Increased risk of essential tremor in first-degree relatives of patients with Parkinson's disease.

We conducted a historical cohort study of 981 first-degree relatives of 162 patients with Parkinson's disease (PD) and of 838 first-degree relatives of 147 controls representative of the population of Olmsted County, Minnesota. In addition, we studied 2,684 first-degree relatives of 411 patients with PD referred to the Mayo Clinic. Relatives were interviewed and screened for tremor either directly or through a proxy, and those who screened positive were examined or copies of their medical records were obtained to confirm the diagnosis of essential tremor (ET). We also obtained ET information from a medical records-linkage system (family study method). In the population-based sample, the risk of ET was significantly increased for relatives of patients with onset of PD相似文献   

Lack of familial aggregation of Parkinson disease and Alzheimer disease

OBJECTIVE: To investigate the risk of Alzheimer disease (AD) in first-degree relatives of patients with Parkinson disease (PD) compared with first-degree relatives of controls. DESIGN: Case-control study, family history method, and reconstructed cohort approach. METHODS: Probands with PD without dementia and control probands, matched by age strata, sex, and ethnicity, were examined in person and enrolled without knowledge of family history of PD and other neurological disorders. Disease status in first-degree relatives of probands with PD and control probands was ascertained through a structured family history interview administered to the proband and a second informant (self-report or another informant). Cox proportional hazards models with double-censoring techniques for missing information on age of onset of AD were used to analyze the risk of AD in first-degree relatives of patients with PD compared with first-degree relatives of controls. RESULTS: Four hundred eighty-seven probands with PD and 409 control probands provided family history information on 4819 first-degree relatives older than 30 years (2534 relatives of probands with PD and 2285 relatives of control probands). One hundred thirteen first-degree relatives (2.3%; 61 relatives [2.4%] of patients with PD and 52 relatives [2.3%] of controls) were diagnosed with AD. The risk of AD was not increased in relatives of patients with PD compared with relatives of controls (hazard ratio, 1.1; 95% confidence interval, 0.7-1.6; P =.65). Similarly, no significantly increased risk of AD was observed when comparing relatives of patients with early-onset (< or =50 years) and late-onset (>50 years) PD with relatives of controls. CONCLUSION: The lack of familial aggregation of PD and AD does not support the hypothesis of major shared genetic contributions to the etiology of the 2 most common neurodegenerative disorders.     

Familial aggregation of early- and late-onset Parkinson's disease

The role of heredity in early- versus late-onset Parkinson's disease (PD) is controversial. We estimated the degree of increased risk of PD in first-degree relatives of 221 PD probands with age of onset 50 years or younger and 266 PD probands with age of onset older than 50 years compared with the first-degree relatives of 409 control probands. Risk of PD was similar among first-degree relatives of early-onset PD probands (risk ratio [RR], 2.9; 95% confidence interval [CI], 1.6-5.0; p = 0.0002) and late-onset PD probands (RR, 2.7; 95% CI, 1.6-4.4; p = 0.0002) when each was compared with first-degree relatives of controls. However, siblings of early-onset PD probands were at markedly increased risk of PD compared with siblings of controls (RR, 7.9; 95% CI, 2.5-25.5; p = 0.0005), whereas parents of early-onset PD probands were not at significantly increased risk compared with parents of controls (RR, 1.7; 95% CI, 0.9-3.3; p = 0.2). In late-onset families, both siblings (RR, 3.6; 95% CI, 1.3-10.3; p = 0.02) and parents (RR, 2.5; 95% CI, 1.4-4.6; p = 0.003) were at increased risk compared with control relatives. This pattern is consistent with an autosomal recessive contribution to the inheritance of early but not late-onset PD. Genetic factors are important in both early- and late-onset PD, but specific genes and mode of inheritance may differ between the two groups.     

