Hexosaminidase A deficiency is an uncommon cause of a syndrome mimicking amyotrophic lateral sclerosis

Patients with adult hexosaminidase A (Hex A) deficiency may have clinical manifestations similar to amyotrophic lateral sclerosis (ALS). Mutations in the hexosaminidase A (HEXA) gene are common in the Jewish Ashkenazi population in Israel. Serum samples of 115 Israeli patients with sporadic ALS were screened for enzymatic activity to detect "enzyme-based carriers." Fifteen samples with low (< 50%) enzymatic activity were subjected to mutation analysis, which included the two common mutations in the HEXA gene among Ashkenazi Jews (+1278TATC and IVS12+1G-->C). Three "enzymatic carrier" patients of Moroccan origin were checked for two additional mutations (DeltaF304/305 and Arg170-->Gln), specific to this ethnic group. Two "enzymatic carrier" patients of Iraqi origin were analyzed for the mutation Gly250-->Val, specific to this population. The mutation Gly 269-->Ser was screened in carriers of Ashkenazi origin only (n = 10). The only abnormalities found were heterozygous +1278TATC mutations in two Ashkenazi patients. Their clinical presentation was not different from that usually encountered in ALS. The frequency of mutations in the HEXA gene among Israeli ALS patients was not higher than in the healthy Israeli population. Therefore, Hex A deficiency seems to be a very unlikely cause of an ALS-mimic syndrome.     

Variants in the catechol-o-methyltransferase (COMT) gene are associated with schizophrenia in Irish high-density families

The enzyme catechol-o-methyltransferase (COMT) transfers a methyl group from adenosylmethionine to catecholamines including the neurotransmitters dopamine, epinephrine and norepinephrine. This methylation results in the degradation of catecholamines. The involvement of the COMT gene in the metabolic pathway of these neurotransmitters has made it an attractive candidate gene for many psychiatric disorders. In this article, we reported our study of association of COMT with schizophrenia in Irish families with a high density of schizophrenia. Three single nucleotide polymorphisms (SNPs) were genotyped for the 274 such families and within-family transmission disequilibrium tests were performed. SNP rs4680, which is the functional Val/Met polymorphism, showed modest association with the disease by the TRANSMIT, FBAT and PDT programs, while the other two SNPs were negative. These SNPs showed lower level of LDs with each other in the Irish subjects than in Ashkenazi Jews. Haplotype analysis indicated that a haplotype, haplotype A-G-A for SNPs rs737865-rs4680-rs165599, was preferentially transmitted to the affected subjects. This was different from the reported G-G-G haplotype found in Ashkenazi Jews, but both haplotypes shared the Val allele. We concluded that COMT gene is associated with schizophrenia and carries a small but significant risk to the susceptibility in the Irish subjects.     

The association between genetic variants in SORL1 and Alzheimer disease in an urban, multiethnic, community-based cohort

OBJECTIVE: To investigate the association between Alzheimer disease (AD) and variant alleles in SORL1 using a series of single nucleotide polymorphisms (SNPs) in an urban, multiethnic, community-based population. DESIGN: We used a nested case-control analysis in a population-based, prospective study of aging and dementia in Medicare recipients, 65 years and older. SETTING: Northern Manhattan, NY. PARTICIPANTS: There were 296 patients with probable AD and 428 healthy, elderly controls. The participants were African American (34%), Caribbean Hispanic (51%), or non-Hispanic white (15%). MAIN OUTCOME MEASURES: We genotyped all 29 SNPs in SORL1 that were examined in the earlier report. We assessed allelic association with AD using standard case-control methods, which included apolipoprotein E genotype as a covariate. RESULTS: Several individual SNPs and SNP haplotypes were significantly associated with AD in this prospectively collected community-based cohort, confirming the previously reported positive association of SORL1 with AD. Single nucleotide polymorphism 12, near the 5' region, was associated with AD in African American and Hispanic individuals. Two SNPs in the 3' region were also associated with AD in African American (SNP 26) and non-Hispanic white (SNP 20) individuals. A single haplotype in the 3' region was associated with AD in Hispanic individuals. However, several different haplotypes were associated with AD in African American and white individuals, including the TTC haplotypes at SNPs 23 through 25 (P = .035), which was significantly associated with AD in the North European white individuals in our previous report. CONCLUSIONS: This study confirms the association between genetic variants in SORL1 and AD. While the associations observed in these data sets overlap with those previously reported, the finding of novel SNP and haplotype associations suggests that there may be extensive allelic heterogeneity in SORL1. Broad regions of the SORL1 gene will therefore need to be scrutinized for functional pathogenic variants.     

