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)

A neurodegenerative disorder, fragile X-associated tremor/ataxia syndrome (FXTAS), occurs in some older men carrying a small CGG repeat expansion (pre-mutation) in the FMR1 gene. We surveyed a sample of older pre-mutation males to estimate the prevalence and spectrum of neurological involvement. Twelve pre-mutation males aged 50-82 years and 11 age-matched normal controls ascertained in an unbiased manner were included in a neurological assessment that also used standard scales for tremor (Clinical Rating Scale for Tremor), ataxia (International Cooperative Ataxia Rating Scale, ICARS) and parkinsonian signs (Unified Parkinson's Disease Rating Scale). Axial FLAIR images of the brain, and neuropsychological and molecular tests were also conducted in pre-mutation carriers. The neurological disorder meeting all the criteria for diagnosis of 'definite' to 'possible' FXTAS occurred in five of 12 pre-mutation carriers (41.7%), and this prevalence was significantly higher compared with normal controls (0%). The ataxia (ICARS) score and the sum of all three tremor/ataxia scores were significantly higher in pre-mutation carriers than in controls, and mRNA was elevated in all but one carrier, but did not correlate with the degree of neurological involvement. In conclusion, the findings provide further evidence that the pre-mutation allele of FMR1 is a significant cause of late-onset neurodegeneration, presenting with a broad spectrum of clinical manifestations.
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PMID:Evidence for, and a spectrum of, neurological involvement in carriers of the fragile X pre-mutation: FXTAS and beyond. 1581 Oct 8

Carriers of expanded alleles of the fragile X mental retardation (FMR1) gene may display parkinsonism, cognitive decline, and behavioral changes. The authors screened 2 male groups of patients affected with Parkinson's disease (PD) (n = 137). One group (n = 56) was followed longitudinally for up to 12 years. Length of CGG repeats in PD patients was compared with healthy controls (n = 310). In addition, the association of the number of CGG repeats with cognitive decline or hallucinations was studied in the longitudinally followed PD group. The authors found no repeats in the premutation range (55-200 CGG repeats) and no significant difference in the proportion of intermediate-size (41-54 CGG repeats) carriers between the PD and the control groups. Using linear regression, the number of CGG repeats was not related to motor or cognitive progression. However, the marked cognitive decline in 2 patients carrying intermediate-size alleles points to a possible association. More studies with larger PD samples are warranted.
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PMID:FMR1 alleles in Parkinson's disease: relation to cognitive decline and hallucinations, a longitudinal study. 1754 78

Premutation carriers of repeat expansions in the fragile X mental retardation (FMR1) gene develop kinetic tremor and ataxia or the 'fragile X associated tremor/ataxia syndrome' (FXTAS). Affected FMR1 premutation carriers also have parkinsonism, but have not been reported to meet criteria for Parkinson disease. This case series illustrates that some patients who are FMR1 premutation carriers may appear by history and examination to have idiopathic Parkinson disease. Based on previous studies, it is likely that the genetic mutation and parkinsonism are associated. Although screening all PD patients is likely to be low yield, genetic testing of FMR1 in individuals with PD and a family history of fragile X syndrome, autism or developmental delay, or other related FMR1 phenotypes is warranted.
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PMID:Parkinsonism in FMR1 premutation carriers may be indistinguishable from Parkinson disease. 1856 83

The FXTAS syndrome (Fragile X-associated tremor/ataxia syndrome) is a specific neurodegenerative syndrome affecting subjects carrying a premutation of the FMR1 (fragile X mental retardation 1) gene. It affects mainly men with the premutation and aged more than 50 years. This syndrome is separate and distinct from the fragile X syndrome. The FXTAS syndrome remains underestimated today. It should be considered in patients older than 50 years with tremors and cerebellar ataxia, especially when Parkinson disease or cognitive disorders are present or when there is a family history of infertility, early menopause, or mental retardation. In these patients, hyperintense signals of mid-cerebellar peduncle images on T2 and FLAIR MRI justify genetic testing for the FMR1 premutation.
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PMID:[Tremor/ataxia syndrome related to Fragile X premutation]. 1941 33