Familial aggregation of Parkinson's disease in a multiethnic community‐based case‐control study

To assess the familial aggregation of Parkinson's disease (PD), we compared the cumulative incidence of PD among first‐degree relatives of PD cases and controls. We identified newly diagnosed patients with PD (n = 573) during 1994 to 1995 within Kaiser Permanente Medical Care Program of Northern California and recruited 496 cases (87%) for the case‐control study. Of 720 eligible controls matched by birth year and sex to cases, 541 (75%) agreed to participate. Information on family history of PD and other neurodegenerative diseases was obtained by in‐person structured interview. We used the reconstructed cohort approach that provides a better estimate of the risk. The cumulative incidence of PD was significantly higher among relatives of PD patients compared with relatives of controls (2.0 vs. 0.7%; relative risk (RR) = 3.4, 95% confidence interval (CI) 1.9–5.9; P = 0.0001). The degree of familial aggregation was higher among first‐degree relatives of Hispanic PD cases compared with Hispanic controls (3.7% vs. 0.4%; RR = 8.5, 95% CI 1.0–68.9) than it was among non‐Hispanic Caucasian cases and controls (2.0% vs. 0.8%; RR = 2.7, 95% CI 1.5–5.1; P = 0.02). The familial aggregation of PD was stronger among the siblings of PD cases (RR = 5.4, 95% CI 1.8–16.0) than among parents (RR = 2.7, 95% CI 1.3–5.2). The incidence and familial aggregation of PD is highest among Hispanics, warranting further studies of genetic and environmental risk factors in the Hispanic population. © 2010 Movement Disorder Society     

Risk of tremor and impairment from tremor in relatives of patients with essential tremor: a community-based family study.

Essential tremor (ET) is a common condition that is present in as many as 23% of elderly individuals. Our objective was to determine the risk of ET and to study the impairment resulting from ET among relatives of ET cases compared to relatives of controls. ET cases and matched controls from the Washington Heights-Inwood community, New York, and their first- and second-degree relatives underwent a standardized tremor examination. The risk of having ET in relatives of cases vs relatives of controls was compared using Cox proportional hazards models. Five hundred ninety-one subjects were examined (59 ET cases, 72 controls, 234 case relatives, and 226 control relatives). ET was present in 25 (22.5%) of the 111 first-degree relatives of cases compared to 6 (5.6%) of 107 first-degree relatives of controls [relative risk (RR) = 4.67, 95% confidence interval (CI) = 1.90-11.49, p = 0.0008]. RRs were higher in relatives of cases with onset < or =50 years than in those with later onset (RR = 10.38 vs 4.82). Sixteen (64%) of twenty-five affected first-degree case relatives exhibited moderate tremor while performing tasks such as writing, drinking, or pouring. Relatives of ET patients are five times more likely to develop the disease than are members of the population and ten times more likely if the proband's tremor began at an early age. The majority of the affected relatives can expect to experience impairment resulting from tremor.     

Variability of familial risk of Alzheimer disease across the late life span

CONTEXT: The role of genetic factors in Alzheimer disease (AD) varies across the late life span, complicating efforts to quantify the risk of AD for relatives of probands with AD. OBJECTIVES: To visualize the changing levels of familial risk according to proband onset age and the age of the at-risk relative and to determine the familiality of age at onset in AD. DESIGN: A retrospective, informant-based family study. SETTING, PATIENTS, AND OTHER PARTICIPANTS: Siblings and parents of probands with AD (relatives = 4687; probands = 904), ascertained at geriatric clinic and nursing home settings, and of elderly probands without dementia (relatives = 7649; probands = 1525) who were spouses of probands, participants at senior centers, or nursing home residents without dementia. MAIN OUTCOME MEASURES: Informant-based assessments of AD in the relatives were used to generate 3-dimensional surfaces representing the patterns of risk of AD across the late life span depending on the specific onset age of the proband with AD (or assessment age of the elderly proband without dementia). We then constructed a 3-dimensional, age-specific, 10-year hazard rate ratio (HRR) surface representing the relative risk of AD in relatives of probands with AD with smoothly shifting levels of onset age compared with relatives of elderly probands without dementia. RESULTS: The HRR surface peaked (HRR, 13.0) for younger sexagenarian relatives related to probands with AD with onset age in their early 60s. The HRRs dropped sharply both as the proband age at onset and the age of the relative increased. For relatives aged in their late 80s, the HRR fell lower than 2.0 regardless of proband onset age and their lower-limit 95% confidence intervals were less than 1.0. CONCLUSIONS: The role of genetic risk factors decreases with increasing onset age of the proband with AD regardless of the age of the relatives themselves. The familiality of onset age is greatly reduced at later ages. The role of environmental risk factors in AD likely increases with onset age.     