Aseptic meningitis: Frequency among Israeli ethnic groups

The relative frequency of aseptic meningoencephalitis (AME) was compared in populations of diverse origin, A countrywide search of Israel during 1969-1970 disclosed 1350 cases who fit strict diagnostic criteria. The average annual incidence was 21.6 per 100000 population. The total incidence was similar in Afro-Asian, Euro-American and Israeli Jewish groups but among Israeli Arabs, the incidence was apparently lower. Age-specific incidence showed a peak in infants under one year of age among Arabs and Afro-Asian Jews whereas Euro-Americans and Israeli Jews had a peak incidence at 5-9 years. Larger family size among Arabs and Afro-Asian Jews might account for the higher incidence in infants. Age-specific incidence may be a better index than total incidence of important differences in AME among various ethnic groups.     

The frequency of multiple sclerosis in jewish and arab populations in greater jerusalem

A comparison of the incidence rate (IR) and the prevalence rate (PR) of multiple sclerosis (MS) in subgroups of the same ethnic origin, but born and living in different geographical areas, may delineate the relationship between environmental and genetic risk factors for MS. Previous epidemiological studies of MS in Israel did not include the Arab population and used diagnostic criteria that did not include MRI findings. Therefore, we studied the age-adjusted IR and PR of MS in a more recent sample in different population groups, including Arabs, of Greater Jerusalem. We found that the PR of MS in Israeli Jews is higher than previously described. Furthermore, the PR was significantly lower among immigrant Jews from Asia/Africa (A/A) than among native-born Jews of Asian/African origin (I-A/A). Since these groups have similar genetic susceptibilities to MS, the higher PR in the latter is probably due to environmental factors. Our study does not support the effect of latitude on the risk of developing MS since no difference in the PR was found between immigrant Jews from Europe/America (E/A) and native-born Jews of European/American origin (I-E/A). Among Arabs, the PR was similar to that among A/A. Therefore, we hypothesized similarity in environmental etiologic factors for MS between the countries of origin of A/A immigrants and of Arabs communities in Greater Jerusalem. The IR of I-E/A was higher than that of I-A/A and Arabs, although this difference did not reach statistical significance.     

Clinical characteristics of Parkinson’s disease among Jewish Ethnic groups in Israel

Yemenite Jews in Israel are a distinctive ethnic division of the Jewish diaspora. Clinical findings, disease course and genetic tests for the LRRK2 6055G > A (G2019S) mutation were compared between Ashkenazi and Yemenite Israeli patients with Parkinson's disease (PD). Age of onset was significantly younger in the Yemenites (P < 0.001). There were no differences in the distribution of initial symptoms, environmental risk factors or rate of motor/non-motor phenomena. The Yemenite group had a more severe disease (P < 0.001), and a more rapid disease course (P = 0.006). The frequency of Lrrk2 substitution was 12.7% in the Ashkenazi group and was not observed in the Yemenites. These results show that there are differences between Israeli Jewish ethnic groups in the severity and progression of PD, but not in clinical symptoms. The high frequency of Lrrk2 G2019S in the Ashkenazi and its absence in the Yemenite Jews suggests a specific ancestral pattern of inheritance in Ashkenazi Jews.     

Is the G2019S LRRK2 mutation common in all southern European populations?

