Apolipoprotein E epsilon4 allele in familial and sporadic Parkinson’s disease. Neurosci Lett

Experimental Unit, Donostia Hospital, San Sebastián, Spain.
Neuroscience Letters (Impact Factor: 2.03). 11/2006; 406(3):235-9. DOI: 10.1016/j.neulet.2006.07.037
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Parkinson's disease (PD) is the second most common age-related neurodegenerative disease after Alzheimer's disease (AD). Common risk factors for both diseases have been explored to study potential etiologic interactions between these two neurodegenerative disorders. The APOE epsilon4 allele, previously associated with AD, has also been associated with risk of PD and with the presence of some clinical features in PD patients. However, the role of APOE epsilon4 allele in risk of PD remains unclear. We studied the distribution of APOE alleles in 276 unrelated familial and sporadic PD patients and in 212 controls. Patients and controls were classified by ethnicity. No genetic heterogeneity between Basques and people from other regions of Spain was found. No significant differences in APOE allele distribution between PD patients and controls were found; however, lower epsilon4 allele frequency was observed when the sporadic PD group was analyzed separately. By contrast, an increase in epsilon4 allele frequency was found in familial PD patients with cognitive decline. We conclude that the APOE epsilon4 allele may be associated with the risk of developing PD in isolated cases and that it is linked to the presence of cognitive decline in familial PD in our sample.

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    • "with inconsistent results. Most studies reported a null association, although few reported either a significantly lower (1997, Blazquez, et al., 2006) or a significantly higher risk for PD among ε4 carriers (Ghebremedhin, et al., 2006, Papapetropoulos, et al., 2007). Most of these studies were included in two recently published meta-analyses: first by Huang et al. (Huang, et al., 2004), and then updated by Williams- Gray et al. (Williams-Gray, et al., 2009) In both reports, ApoE ε4 was not associated with a higher risk of PD. "
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    ABSTRACT: We examined apolipoprotein E (ApoE) genotypes in relation to Parkinson's disease (PD) among 786 cases and 1537 controls, all non-Hispanic Caucasians. Odds ratios (ORs) and 95% confidence intervals (CIs) were derived from multivariate logistic regression models, adjusting for year of birth, sex, smoking status, daily caffeine intake, and family history of PD. Compared with participants with ApoE ε33, ε4 carriers (ε34/ε44) had significantly lower odds for having PD (OR, 0.75; 95% CI, 0.59-0.94; p = 0.01), whereas ε2 carriers (ε23/ε22) did not (OR, 0.95; 95% CI, 0.73-1.24; p = 0.71). Subgroup analyses showed similar results. In addition, we conducted a meta-analysis which confirmed our primary findings (ε34/ε44 vs. ε33: OR, 0.90; 95% CI, 0.81-0.99; p = 0.024 and ε23/ε22 vs. ε33: OR, 1.10; 95% CI, 0.97-1.23; p = 0.13). In PD patients, the prevalence of dementia appeared to be higher among ε4 carriers (compared with ε33: OR, 1.59; 95% CI, 0.98-2.58; p = 0.06), but lower among ε2 carriers (OR, 0.75; 95% CI, 0.40-1.42; p = 0.38), although neither test was statistically significant. Our study suggested that the ApoE ε4 allele may be associated with a lower PD risk among non-Hispanic Caucasians.
    Neurobiology of aging 07/2011; 32(11):2106.e1-6. DOI:10.1016/j.neurobiolaging.2011.05.016 · 5.01 Impact Factor
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    • "Apo E receptors act as signaling molecules in neurons, altering the phosphorylation mechanism of several proteins after extracellular ligand binding and affecting neurite outgrowth, synapse formation and neuronal migration [10]. The results observed in this study regarding the low frequency of the ε4/ε4 alleles (1%) and no association observed in patients with idiopathic PD; agree with the findings observed by Bí azquez et al. [23]; in a sample Spanish population of 276 unrelated, familial and sporadic PD patients and in 212 controls, the distribution of Apo E alleles was studied and no significant differences in were found; however, they observed a lower ε4 allele frequency in the sporadic PD group. In contrast, an increase in ε4 allele frequency was found in familial PD patients with cognitive decline. "
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    ABSTRACT: The association of the apolipoprotein (Apo E) -epsilon4 allele to neurodegenerative diseases such as Parkinson's disease (PD) has been analyzed in several studies. This association has been identified by amyloid deposits and neurofibrillary tangles in the brains of patients with neurodegenerative diseases. In this study the possible relationship between Apo E alleles and PD patients was analyzed in 105 patients with PD and 107 healthy controls from a Mexican population. Allele analysis in PD vs. controls was: epsilon2 in 6% and 2.3%, respectively; epsilon3 in 73% and 88.3%; and epsilon4} in 21% and 9.4%. The epsilon3 allele showed a protective risk effect with an Odds ratio (OR) of 0.36 (95%CI 0.20-0.61) and p < 0.05; contrary results were observed for the epsilon4 allele, which showed an increased risk for PD, with an OR of 2.57(95% CI 1.42-4.79) and p < 0.05. Upon multivariate analysis showed PD risk was evident in patients who were carriers of the genotype epsilon3/epsilon4; age group (fifty or more years) and had exposure to pesticides and solvents (p < 0.05). The epsilon3/epsilon3}; epsilon3/epsilon4 genotypes of the Apo E, were positively associated with sporadic PD.