Validity of family history data on essential tremor.

BACKGROUND: In family studies of essential tremor (ET), valid data on the presence of ET in relatives of probands with ET is important. The family history method uses information obtained by interviewing probands with ET to identify ET in their relatives. The validation of this method by direct examination of the relatives has not been performed. OBJECTIVE: To determine the validity of family history data on ET in families in which the proband has ET. METHODS: ET cases (probands) and their respective relatives were enrolled in a genetic study of ET in Washington Heights-Inwood, New York. Each underwent a tremor interview and videotaped examination. Two neurologists rated the severity of tremor and assigned diagnoses (ET versus normal). Probands were asked to identify their relatives who had ET. The validity of the probands' responses was tested against the neurologists' diagnoses. RESULTS: There were 206 subjects: 46 ET cases and 160 relatives. Twelve (7.5%) of 160 relatives were diagnosed with ET (four definite ET and eight probable ET). Probands with ET reported that two of these 12 had tremor (sensitivity of probands' report = 16.7%). Six of the 12 affected relatives (50.0%) reported their own tremor. The probands reported that one of 136 of their unaffected relatives had tremor (specificity of probands' report = 99.3%). CONCLUSIONS: For family studies of ET, information on reportedly unaffected relatives is of limited use given the low sensitivity of family history data. The neurologic examination remains the only valid means of ascertaining cases of ET among relatives.     

Delineating nonmotor symptoms in early Parkinson's disease and first‐degree relatives

Nonmotor symptoms (NMS) are an important prodromal feature of Parkinson's disease (PD). However, their frequency, treatment rates, and impact on health‐related quality of life (HRQoL) in the early motor phase is unclear. Rates of NMS in enriched at‐risk populations, such as first‐degree PD relatives, have not been delineated. We assessed NMS in an early cohort of PD, first‐degree PD relatives and control subjects to address these questions. In total, 769 population‐ascertained PD subjects within 3.5 years of diagnosis, 98 first‐degree PD relatives, and 287 control subjects were assessed at baseline across the following NMS domains: (1) neuropsychiatric; (2) gastrointestinal; (3) sleep; (4) sensory; (5) autonomic; and (6) sexual. NMS were much more common in PD, compared to control subjects. More than half of the PD cases had hyposmia, pain, fatigue, sleep disturbance, or urinary dysfunction. NMS were more frequent in those with the postural instability gait difficulty phenotype, compared to the tremor dominant (mean total number of NMS 7.8 vs. 6.2; P < 0.001). PD cases had worse HRQoL scores than controls (odds ratio: 4.1; P < 0.001), with depression, anxiety, and pain being stronger drivers than motor scores. NMS were rarely treated in routine clinical practice. First‐degree PD relatives did not significantly differ in NMS, compared to controls, in this baseline study. NMS are common in early PD and more common in those with postural instability gait difficulty phenotype or on treatment. Despite their major impact on quality of life, NMS are usually under‐recognized and untreated. © 2015 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.     

Familial patterns of risk in very late-onset Alzheimer disease

BACKGROUND: The incidence of Alzheimer disease (AD) peaks after 85 years of age. Although genetic factors are implicated in AD with substantially earlier onset, the familial characteristics of high-incidence very late-onset AD (VLOAD, defined here as AD with onset age >/=85 years) remain unknown. METHODS: We collected information pertaining to the cognitive status and demographics of 809 parents and siblings of 144 VLOAD probands, 4235 parents and siblings of 793 earlier-onset AD probands, and 7646 parents and siblings of 1493 nondemented elderly probands. Cumulative risks and 5-year interval-specific hazard rate ratios were calculated for AD in relatives of the 2 AD proband groups and relatives of the nondemented elderly group. RESULTS: The cumulative risk for AD in the relatives of VLOAD probands was significantly different than that in the relatives of earlier-onset AD probands (P<.001), but not in the relatives of nondemented elderly probands. Also, the relatives of earlier-onset AD probands had hazard rate ratios ranging from 19.7 in those aged 50 to 54 years to 1.2 in those aged 90 to 94 years. Rates successively dropped as age intervals increased. CONCLUSIONS: At least through the middle of the ninth decade of life, relatives of VLOAD probands have a lower risk for AD than those of earlier-onset AD probands. In addition, the relatively increased risk of relatives of earlier-onset AD probands is highest at younger ages and diminishes with increasing age. In counseling family members of patients with AD concerned about their own risk, the onset age of the patient and the age of the concerned relative should be considered. Very late-onset AD may be a good target for investigating environmental factors associated with AD.     

