CASP-9: A susceptibility locus for multiple sclerosis in Italy.

Caspase-9 is a primary effector CASP that executes programmed cell death, which plays an important role in the development of multiple sclerosis (MS). Polymorphisms in the CASP-9 gene may influence its activity, thereby modulating the susceptibility to MS. To test this hypothesis, we evaluated a SNP in the CASP-9 gene in a set of Italian patients from Southern Italy and healthy control subjects. Our results suggest that the presence of the G/G genotype represents a higher risk factor in our MS population and a differential production of CASP-9 might be a contributory factor in determining the severity of MS.

The role of VLA4 polymorphisms in multiple sclerosis: an association study.

Lymphocyte and monocyte brain infiltration determines inflammation in multiple sclerosis. The trafficking of these cells into the CNS results from the VLA-4 binding with its ligand on brain endothelial cells. MS patients treated with an antibody against the alpha-4 subunit, which inhibits this interaction, prevents brain lesion development. We investigated the association between VLA-4 gene polymorphisms and MS in a study on 275 patients and 255 controls. No differences were detected, thus suggesting that these polymorphisms are not a significant genetic risk factor for susceptibility to MS in Italy.

Investigating the role of brain-derived neurotrophic factor in relapsing-remitting multiple sclerosis.

Multiple sclerosis (MS) is a common, heterogeneous disorder of the central nervous system with a complex trait composed of both genetic and environmental factors. Recently, scientific interest has increased in defining factors that possibly contribute to brain functional plasticity; the results might be useful to assess the relationship between MS lesion burden and clinical events, as well as explaining the well-known phenotypic heterogeneity of the disease. In this study, we explored the effect of the Val66Met brain-derived neurotrophic factor (BDNF) functional polymorphism on cognitive performances and volumetric measurements obtained by magnetic resonance imaging of the brain in a selected population of relapsing-remitting MS (RRMS) patients, with relatively short disease duration and minimal clinical disability, compared to gender, age and educational-level matched healthy subjects. We found that in the RRMS group, the BDNF Met-allele was significantly associated with the lower volume of cerebral grey matter (GM) (P = 0.005). Furthermore, a significant (P = 0.013) interaction effect between 'MS-status' and the BDNF genotype was found for GM volumes, with the result that patients carrying the BDNF Met-allele showed a higher risk of developing global GM atrophy than the homozygous Val/Val. No BDNF-related impact on global neuropsychological functions resulted in either RRMS patients or controls. Our data seem to be consistent with the reported influence of BDNF in neuronal plasticity, thus suggesting that the Met-allele might have a negative prognostic effect on cortical morphometry in RRMS patients.

APOE epsilon variation in multiple sclerosis susceptibility and disease severity: some answers.

BACKGROUND: Previous studies have examined the role of APOE variation in multiple sclerosis (MS), but have lacked the statistical power to detect modest genetic influences on risk and disease severity. The meta- and pooled analyses presented here utilize the largest collection, to date, of MS cases, controls, and families genotyped for the APOE epsilon polymorphism. METHODS: Studies of MS and APOE were identified by searches of PubMed, Biosis, Web of Science, Cochrane Review, and Embase. When possible, authors were contacted for individual genotype data. Meta-analyses of MS case-control data and family-based analyses were performed to assess the association of APOE epsilon genotype with disease risk. Pooled analyses of MS cases were also performed to assess the influence of APOE epsilon genotype on disease severity. RESULTS: A total of 22 studies (3,299 MS cases and 2,532 controls) were available for meta-analysis. No effect of epsilon2 or epsilon4 status on MS risk was observed (summary OR 1.14, 95% CI 0.96-1.34 and OR 0.89, 95% CI 0.78-1.01). Results obtained from analyses of APOE genotypes in 1,279 MS families were also negative (p = 0.61). Finally, results from pooled analyses of 4,048 MS cases also argue strongly that APOE epsilon status does not distinguish a relapsing-remitting from primary progressive disease course, or influence disease severity, as measured by the Expanded Disability Status Scale and disease duration. CONCLUSION: Overall, these findings do not support a role for APOE in multiple sclerosis, and underscore the importance of using large sample sizes to detect modest genetic effects, particularly in studies of genotype-phenotype relationships.