Mutations in the leucine-rich repeat kinase 2 (LRRK2) gene, especially the G2019S mutation, have been identified as a common cause of Parkinson's disease in southern European and other Mediterranean populations (Iberians, Ashkenazi Jews and North African Arabs). Owing to the geographic and historic vicinity of Greece with areas of high prevalence of LRRK2 mutations we studied the frequency of the G2019S mutation in a well characterized cohort of familial and sporadic Parkinson's disease patients of Greek origin from mainland Greece. The prevalence of the LRRK2 R1441C mutation and the G2385R Asian polymorphism was also determined. We identified no patients with any of the studied mutations/polymorphisms. Very low prevalence of the LRRK2 G2019S mutation has been reported in other southern European populations. LRRK2 mutations appear to be limited in certain populations and differing ancestry and founder effects may explain the reported variability. Accurate estimations of the frequency and penetrance of different LRRK2 mutations are essential for correct and cost-efficient use of genetic testing and proper genetic counseling of patients with Parkinson's disease.     

Analysis of common genetic variants identifies RELN as a risk gene for schizophrenia in Chinese population

Abstract

Objectives. Several lines of evidence have shown that both RELN mRNA and protein are possibly down-regulated in the brain of schizophrenia patients. Recent association studies in European populations suggested RELN as a risk gene for schizophrenia. In this study, we test if RELN contributes to the risk of schizophrenia in Chinese population. Methods. We conducted case-control association analysis of 19 representative single nucleotide polymorphisms (SNPs) spanning the entire region of RELN in two independent Han Chinese samples from southwestern China (the Kunming sample and the Yuxi sample). Results. We identified six SNPs significantly associated with schizophrenia in the Kunming sample and four of them remained significant in the combined samples (the P values range from 0.006 to 4.0 × 10^?5). Haplotype analysis also suggested significant associations for the haplotypes incorporating the six significant SNPs (global P < 1.0 × 10^?5). Additionally, we also observed several other haplotypes (defined by a different set of SNPs) significantly associated with schizophrenia in the Kunming sample. However, the reported association of rs7341475 in Ashkenazi Jews was not significant in Han Chinese. Conclusions: Our findings demonstrate that RELN is a susceptibility gene for schizophrenia in Chinese population, and it is likely a common risk gene for schizophrenia in major populations worldwide.     

Ashkenazi Parkinson’s disease patients with the LRRK2 G2019S mutation share a common founder dating from the second to fifth centuries

The LRRK2 G2019S mutation is a major genetic determinant of Parkinson’s disease (PD) across the world that occurs at an elevated frequency in Ashkenazi Jews. We determined the LRRK2 haplotypes in 77 G2019S carriers, mostly Ashkenazi Jews, and in 50 noncarrier Ashkenazi PD patients, using 16 genetic markers. A single haplotype was detected in all mutation carriers, indicating that these individuals share a common founder. Using a maximum-likelihood method, we estimate that Ashkenazi Jews with G2019S share a common ancestor who lived ～1,830 (95% CI 1,560–2,160) years ago, around the second century, after the second Jewish Diaspora.     

Molecular and clinical heterogeneity of adult GM2 gangliosidosis.

Adult GM2 gangliosidosis is a rare autosomal recessive disease with widely varying neurological and psychiatric manifestations. It is caused by marked deficiency, but not total absence, of beta-hexosaminidase (Hex) A, due to a single base change in the alpha-subunit gene of Hex, resulting in a substitution of Ser for Gly at position 269 in the alpha-subunit of the enzyme. The same mutation was identified in all investigated patients, most of whom are Ashkenazi Jews. Among previously studied non-Jewish patients of unrelated families this mutation appears either homozygously or in compound heterozygosity with an unidentified alpha-subunit mutation, whereas all Ashkenazi patients are compound heterozygotes. In all but one of them the other mutation is one of the Ashkenazi infantile Tay-Sachs alleles, while in one 76-year-old woman with very mild neurological symptoms, it is an unidentified alpha-subunit mutation. At present, the little correlation that seems to exist between these different genotypes and the severity of the disease poses a serious dilemma for genetic counselors.     

