Clinical subtypes in Parkinson's disease: the impact of MAPT haplotypes.

The H1 haplotype of the MAPT gene influences the risk of PD and has been related to the development of PDD. We evaluated the influence of MAPT haplotypes on the expression of motor features in PD patients. We genotyped, for the MAPT haplotypes H1 and H2, a sample of 181 PD patients with distinct clinical subtypes: tremor dominant and non-tremor dominant (NTD). Our results indicate that the MAPT haplotypes contribute to the expression of motor features of PD. H1 homozygous PD patients are significantly more likely to present a NTD phenotype, a clinical subtype characterized by widespread pathological degeneration, than H2 carriers.

Genetic polymorphism of Angiotensin-Converting Enzyme is not associated with the development of Parkinson's disease and of L-dopa-induced adverse effects.

Sporadic Parkinson's disease (PD) is a frequent neurodegenerative movement disorder. Both environmental and genetic factors have been studied in the etiology of PD. Among genetic factors, increasing evidences suggest that deletion/insertion (D/I) gene polymorphism of the angiotensin I-converting enzyme (ACE) may be involved in the pathogenesis of PD and in the occurrence of the adverse effects of chronic L-dopa therapy. We investigated this hypothesis by evaluating the frequency of the ACE gene D/I polymorphism in 120 Italian PD patients and 132 controls. Out of the 120 PD patients, 91 were under chronic L-dopa treatment. Our results revealed no difference in ACE I/D genotype (chi(2)=0.79, p=0.66) and allele (chi(2)=0.34, p=0.56) frequencies between PD and controls. We also failed to observe any significant association with the occurrence of L-dopa-induced adverse effects in long-term treated PD patients, thereby excluding the presence of an association between ACE I/D genotypes and the genetic susceptibility to PD and the development of adverse effect of chronic L-dopa therapy.