyrosine hydroxylase (TH, 11p15.5), brain-derived neurotrophic factor (BDNF, 11p14), catalase (CAT, 11p13), amyloid precursor protein (APP, 21q21), copper-zinc superoxide dismutase (SOD1, 21q21), and debrisoquin 4-hydroxylase (CYP2D6, 22q13.1). Summed lod scores for all families excluded linkage to the genes GPX1, TH, APP, SOD1, and CYP2D6, as well as to the chromosomal region containing the genes CAT and BDNF. If families were analyzed individually, exclusion was possible for two (Family A), six (Family B), and five (Family C) of the seven candidate genes. There was strong evidence against linkage for the remaining loci in all families analyzed individually, except for TH, which was uninformative in Families A and B, and CYP2D6, which gave slightly positive pairwise lod scores in Family A. Our results indicate that the candidate genes investigated are not involved in the etiology of parkinsonism in these families.
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PMID:Genetic linkage studies in autosomal dominant parkinsonism: evaluation of seven candidate genes. 791 97

Certain anticonvulsant drugs require N-acetylation as a major route of metabolic clearance. Single point mutations of the polymorphic N-acetyltransferase gene (pNAT) are the primary cause for impaired drug acetylation. Pharmacokinetic parameters are altered in slow acetylator phenotypes and this may compromise drug safety. Genetic analysis of allelic frequencies of individual pNAT genotypes point to significant increases in carriers of the S1/wt and S3/wt (P < 0.05) allele and a significant reduction in carriers of the S2/S2 (P < 0.01) allele, when control and epileptic patients are compared. Furthermore, the presumed link between the cytochrome P450 CYP2D6 polymorphism and the pathogenesis of Parkinson's disease led us to investigate, whether a similar relationship can be expected for other CNS disorders. Our findings indicate that poor metabolizers are more frequent (P < 0.05) amongst epileptic patients, when compared with a control population. An estimate of the odds ratio may suggest an increased risk [95% CI (confidence interval) 1.043-4.734] of up to 5-fold in epileptic patients carrying this mutation. This provides further evidence for a potential link between the debrisoquine hydroxylase gene polymorphism and CNS disorder and therefore warrants further study.
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PMID:pNAT and CYP2D6 gene polymorphism in epileptic patients. 798 Jun 40


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