High frequency and reduced penetrance of LRRK2 G2019S mutation among Parkinson's disease patients in Cantabria (Spain)

The frequency and penetrance of the LRRK2 G2019S mutation varies considerably in different Parkinson disease (PD) populations. This information is essential both for clinical purposes and genetic counseling. The objective of this study was to estimate the prevalence and penetrance of the G2019S mutation of the LRRK2 gene in a small region in northern Spain (Cantabria). The G2019S mutation was tested in 367 consecutive patients with PD attended as outpatients in a tertiary Hospital in Northern Spain, and 126 at-risk family members of probands were also investigated for G2019S mutation and disease status. The gene penetrance was estimated in terms of cumulative age-specific incidence of PD by the Kaplan-Meier method. Thirty-two PD patients (8.7%) carried the G2019S mutation. Penetrance estimation of the G2019S mutation was 2% at 50 years, 12% at 60 years, 26% at 70 years, and 47% at 80 years. The frequency of the G2019S mutation of the LRRK2 gene in PD patients from Cantabria is among the highest reported so far after North African Arabs and Ashkenazi Jews. At the age of 80 years only one-half of G2019S mutation carriers manifest motor symptoms of PD.     

Mutations in the glucocerebrosidase gene and Parkinson disease: phenotype-genotype correlation

Mutations in the glucocerebrosidase (GBA) gene have been recently identified as contributory to Parkinson disease (PD) in Ashkenazi Jews. In the present study, the clinical characteristics of Ashkenazi patients with PD with GBA mutations (n = 40) were compared to those of Ashkenazi patients with PD without any known GBA mutation (n = 108). The overall clinical manifestations and age at disease onset did not differ in patients with GBA mutations compared to patients without mutations.     

Analysis of the LRRK2 Gly2385Arg variant in Alzheimer's disease in Taiwan

ObjectiveTo analyze the Gly2385Arg (G2385R) mutation in Taiwanese Alzheimer's disease (AD) patients.BackgroundThe leucine-rich repeat kinase 2 (LRRK2) gene is well known to predispose subjects to Parkinson's disease (PD). The Gly2385Arg (G2385R) variant of LRRK2 is believed to be “East Asian”-specific, particularly in the Han Chinese population; however, whether the LRRK2 G2385R is associated with a risk of AD in pure Han-Chinese patients has not often been studied.MethodsA total of 209 AD patients (87 men, 122 women) and 180 age- and gender-matched controls were recruited and the demographic data of the AD patients were analyzed. Genotyping of the Gly2385Arg variant was studied using matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry.ResultsSubjects with the Gly2385Arg variant were all heterozygous carriers. The frequency of Gly2385Arg carriers did not differ significantly between the AD patients and controls (4.78% versus 4.44%, odds ratio = 1.04, 95% CI = 0.62–1.77, P = 0.87). In the AD patient group, the age of symptom onset, the length of education, or the MMSE score showed no significant differences between wild-type carriers and heterozygous variant carriers (P = 0.51, 0.43, and 0.09).ConclusionThe Gly2385Arg variant of LRRK2 may not be a major risk factor for AD in pure Han Chinese patient. Among the AD patients, Gly2385Arg carriers were not clinically different from wild-type carriers.     

Daily stresses and uplifts during times of political tension: Jews and Arabs in Israel

This study examined similarities and differences between Jews and Arabs in Israel in terms of their daily stressful and uplifting experiences and assessed the relation between these experiences and family and life satisfaction. Data were collected from representative samples of 697 Jews and 303 Arabs by using a computerized-assisted telephone interviewing system. Contrary to expectation, Jews reported more sources of hassles than did Arabs, whereas Arabs reported more uplifts. A structural equation modeling multigroup analysis indicated a similar factor suucture for hassles and uplifts in both groups. Family satisfaction was positively related to uplifts but not to hassles. For Arabs, uplifts had a positive effect only on family satisfaction, whereas for Jews they had a positive effect on both family and general life satisfaction.     