Assessment of genetic risk for Alzheimer's disease among first-degree relatives

Life table methods were used to determine the relative risk of Alzheimer's disease (AD) in relatives of index cases with AD. Risk of AD was assessed in 967 first-degree relatives of 128 probands with clinically diagnosed AD and 572 first-degree relatives of a control group consisting of 84 subjects with Parkinson's disease (PD). Using a method that weights likelihood of correct diagnosis of AD, cumulative risk among AD relatives by age 93 was 24%, whereas relatives of the PD probands had a weighted risk of 16% by age 90. Overall, the total lifetime risk of developing dementia was similar among first-degree relatives of patients with AD and those of patients with PD. The age-specific risks were much different, however; from the age of 65 years to the age of 80 years, relatives of patients with AD had a twofold to fourfold increased risk of dementia. Equal risks were found for parents and siblings and for male and female relatives after adjustment for sex-specific patterns of survivorship. Relatives of probands with early-onset (less than or equal to 67 years) and late-onset (greater than 67 years) AD had equivalent risks of developing illness. Because onset age was found to cluster in families, the apparent increase in cumulative incidence for dementia in relatives of early-onset cases was likely due to relatives of the late-onset cases dying before developing illness.(ABSTRACT TRUNCATED AT 250 WORDS)     

Nonlinear dynamic analysis of oscillatory repetitive movements in Parkinson's disease and essential tremor

Uncertainty exists on whether Parkinson's disease (PD) and essential tremor (ET) patients have similar degree of impairment during motor tasks. We investigated this problem by analyzing nonlinear dynamics of repetitive movements in 21 control subjects, 33 mild‐moderate PD patients, and 18 ET patients. Accelerometer signals were recorded during finger tapping and unbounded forearm movements between two points, and processed with moving average filtering to generate a new signal consisting of the temporal distance between consecutive cycles. We calculated: mean interpeak interval (slowness), interpeak interval variability (irregularity), and beat decay (BD) of the auto mutual information (AMI) value, which estimates signal predictability by measuring the loss of signal information over a timescale. Both PD and ET had longer interpeak interval (except for finger tapping), higher interpeak interval variability, and higher BD‐AMI values than controls (P ≤ 0.007, all comparisons). ET patients had higher BD‐AMI values than PD (P = 0.003). BD‐AMI was the parameter that discriminated better between subjects (diagnosis accuracies about 80%). No differences existed between PD patients with and without tremor or between PD or ET patients with different disease stages, for any parameter. Evaluation of nonlinear dynamics of oscillatory repetitive movements is a feasible and promising tool for studying movement physiology. Movement performance is more predictable in PD and ET than in controls, even in early disease stages. Slowness and irregularity of movement in PD and ET cannot be fully explained by tremor. Some common pathogenic mechanisms leading to bradykinesia may contribute to this impairment. © 2010 Movement Disorder Society     

Subclinical tremor in normal controls with versus without a family history of essential tremor: data from the United States and Turkey