Genetic variation in the myeloperoxidase gene and cognitive impairment in multiple sclerosis.

There is evidence that multiple sclerosis (MS) may associated with cognitive impairment in 25 to 40% of cases. The gene encoding myeloperoxidase (MPO) is involved in molecular pathways leading to beta-amyloid deposition. We investigated a functional biallelic (G/A) polymorphism in the promoter region (-463) of the MPO gene in 465 patients affected by MS, divided into 204 cognitively normal and 261 impaired. We did not find significant differences in allele or genotype distributions between impaired and preserved MS patients. Our findings suggest that MPO polymorphism is not a risk factor for cognitive impairment in MS.

A novel mutation (Thr116Ile) in the presenilin 1 gene in a patient with early-onset Alzheimer's disease.

We report a novel presenilin 1 (PSN1) mutation (Thr116Ile) in a woman with early onset Alzheimer's disease (AD). This mutation was not found in 100 healthy controls, indicating that this is not a common polymorphism. The patient presented with forgetfulness at age 45, followed over the next 3 years by a worsening of the memory loss and frequent episodes of confusion and spatial disorientation. Neuroimaging studies were consistent with AD. The analysis of the family's pedigree showed that the proband was apparently the only member affected. Because the early death of several close relatives (i.e. the mother and the grandmother) and the demonstration that the father is not a mutation carrier, it is suggested that either a de novo mutation or a censor effect might have occurred. Our finding supports the indication that PSN1 mutations should be searched for in early-onset AD, particularly when a censor effect precludes a precise genetic analysis.

GABA(B) receptor 1 polymorphism (G1465A) is associated with temporal lobe epilepsy.

BACKGROUND: Dysfunction of gamma-aminobutyric acid (GABA) (B) receptors has been implicated in the pathogenesis of temporal lobe epilepsy (TLE). OBJECTIVE: To evaluate the genetic contribution of cloned human GABA(B) receptors to TLE. METHODS: The authors genotyped 141 patients (78 women and 63 men; mean age = 49.1 +/- 18.0 years) with nonlesional TLE and 372 age- and sex-matched normal individuals for the known polymorphism G1465A in the human GABA(B) receptor 1 [GABA(B[1])] gene. RESULTS: There was a highly significant overrepresentation of the G1465A heterozygote in patients with TLE compared with controls. The A/G genotype was found in 17% of the 141 patients with TLE and in only 0.5% of the 372 controls (p < 0.0001). The authors also found that patients carrying the A allele had a significantly higher risk (p = 0.003, OR = 6.47, 95% CI = 2.02 to 20.76) of developing drug-resistant TLE. Furthermore, the age at onset of seizures tended to be lower in patients with A/G genotype, but the difference was not significant. CONCLUSIONS: The results of this study indicate that the GABA(B[1]) polymorphism (G1465A) confers a highly increased susceptibility to TLE. Moreover, it seems to influence the severity of this common epileptic disorder.

Genetic association of alpha2-macroglobulin polymorphisms with AD in southern Italy.

The authors investigated the segregation of two polymorphisms of the alpha2-macroglobulin gene (A2M-I/D and A2M-Ile1000Val) in patients with sporadic AD from southern Italy. The A2M-I and A2M-Val1000 alleles were more frequent in cases than in controls, and this effect was independent from the APOE-epsilon4 status as well as from the age at onset of AD. Moreover, subjects carrying the A2M genotype I/I-Val/Val had a threefold increase of risk for AD. These data support a population-based susceptibility for AD linked to A2M polymorphisms.

Apolipoprotein E polymorphisms and the risk of nonlesional temporal lobe epilepsy.