Epidemiology of suicide in Israel: a nationwide population study

BACKGROUND: In Israel, some population characteristics and lifestyle patterns make epidemiological research on suicide of particular interest. The Israeli population is characterized by ethnic diversity, with a multi-religious, multi-national mosaic of Jews and Arabs. These subgroups also vary in their suicidal behavior. The aims of the present study were to examine the trends in suicide incidence rates in Israel from 1984 to 1994, to identify sub-populations at high risk for suicide and to identify suicide methods associated with increased risk. METHODS: Suicide rate trends in Israel over the period from 1984 to 1994 were examined for four subgroups: Jewish men and women, and Arab men and women. Cases of undetermined external cause (UEC) of death were also considered. Mortality data were obtained from the computerized data files of the Israeli Central Bureau of Statistics, which includes cause of death and sociodemographic variables. Suicide was classified according to the ICD-9 codes. RESULTS: Suicide rates were higher for Jews than for Arabs, and higher for men than for women. The rates among both population and sex groups increased directly with age. A significant increase over the years studied was found for Jewish men, particularly in the 18- to 21-year-old age group. An increase in the use of firearms was noted, mainly in the groups in which total suicide rates increased. CONCLUSIONS: The findings of this study highlight the need for further studies to identify both sub-populations at high risk for suicide, and societal trends such as lifestyles, immigration, military service, and media exposure to violence, as first steps toward planning of intervention programs to reduce suicide rates.     

Association of apolipoprotein E genotype and Alzheimer disease in African Americans

BACKGROUND: Alzheimer disease (AD) is the most frequent cause of dementia. Even though the incidence of AD in the African American population is similar to or higher than that in persons of European descent, AD in African Americans is understudied. Identification of genetic risk factors in African Americans is essential for understanding the etiology of AD. OBJECTIVE: To determine the effect of apolipoprotein E (APOE) genotype on the risk of AD in elderly African Americans. DESIGN: Population-based longitudinal study of AD. SETTING: Indianapolis, Ind. PARTICIPANTS: African Americans 65 years and older. MAIN OUTCOME MEASURES: APOE genotype and diagnosis of AD. RESULTS: The APOE genotype was determined in 1822 samples. Of these, 690 were clinically evaluated: 318 were normal, and 162 had a diagnosis of AD. The presence of APOE epsilon4 was significantly associated with increased risk of AD (epsilon3/epsilon4: OR, 2.32; 95% confidence interval [CI], 1.41-3.82; and epsilon4/epsilon4: OR, 7.19; 95% CI, 3.00-17.29, compared with the epsilon3/epsilon3 genotype). There was also a significant protective effect with APOE epsilon2 (epsilon2/epsilon2 and epsilon2/epsilon3: OR, 0.42; 95% CI, 0.20-0.89). CONCLUSIONS: These findings are in marked contrast to the lack of association between APOE and AD in the Ibadan, Nigeria, sample of this project. These results suggest that other genetic factors and different environmental influences may play a role in the risk for AD in individuals of African ancestry.     

LRRK2 is not a significant cause of Parkinson's disease in French-Canadians

BACKGROUND: An old founder mutation (G2019S) was found with high frequency in the North African Arabs (30%) and Ashkenazi Jews (18% ). Objective: Demonstrate if mutations in the LRRK2 gene are a significant cause of Parkinson's disease (PD) in the French-Canadian founder population. METHODS: Cases were recruited through a designated movement disorder clinic in Quebec City. Every index case had to meet the Ward and Gibb criteria for PD. Controls consisted of a non-disease group of similar age and ethnicity as the cases. Exons 31 and 41 of LRRK2 were amplified by PCR with intronic primers in all 125 PD cases and directly sequenced on an ABI 3700 sequencer. Six single nucleotide polymorphism were typed in 125 PD cases and 95 normal controls. Associations between unrelated cases and matched controls were analyzed. Single marker analysis and haplotype association tests were performed. RESULTS: Sequencing analysis did not reveal any reported or novel mutations in exons 31 and 41 of LRRK2. The G2019S mutation as well as mutations affecting amino acid 1441 were absent in the 125 patients. The case-control association study performed to detect the presence of a common variant in LRRK2 did not provide any positive signal. Single-marker and haplotype analyses systematically gave non-significant P values. CONCLUSIONS: We performed a case-control association study in 125 French-Canadian (FC) patients with PD and 95 FC controls and found that common variants in LRRK2 are unlikely to be a significant cause of late-onset PD in this founder population.     