    Disease markers 12/2009; 27(5):225-30. DOI:10.3233/DMA-2009-0667 · 1.56 Impact Factor
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    ABSTRACT: Hypokinesia, rigidity, tremor, and postural instability are the cardinal symptoms of Parkinson s disease (PD). Since these symptoms are not specific to PD the diagnosis may be uncertain in early PD. Etiology and pathogenesis of PD remain unclear. There is no neuroprotective therapy. Genetic findings are expected to reveal metabolic routes in PD pathogenesis and thereby eventually lead to therapeutic innovations. In this thesis, we first aimed to study the usefulness and accuracy of 123I-b-CIT SPECT in the diagnosis of PD in a consecutive clinic-based material including various movement disorders. We subsequently a genetic project to identify genetic risk factors for sporadic PD using a candidate gene approach in a case-control setting including 147 sporadic PD patients and 137 spouse controls. Dopamine transporter imaging by 123I-b-CIT SPECT could distinguish PD from essential tremor, drug-induced parkinsonism, dystonia and psychogenic parkinsonism. However, b-CIT uptake in Parkinson plus syndromes (PSP and multiple system atrophy) and dementia with Lewy bodies was not significantly different from PD. 123I-b-CIT SPECT could not reliably differentiate PD from vascular parkinsonism. 123I-b-CIT SPECT was 100% sensitive and specific in the diagnosis of PD in patients younger than 55 years but less specific in older patients, due to differential distribution of the above conditions in the younger and older age groups. 123I-b-CIT SPECT correlated with symptoms and detected bilateral nigrostriatal defect in patients whose PD was still in unilateral stage. Thus, in addition to as a differential diagnostic aid, 123I-b-CIT SPECT may be used to detect PD early, even pre-symptomatically in at-risk individuals. 123I-b-CIT SPECT was used to aid in the collection of patients to the genetic studies. In the genetic part of this thesis we found an association between PD and a polymorphic CAG-repeat in POLG1 gene encoding the catalytic subunit of mitochondrial polymerase gamma. The CAG-repeat encodes a polyglutamine tract (polyQ), the two most common lengths of which are 10Q (86-90%) and 11Q. In our Finnish material, the rarer non-10Q or non-11Q length variants (6Q-9Q, 12Q-14Q, 4R+9Q) were more frequent in patients than in spouse controls (10% vs. 3.5 %, p=0.003), or population controls (p=0.001). Therefore, we performed a replication study in 652 North American PD patients and 292 controls. Non-10/11Q alleles were more common in the US PD patients compared to the controls but the difference did not reach statistical significance (p=0.07). This larger data suggested our original definition of variant length allele might need reconsideration. Most previous studies on phenotypic effects of POLG1 polyQ have defined 10Q as the only normal allele. Non-10Q alleles were significantly more common in patients compared to the controls (17.3% vs. 12.3 %, p= 0.005). This association between non-10Q length variants and PD remained significant when compared to a larger set of 1541 literature controls (p=0.00005). In conclusion, POLG1 polyQ alleles other than 10Q may predispose to PD. We did not find association between PD and parkin or DJ-1, genes underlying autosomal recessive parkinsonism. The functional Val158Met polymorphism, which affects the catalytic effect of COMT enzyme, and another coding polymorphism in COMT were not associated with PD in our patient material. The APOE e2/3/4 polymorphism modifies risk for Alzheimer s disease and prognosis of for example brain trauma. APOE promoter and enhancer polymorphisms 219G/T and +113G/C, and APOE e3 haplotypes, have also been shown to modify the risk