In the past decade, a number of genetic causes of parkinsonism have been identified. As a consequence, clinicians have to consider an increasing range of differential diagnoses when confronted with a patient with parkinsonism with a positive family history. While well-established monogenic forms with PARK acronyms have been reviewed extensively, less emphasis has been placed on other inherited conditions that may also present with signs of parkinsonism or even mimic idiopathic Parkinson's disease clinically. In this review, we focus on three different scenarios in patients with an overall early age of onset of parkinsonism: (i) atypical features in patients with mutations in one of the "PARK" genes; (ii) classical parkinsonism due to mutations in "other than-PARK" genes or yet other genes where parkinsonism may be a well-recognized, concomitant, or even an isolated feature; (iii) atypical parkinsonism in other genetic disorders which are, however, typically characterized by features other than parkinsonism. Atypical features in patients from Group I include, for example, a slower disease course (PARK2, PARK6, PARK7) or dementia (PARK1/4, PARK14). Conditions in Group II have been designated by a DYT or SCA acronym (for example, DYT5 or SCA3) and also include patients with heterozygous GBA mutations, mitochondrial gene mutations. Group III comprises mutations in the FMR1, MAPT, GRN, ATP7B, PANK2, FBXO7, CHAC, FTL1, Huntingtin, JPH3 genes, and a number of even rarer, miscellaneous conditions.
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PMID:Hereditary parkinsonism: Parkinson disease look-alikes--an algorithm for clinicians to "PARK" genes and beyond. 1973 92

Fragile X-associated tremor/ataxia syndrome (FXTAS) affects older males carrying premutation, that is, expansions of the CGG repeat (in the 55-200 range), in the FMR1 gene. The neurological changes are linked to the excessive FMR1 messenger RNA (mRNA), becoming toxic through a 'gain-of-function'. Because elevated levels of this mRNA are also found in carriers of the smaller expansion (grey zone) alleles, ranging from 40 to 54 CGGs, we tested for a possible role of these alleles in the origin of movement disorders associated with tremor. We screened 228 Australian males affected with idiopathic Parkinson's disease and other causes of parkinsonism recruited from Victoria and Tasmania for premutation and grey zone alleles. The frequencies of either of these alleles were compared with the frequencies in a population-based sample of 578 Guthrie spots from consecutive Tasmanian male newborns (controls). There was a significant excess of premutation carriers (Fisher's exact test p = 0.006). There was also a more than twofold increase in grey zone carriers in the combined sample of the Victorian and Tasmanian cases, with odds ratio (OR ) = 2.36, and 95% confidence intervals (CI): 1.20-4.63, as well as in Tasmanian cases only (OR = 2.33, 95% CI: 1.06-5.13), compared with controls. The results suggest that the FMR1 grey zone alleles, as well as premutation alleles, might contribute to the aetiology of disorders associated with parkinsonism.
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PMID:Small CGG repeat expansion alleles of FMR1 gene are associated with parkinsonism. 1979 83

FXTAS (fragile X-associated tremor/ataxia syndrome) is a late-onset neurodegenerative disorder that affects individuals who are carriers of premutation expansions (55-200 CGG repeats) in the 5' untranslated region of the FMR1 (fragile X mental retardation 1) gene. The role of MD (mitochondrial dysfunction) in FXTAS was evaluated in fibroblasts and brain samples from premutation carriers with and without FXTAS symptoms, with a range of CGG repeats. This study resulted in several important conclusions: (i) decreased NAD- and FAD-linked oxygen uptake rates and uncoupling between electron transport and synthesis of ATP were observed in fibroblasts from premutation carriers; (ii) a lower expression of mitochondrial proteins preceded both in age and in CGG repeats the appearance of overt clinical involvement; (iii) the CGG repeat size required for altered mitochondrial protein expression was also smaller than that required to produce brain intranuclear inclusions from individuals with the premutation who died, suggesting that MD is an incipient pathological process occurring in individuals who do not display overt features of FXTAS; and (iv) on the basis of the CGG repeats, MD preceded the increase in oxidative/nitrative stress damage, indicating that the latter is a late event. MD in carriers of small CGG repeats, even when the allele size is not sufficient to produce FXTAS, may predispose them to other disorders (e.g. Parkinson's disease) that are likely to involve MD, and to environmental stressors, which may trigger the development of FXTAS symptoms. Detection of MD is of critical importance to the management of FXTAS, since it opens up additional treatment options for this disorder.
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PMID:Evidence of mitochondrial dysfunction in fragile X-associated tremor/ataxia syndrome. 2051 37