Background and purpose: Mild action tremor is very common in the population. One fundamental question is whether this tremor is related to the neurological disease essential tremor (ET), which occurs in a much smaller segment of the population? ET is often genetic, and variable phenotypic expression is well‐documented in the literature. We determined whether normal controls who report a family history of ET have greater action tremor than normal controls who do not report such a history. Methods: Controls, enrolled in two epidemiological studies (New York and Turkey), were examined in detail and action tremor was rated using a valid and reliable clinical rating scale, resulting in a total tremor score (range 0–36). Results: In New York, the total tremor score was higher in 44/406 (10.8%) controls who reported a family history of ET than in 362/406 controls with no such history (4.25 ± 2.51 vs. 3.78 ± 2.93, P = 0.02). Controls who reported a first‐degree relative with ET had the highest total tremor scores. In Turkey, the total tremor score was higher in 7/89 (7.9%) controls with a family history than in 82/89 controls with no family history (3.43 ± 4.54 vs. 1.13 ± 2.54, P = 0.048). All affected relatives in Turkey were first‐degree. Conclusions: These data suggest that some of the normal tremor exhibited by people in the population is likely to be subclinical, partially expressed ET and that the sphere of ET is wider than is apparent from a consideration of clinically diagnosed cases.     

Has familial aggregation in Alzheimer's disease been overestimated?

Studies of the familial aggregation of Alzheimer's disease have primarily used samples ascertained from tertiary care clinics which may not be representative of many AD patients, for example those residing at geriatric nursing homes. Survival analysis was used to investigate whether estimates of familial aggregation of AD based on a clinic-based AD proband (C-AD) sample (probands: N=544; first degree relatives; N=4267) differ from one ascertained at a nursing home (NH-AD; probands: N=225; first degree relatives; N=1772). The cumulative survival from AD was significantly worse in relatives of the C-AD probands and the overall relative risk (RR) of AD in this group was greater than twice that of relatives of the NH-AD probands. However, age at onset in C-AD probands was significantly earlier than in the NH-AD group and in both groups this factor was negatively associated with familial aggregation. When, for this reason, the proband samples were matched one-to-one by age at onset, dropping those probands with no match, the two curves were close to identical and the RR for the C-AD group of relatives was 1.0 The results suggest that estimates of familial risk of AD based on C-AD samples are not applicable and overestimate the extent of increased risk for relatives of more prevalent, later onset AD probands. However, the overestimate can be explained by the typically earlier age at onset in C-AD samples as opposed to a sampling bias related to the proband's family history status per se. The relationship between onset age and familial aggregation suggests that no single estimate of the age-dependent risk (survival curve) is uniformly appropriate for relatives of AD probands.     

Color vision in Parkinson’s disease and essential tremor

Background and purpose: Decreased visual function is one of the non‐motor dysfunctions of Parkinson’s disease (PD). Recent evidences suggest that essential tremor (ET) is not ‘pure’ motor disorder and there is growing evidence that this disease is a multiple‐system disorder. In some cases, it is difficult to differentiate ET from PD. In addition, there is considerable controversy regarding the relationship between PD and ET. The objective of this study was to compare color discrimination dysfunction amongst patients with PD and ET and to investigate the clinical relevance. Methods: Case–control comparisons of 54 patients with PD, 36 patients with ET, and 34 age‐matched controls were performed. All cases underwent Farnsworth–Munsell 100 Hue test (FMT) and clinical assessments on medication. In addition, the association between color vision abnormalities and motor handicaps was investigated. Results: There were significant differences in the total error scores (TES) of the FMT amongst the three groups; patients with the PD had higher TES than the patients with ET and the controls after adjustments for age. In addition, the motor symptom severity in PD correlated with the FMT abnormalities, especially with regard to the axial symptoms. Conclusion: The results of this study suggest that color vision abnormalities may be one of the non‐motor clinical characteristics of PD‐related dysfunction in contrast to ET. In addition, the severity of axial motor symptoms was closely related to visual dysfunction. Confirmation of these findings as well as the mechanisms underlying these results requires further study.     

Familial occurrence of Parkinson's disease in a community-based case-control study

Purpose: To study the occurrence of Parkinson's disease (PD) in the relatives of parkinsonian patients (n=119), and of their matched controls (n=238).

Scope: More patients reported a positive family history of PD in their first degree relatives, compared to their controls (OR 2.7, 95% CI 1.3–5.9), and the incidence of PD among those relatives was also significantly higher (OR 1.4, 95% CI 1.1–1.8).