Differences between African Americans and whites in their perceptions of Alzheimer disease

To design optimal health services and education programs for Alzheimer disease (AD), it is important to understand cultural differences in perceptions of the disorder. In this study, we investigated differences between African Americans and whites in their beliefs, knowledge, and information sources regarding AD. We distributed a written questionnaire through lay and professional organizations and meetings in the southeastern United States, yielding a sample of 452 adults (61% white, 39% African American; 78% female; mean age 47 years; 33% with family history of AD). The questionnaire assessed the following: (1) illness beliefs, (2) factual knowledge, (3) sources of information, and (4) perceived subjective threat of AD. African Americans and whites were generally similar in their beliefs about common symptoms, prominent risk factors, and the effectiveness of treatments for AD (although whites expressed greater certainty in these beliefs than African Americans). In comparison to whites, African Americans showed less awareness of facts about AD, reported fewer sources of information, and indicated less perceived threat of the disorder. These preliminary findings suggest important distinctions between African Americans and whites in their knowledge about, and conceptualization of, AD. Follow-up studies with more representative samples and more fully validated measures will be necessary to confirm these differences. Health psychologic research suggests that such differences in illness perceptions could shape response to disease burden, assessment and diagnosis, and available health care options.     

Mutation analysis in myophosphorylase deficiency (McArdle's disease)

Inherited deficiency of myophosphorylase leads to glycogen storage disease type V (McArdle's disease). We performed mutation analysis in 9 patients of eight unrelated families from Germany with typical cliniclal presentation of myophos-phorylase deficiency. Beside previously described mutations we identified four novel mutations in the myophorsphorylase gene. Four patients were homozygous for a nonsense mutation Arg49Stop that has been reported to be the most common mutation in white patients. Two affected siblings were compound heterozygotes for a novel missense mutation Gly685Arg and the nonsense mutation Arg49Stop. One patient carried a novel nonsense mutation Arg575Stop and a previously identified missense mutation Gly204Ser. In another patient, we identified a novel missense mutation Gln665Glu and a single-base deletion delA in Lys753. One patient of Turkish ancestry carried a newly identified homozygous A-to-G transition (ATG to GTG) abolishing the translation initiation codon of the myophosphorylase gene. These results suggest that Arg49Stop also is the most common genetic error associated with myophosphorylase deficiency in the German population. Our findings further demonstrate molecular heterogeneity of myophosphorylase deficiency among the clinically homogenous patients we studied.     

A novel ARC gene polymorphism is associated with reduced risk of Alzheimer’s disease

Alzheimer's disease (AD) is the most common neurodegenerative disease, and is clinically characterized by cognitive disturbances and the accumulation of the amyloid β (Aβ) peptides in plaques in the brain. Recent studies have shown the links between AD and the immediate-early gene Arc (activity-regulated cytoskeleton-associated protein), involved in synaptic plasticity and memory consolidation. For example, AD mouse models show a decreased expression of Arc mRNA in the brain. In additional, acute Aβ application to brain slices leads to a widespread ARC protein diffusion, unlike the normal defined localization to synapses. In this study, we investigated genetic variation in human ARC and the risk of developing AD. To this end, we genotyped 713 subjects diagnosed with AD and 841 controls without dementia. ARC was sequenced in a group of healthy individuals, and seven previously known SNPs and three novel SNPs were identified. Two of the newly found SNPs were intronic and one, +2852(G/A), was located in the 3'UTR. Three tag SNPs were selected, including the novel SNP +2852(G/A), to relate to risk of AD, Mini Mental State Examination (MMSE) scores and cerebrospinal fluid (CSF) biomarker levels of total tau (T-tau), hyperphosphorylated tau181 (P-tau(181)) and Aβ(1-42). The AA genotype of the newly found 3'-UTR SNP +2852(A/G), was associated with a decreased risk of AD (p (c)?=?0.005; OR?=?0.74; 95?% CI: 0.61-0.89). No associations of single SNPs or haplotypes with MMSE score or CSF biomarkers were found. Here we report a novel ARC SNP associated with a reduced risk of developing AD. To our knowledge, this is the first study associating a gene variant of ARC with any disease. The location of the SNP within the 3'UTR indicates that dendritic targeting of ARC mRNA could be involved in the molecular mechanisms underlying this protective function. However, further investigation of the importance of this SNP for ARC function, ARC processing and the pathology of AD is needed.