"The types of mutations found in PARK2 are highly variable, such as point mutations, small deletions/insertions, and exonic rearrangement (either deletion or duplication), and have been reported in all exons of the gene.5 Notably, point mutations or small insertions/deletions, which are found in approximately 50% of Caucasian PD patients with PARK2 mutations, are infrequent in Asian populations.2,3,5,6,7,8,9,10,11 Although PARK2 mutations were initially found in patients with familial PD with an autosomal-recessive mode of inheritance, heterozygous mutations were also not uncommonly found in PD patients.1,2,3,12,13 "
[Show abstract][Hide abstract] ABSTRACT: Background and Purpose
There is some controversy regarding heterozygous mutations of the gene encoding parkin (PARK2) as risk factors for Parkinson's disease (PD), and all previous studies have been performed in non-Asian populations. Dosage mutation of PARK2, rather than a point mutation or small insertion/deletion mutation, was reported to be a risk factor for familial PD; dosage mutation of PARK2 is common in Asian populations.
We performed a gene-dosage analysis of PARK2 using real-time polymerase chain reaction for 189 patients with early-onset PD or familial PD, and 191 control individuals. In the case of PD patients with heterozygous gene-dosage mutation, we performed a sequencing analysis to exclude compound heterozygous mutations. The association between heterozygous mutation of PARK2 and PD was tested.
We identified 22 PD patients with PARK2 mutations (11.6%). Five patients (2.6%) had compound heterozygous mutations, and 13 patients (6.9%) had a heterozygous mutation. The phase could not be determined in one patient. Three small sequence variations were found in 30 mutated alleles (10.0%). Gene-dosage mutation accounted for 90% of all of the mutations found. The frequency of a heterozygous PARK2 gene-dosage mutation was higher in PD patients than in the controls.
Heterozygous gene-dosage mutation of PARK2 is a genetic risk factor for patients with early-onset or familial PD in Koreans.
"The locus is mapped to the telomeric region of the long-arm of chromosome 6. More than 100 mutations are associated with Parkin, ranging from point mutations and deletions to rearrangements and duplications.20,21 Clinically, affected families show parkinsonism similar to sporadic cases, except for the age of onset, which occurs from childhood to 40 years and is rarely seen in individuals over 50 years of age.22 "
[Show abstract][Hide abstract] ABSTRACT: Discovering genes following Medelian inheritance, such as autosomal dominant-synuclein and leucine-rich repeat kinase 2 gene, or autosomal recessive Parkin, P-TEN-induced putative kinase 1 gene and Daisuke-Junko 1 gene, has provided great insights into the pathogenesis of Parkinson's disease (PD). Genes found to be associated with PD through investigating genetic polymorphisms or via the whole genome association studies suggest that such genes could also contribute to an increased risk of PD in the general population. Some environmental factors have been found to be associated with genetic factors in at-risk patients, further implicating the role of gene-environment interactions in sporadic PD. There may be confusion for clinicians facing rapid progresses of genetic understanding in PD. After a brief review of PD genetics, we will discuss the insight of new genetic discoveries to clinicians, the implications of ethnic differences in PD genetics and the role of genetic testing for general clinicians managing PD patients.
"However, when the entire brain was analyzed, increased protein oxidation occurred in parkin KO mice at 18–20 months  and lipid peroxidation occurred in aged parkin KO mice . Mutations in the parkin gene [64,65] are the most common genetic risk factors for early-onset PD [66–68] with age at onset ≤ 45 or 55 years. Cases with parkin mutations with age at onset > 70 years have also been reported [68–70]. "
[Show abstract][Hide abstract] ABSTRACT: S.V.M.); firstname.lastname@example.org (B.-W.K.); email@example.com (S.K.); firstname.lastname@example.org (I.S.K.) Abstract: Free radical production and their targeted action on biomolecules have roles in aging and age-related disorders such as Parkinson's disease (PD). There is an age-associated increase in oxidative damage to the brain, and aging is considered a risk factor for PD. Dopaminergic neurons show linear fallout of 5–10% per decade with aging; however, the rate and intensity of neuronal loss in patients with PD is more marked than that of aging. Here, we enumerate the common link between aging and PD at the cellular level with special reference to oxidative damage caused by free radicals. Oxidative damage includes mitochondrial dysfunction, dopamine auto-oxidation, α-synuclein aggregation, glial cell activation, alterations in calcium signaling, and excess free iron. Moreover, neurons encounter more oxidative stress as a counteracting mechanism with advancing age does not function properly. Alterations in transcriptional activity of various pathways, including nuclear factor erythroid 2-related factor 2, glycogen synthase kinase 3β, mitogen activated protein kinase, nuclear factor kappa B, and reduced activity of superoxide dismutase, catalase and glutathione with aging might be correlated with the increased incidence of PD.
International Journal of Molecular Sciences 08/2012; 13(8):10478-10504. DOI:10.3390/ijms130810478 · 2.86 Impact Factor
Data provided are for informational purposes only. Although carefully collected, accuracy cannot be guaranteed. The impact factor represents a rough estimation of the journal's impact factor and does not reflect the actual current impact factor. Publisher conditions are provided by RoMEO. Differing provisions from the publisher's actual policy or licence agreement may be applicable.