Examples of white matter hyperintensities (wmh) on magnetic resonance images in a basis pontis are presented in two male carriers, each of whom carry a small CGG expansion fragile X mental retardation (FMR1) allele. One carried a premutation (PM) allele of 85 CGG repeats and the other, a gray zone (GZ) allele of 47 repeats. Both were originally diagnosed with idiopathic Parkinson's disease (iPD). Similar changes are also shown in one PM carrier of 99 repeats affected with mild tremor and imbalance, who was ascertained through a fragile X syndrome family. These examples draw attention to the occurrence of wmh in a basis pontis in the carriers of small CGG expansions presenting with tremor and ataxia. Moreover, the presence of this change in GZ, as well as PM, allele carriers originally diagnosed with iPD supports our earlier suggestion that both these alleles may contribute to the neurodegenerative changes in this disorder which, in the examples presented, have been reflected by wmh, most prominent in the cerebellar peduncles and/or pontine area.
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PMID:White matter changes in basis pontis in small expansion FMR1 allele carriers with parkinsonism. 2144 59

We recently reported a significant increase in the frequency of carriers of grey zone (GZ) alleles of FMR1 gene in Australian males with Parkinson's disease (PD) from Victoria and Tasmania. Here, we report data comparing an independent sample of 817 PD patients from Queensland to 1078 consecutive Australian male newborns from Victoria. We confirmed the earlier finding by observing a significant excess of GZ alleles in PD (4.8%) compared to controls (1.5%). Although both studies provided evidence in support of an association between GZ-carrier status and increased risk for parkinsonism, the existing evidence in the literature from screening studies remains equivocal and we discuss the need for alternative approaches to resolve the issue.
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PMID:New evidence for, and challenges in, linking small CGG repeat expansion FMR1 alleles with Parkinson's disease. 2319 93

While FMR1 is silenced in Fragile X syndrome (FXS) patients carrying the full mutation, its expression is elevated (2-8 fold) in premutated individuals. These people may develop the Fragile X-associated Tremor/Ataxia syndrome (FXTAS), a late onset neurodegenerative disorder characterized by ataxia and parkinsonism. In addition, people carrying the premutation can be affected by a set of neurological and behavioral disorders during young age. Problems of memory have been detected in these patients as well as in the mouse models for FXTAS. To date little is known concerning the metabolism of FMR1 mRNA, notwithstanding the importance of the finely tuned regulation of the expression of this gene. In the present study, we identified three microRNAs that specifically target the 3' UTR of FMR1 and can modulate its expression throughout the brain particularly at the synapse where their expression is very high. The expression level of miR-221 is reduced in synaptosomal preparations of young FXTAS mice suggesting a general deregulation of transcripts located at the synapse of these mice. By transcriptome analysis, we show here a robust deregulation of the expression levels of genes involved in learning, memory and autistic behavior, Parkinson disease and neurodegeneration. These findings suggest the presence of a synaptopathy in these animals. Interestingly, many of those deregulated mRNAs are target of the same microRNAs that modulate the expression of FMR1 at the synapse.
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PMID:The 3' UTR of FMR1 mRNA is a target of miR-101, miR-129-5p and miR-221: implications for the molecular pathology of FXTAS at the synapse. 2339 Jan 34


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