Conclusions: Familial occurrence of PD is not necessarily a sign of genetic mechanisms in the etiology of PD. Shared environment with common risk factors might be even more important.     

LINGO1 gene analysis in Parkinson's disease phenotypes

Background: Parkinson's disease (PD) and essential tremor (ET) may share some etiopathogenic factors. A genome‐wide association study has shown that LINGO1 gene variants are associated with increased risk of ET. We hypothesized that LINGO1 variants could increase susceptibility to PD. Methods: A large series of PD subjects and healthy controls were genotyped for rs9652490 and rs11856808 LINGO1 single nucleotide polymorphisms (SNPs). Results: We found an increased frequency of the rs11856808^T/T genotype in PD compared with controls (odds ratio = 1.46; corrected P value = 0.02). A recessive genetic model was the best fit for rs11856808 influence on PD (recessive gene action test: corrected P value = 0.01). Stratification analysis showed that rs11856808^T/T genotype frequency was higher in the tremor‐dominant PD and the classical PD (C‐PD) subgroups (recessive gene action test for the C‐PD subgroup: corrected P value = 0.004). Discussion: Our results indicate that LINGO1 variants could increase risk of PD, specifically those presenting the non‐rigid‐akinetic phenotypes, which suggests that LINGO1 may have a role in the etiology of tremor in PD at least in the Spanish population. © 2010 Movement Disorder Society     

Risk of cognitive impairment or dementia in relatives of patients with Parkinson disease

BACKGROUND: The evidence for increased risk of dementia in relatives of patients with Parkinson disease (PD) remains conflicting. OBJECTIVE: To study the risk of cognitive impairment or dementia in first-degree relatives of patients with PD. Design, Setting, and PARTICIPANTS: We conducted a historical cohort study of 1019 first-degree relatives of 162 patients with PD and of 858 relatives of 147 matched controls representative of the population of Olmsted County, Minnesota. In addition, we studied 2716 first-degree relatives of 411 patients with PD referred to Mayo Clinic. MAIN OUTCOME MEASURES: We administered via telephone a cognitive test directly to relatives or a dementia questionnaire to proxies. For relatives reported by proxies to have dementia, we obtained copies of their medical records to confirm the diagnosis. We also obtained dementia information from a medical records-linkage system. RESULTS: In the overall population-based sample, the risk of cognitive impairment or dementia was increased in relatives of patients with PD compared with relatives of controls (hazard ratio, 1.37; 95% confidence interval, 1.03-1.81; P = .03) and was particularly increased in relatives of patients with onset of PD at age 66 years or younger (youngest tertile; hazard ratio, 1.73; 95% confidence interval, 1.21-2.46; P = .003). The findings were consistent in several sensitivity analyses. In the referral-based sample, the risk of cognitive impairment or dementia in relatives increased with younger age at onset of PD but did not vary by other clinical characteristics. CONCLUSION: Cognitive impairment or dementia may share familial susceptibility factors with PD (genetic or nongenetic).     

Imaging essential tremor

To investigate over time changes in striatal dopamine transporter (DAT), we performed two sequential N‐ω‐fluoropropyl‐2β‐carbomethoxy‐3β‐(4‐iodophenyl) tropane single photon computed tomography (SPECT) scans in 20 subjects with essential tremor (ET), in 13 with Parkinson disease (PD) and in 23 healthy controls (HC, one scan only). We also performed an [^99mTc]ethyl cysteinate dimer bicisate SPECT exam for regional brain network analysis in 9 ET, in a second group of 18 PD (9 with tremor, tPD and 9 akinetic‐rigid dominant, arPD) and in 8 HC. PD subjects had a reduced DAT binding in comparison to ET and HC with an annual decline rate of 7.3% in the contralateral putamen. There were no mean uptake differences between ET and HC at baseline and no uptake loss over time in ET. A discriminant analysis grouped 30% (first scan) and 5% (second scan) of ET as PD and a partition analysis showed overlap between ET and PD for caudate nucleus uptake. Spatial covariance analysis revealed that the expression of the PD‐related regional pattern separated both tPD and arPD from ET and HC. In conclusion, PD and ET do not share a common pattern of dopaminergic loss over time. However, mild impairment of dopamine transporter in the caudate nucleus may contribute to tremor onset in ET. © 2010 Movement Disorder Society     