of Alzheimer s disease but not reported in PD. No association was found between PD and APOE e2/3/4 polymorphism, the promoter or enhancer polymorphisms, or the e3 haplotypes. Parkinsonin tauti (PT) on vanhemmalla iällä ilmenevä neurodegeneratiivinen sairaus, jonka pääoireet ovat vapina, jäykkyys, liikkeiden hitaus ja tasapainon ja asennonsäätelyn häiriö. Nämä oireet eivät ole PT:lle spesifisiä, ja diagnoosi on alkuvaiheessa usein epävarma. Taudin syntymekanismi on edelleen epäselvä eikä taudin etenemiseen vaikuttavaa lääkitystä ole. Geneettisten riskitekijöiden löytämisen toivotaan auttavan taudin mekanismien selvittämisessä ja johtavan terapeuttisiin innovaatioihin. Tässä väitöskirjatyössä selvitettiin ensin dopamiinitransportterien (DAT) gammakuvauksen (123I-b-CIT SPECT) hyödyllisyyttä kliinisessä aineistossa, jossa oli useita eri liikehäiriöitä sairastavia potilaita. DAT tiheys kuvastaa nigrostriataalisten neuronien määrää, minkä vuoksi PT-potilailla nähdäänkin 123I-b-CIT SPECT:ssä alentunut DAT-tiheys. 123I-b-CIT SPECT todettiin erottavan PD-potilaat essentielliä tremoria, lääkeaineparkinsonismia ja psykogeenistä parkinsonismia sairastavista. Toisaalta menetelmä ei erotellut Parkinson + -oireyhtymiä tai Lewyn kappale dementiaa sairastavia potilaita PD-potilaista. 123I-b-CIT SPECT ei myöskään varmuudella auta vaskulaarisen parkinsonismin ja PT:n erotusdiagnostiikassa. 123I-b-CIT SPECT yli 100 % sensitiivinen ja spesifinen PD-diagnoosissa alle 55-vuotiaassa aineistossa mutta vähemmän spesifinen vanhemmassa potilasaineistossa yllämainittujen diagnoosien ikäjakaumasta johtuen. 123I-b-CIT SPECT korreloi oireiden vakavuuden kanssa ja havaitsi bilateraalisen DAT-tiheyden aleneman jo siinä vaiheessa kun potilaan oireet vielä rajoittuivat toiselle puolelle. 123I-b-CIT SPECTiä voitaneenkin käyttää, paitsi erotusdiagnostiikassa, myös etsimään PT:a riskihenkilöiltä jo motorisia oireita edeltävässä vaiheessa. 123I-b-CIT SPECTiä käytettiin apuna potilasvalinnassa työn geneettiseen osioon. Geneettisessa potilas-verrokkiaineistossa oli 147 sporadista suomalaista parkinsonpotilasta ja 137 puolisoa kontrolleina. Mitokondriaalista polymeraasi gamma-entsyymiä koodaavan POLG1 geenin eksonissa 2 olevasta polymorfisesta CAG-toistojaksosta löytyi todennäköinen PT:n riskitekijä. Tämä CAG-toisto koodaa polyglutamiiniketjua (polyQ), jonka yleisimmät pituudet ovat 10Q (86-90%) ja 11Q. Suomalaisilla potilailla polyQ-alleellit, jotka olivat lyhyempiä kuin 10Q tai pidempiä kuin 11Q (non-10/11Q) olivat yleisempiä kuin kontrolleilla (10 vs. 3.5 %, p= 0.003). Teimme replikaatiotutkimuksen pohjoisamerikkalaisessa aineistossa (652 PT-potilasta, 292 kontrollia). Non-10/11Q alleelit olivat potilailla yleisempiä kuin kontrolleilla, mutta ei merkittävästi (p=0.07). Monissa aiemmissa POLG1 polyQ:ta muissa ilmiasuissa tutkineissa töissä ainoastaan 10Q alleelia on pidetty normaalina alleelina. Non-10Q-alleelit olivat selvästi yleisempiä PT-potilailla kuin kontrolleilla (17.3% vs. 12.3 %, p= 0.005) tai 1541 kirjallisuuskontrollilla (p=0.00005). POLG1 geenin polyQ-jakson non-10Q pituusvariantit näyttävät lisäävän PT:n riskiä. Aineistossamme ei löytynyt assosiaatiota DJ-1 tai parkin geeneihin, joiden mutaatiot aiheuttavat resessiivisen varhain alkavan PT:n. Myöskään COMT-entsyymin aktiivisuuteen vaikuttava COMT Val158Met substituutio tai Ala72Ser eivät olleet yhteydessä PT:n riskiin. APOE e2/3/4 polymorfismin tiedetään vaikuttavan mm. Alzheimerin taudin riskiin ja aivovamman ennusteeseen, samoin APOE promoottorialueen polymorfismien ja haplotyyppien yhteys Alzheimer-riskiin on raportoitu. Aineistossamme APOE e2/3/4 ei assosioitunut PT riskiin, eivät myöskään -219G/T, +113G/C polymorfismit tai APOE haplotyypit.
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