In families with inherited thrombophilia the risk of venous thromboembolism is dependent on the clinical phenotype of the proband

The utility of laboratory investigation of relatives of individuals with inherited thrombophilia is uncertain. To assess the risk of venous thromboembolism (VTE) among the carriers, we investigated a family cohort of 1,720 relatives of probands with thrombophilia who were evaluated because of VTE (n=1,088), premature arterial thrombosis (n=113), obstetric complication (n=257), or universal screening before pregnancy or hormonal contraception or therapy (n=262); 968 relatives were carriers of thrombophilia. A first deep venous thrombosis (DVT) occurred in 44 carriers and 10 non-carriers during 37,688 and 29,548 observation-years from birth, respectively. The risk of DVT among the carriers compared with non-carriers was estimated as a hazard ratio (HR). If the proband had VTE and factor V Leiden (FVL) and/or prothrombin (PT)20210A, the HR for DVT was 2.77 (95%CI 1.21-4.82) in the carriers overall, and 5.54 (95%CI 3.20-187.00) in those homozygous or double heterozygous for FVL and PT20210A. If the proband had VTE and a deficiency of antithrombin (AT), protein C or S, the HR for DVT was 5.14 (95%CI 0.88-10.03) in the carriers overall, and 12.86 (95%CI 2.46-59.90) in those with AT deficiency. No increase in risk was found among the carriers who were relatives of the probands who were evaluated for reasons other than VTE. In conclusion, familial investigation for inherited thrombophilia seems justified for probands with previous VTE, but appears of doubtful utility for the relatives of probands without VTE. This should be taken with caution regarding families with deficiency of natural anticoagulants, given the low number of cases analysed.     

The role of environmental factors in Parkinson's disease may depend on disease onset age

BACKGROUND AND PURPOSE: Various factors are suspected to participate in PD onset and include environment-related factors and workplace exposure to pesticides, metals and hydrocarbons. Nevertheless, results of epidemiological research are inconsistent. Some authors emphasize hydrocarbons exposure to younger patients. Our aim was to compare PD risk factors to onset age. MATERIAL AND METHODS: Of 174 patients with idiopathic PD, without dementia, two subgroups were isolated: 65 patients with early onset PD (EOPD) below 50 (n=65, age 52.8+/-7.6 years, onset 42.8+/-5.3 years) and 109 patients with late onset (LOPD) above 50 (n=109, age 67.8+/-7.0, onset 60.8+/-6.7 years). Various environmental factors reported in literature were analyzed. RESULTS: The univariate analysis showed that factors significantly predisposing to EOPD are vocational education (OR 3.24, 95%CI 1.50-7.00, p<0.003), smoking (OR 1.94, 95%CI 1.02-3.69, p<0.05), well water consumption at 20-40 (OR 2.77, 95%CI 1.31-5.86, p<0.008), and after 40 (OR 4.84, 95%CI 1.95-11.99, p<0.0007), side-effects following exposure to paints (OR 2.26, 95%CI 1.10-4.66, p<0.03) and exposure to solvents (OR 1.98, 95%CI 0.96-4.07, p<0.07) on borderline significance. Drinking well water both between 20-40 and after 40 involved a substantial increase in EOPD (OR 6.57, 95%CI 2.43-17.75, p<0.0002). Education only at a primary level proved to be protective against EOPD (OR 0.20, 95%CI 0.07-0.55, p<0.002). The multivariate logistic regression model demonstrated that independent EOPD risk factors are smoking (OR 2.20, 95%CI 1.07-4.53, p<0.04) and well water consumption both between 20-40 and after 40 (OR 8.29, 95%CI 2.73-25.23, p<0.0002), whilst the independent protective factor is education only at a primary level (OR 0.17, 95%CI 0.05-0.53, p<0.003). CONCLUSIONS: Our research demonstrated that a number of independent environmental factors significantly affect the risk of PD onset at younger ages. Presumably, some of the observed differences in the results of research of various authors into PD risk factors may be caused by ignoring onset age within the researched patients.