PURPOSE: To evaluate whether the inheritance of the apolipoprotein E (ApoE) epsilon4 allele is a risk factor for nonlesional temporal lobe epilepsy (TLE), and to determine whether the newly described -491 A/T ApoE polymorphism may independently affect the risk of nonlesional TLE. METHODS: The study group consisted of 63 patients (35 women and 28 men; age at onset of epilepsy, 30.6 +/- 19.6 years; mean (+/-SD). All of them had received a diagnosis of nonlesional TLE after a detailed clinical, electroencephalographic, and brain magnetic resonance investigation. The ApoE polymorphisms were determined from blood samples by standard methods. The molecular study also was performed in 220 age- and sex-matched normal individuals. RESULTS: There were no differences between TLE patients and controls in either allelic or genotypic frequencies of the ApoE and -491A/T polymorphisms. Moreover, no effect of ApoE or -491A/T polymorphisms was found on the age at onset and severity of epilepsy. CONCLUSIONS: The allelic and genotypic frequencies of ApoE polymorphisms in Italian patients with nonlesional TLE are comparable to control values, indicating that ApoE polymorphisms are not a significant genetic risk factor for the occurrence of nonlesional TLE.

APOE and risk of cognitive impairment in multiple sclerosis.

OBJECTIVES: The APOE gene polymorphism and the -491 A/T polymorphism in its regulatory region have been associated with an increased risk for developing Alzheimer's disease. We examined these polymorphisms in multiple sclerosis (MS) patients, to determine if a genetic predisposition may explain the risk for developing cognitive decline in MS. MATERIAL AND METHODS: Eighty-nine relapsing-remitting and secondary progressive MS patients underwent to a full neuropsychological battery as well as to determination of APOE and -491 A/T polymorphisms. Genetic analysis was also performed in 107 population controls. RESULTS: The APOE polymorphism was not associated with the risk of cognitive impairment in MS patients. The AA genotype of the -491 A/T polymorphism in the APOE regulatory region was more frequent in cognitively impaired than in cognitively preserved MS subjects. CONCLUSION: The AA homozygous state of the -491 A/T polymorphism of the APOE regulatory region is associated with cognitive impairment in patients with MS.

Dopamine D2 receptor gene polymorphism and the risk of levodopa-induced dyskinesias in PD.

OBJECTIVE: To investigate whether polymorphisms in the genes for dopamine receptors D1 and D2 are associated with the risk of developing peak-dose dyskinesias in PD. BACKGROUND: Peak-dose dyskinesias are the most common side effects of levodopa therapy for PD. The identified predictors may only partially account for the risk of developing peak-dose dyskinesias because a substantial proportion of patients never develop peak-dose dyskinesias. Genetic factors could play a role in determining the occurrence of peak-dose dyskinesias. METHODS: A case-control study of 136 subjects with sporadic PD and 224 population control subjects. We studied three polymorphisms involving the dopamine receptor D1 gene and one intronic short tandem repeat polymorphism of the dopamine receptor D2 gene. RESULTS: The polymorphisms of the dopamine receptor D1 gene were not associated with the risk of developing PD or peak-dose dyskinesias. The 15 allele of the polymorphism of the dopamine receptor D2 gene was more frequent in parkinsonian subjects than in control subjects. More important, the frequency of both the 13 allele and the 14 allele of the dopamine receptor D2 gene polymorphism was higher in nondyskinetic than in the dyskinetic PD subjects. The risk reduction of developing peak-dose dyskinesias for PD subjects carrying at least 1 of the 13 or 14 alleles was 72% with respect to the PD subjects who did not carry these alleles. CONCLUSIONS: Certain alleles of the short tandem repeat polymorphism of the dopamine receptor D2 gene reduce the risk of developing peak-dose dyskinesias and could contribute to varying susceptibility to develop peak-dose dyskinesias during levodopa therapy.

Apolipoprotein E polymorphisms and Parkinson's disease.

The apolipoprotein E (APOE) gene polymorphism has been studied in Parkinson's disease (PD) with conflicting results. Recently, a newly described functional polymorphism in the regulatory region of the APOE gene, (-491 A/T), has been associated with late-onset Alzheimer's disease. We studied the association between these two polymorphisms of the APOE gene with PD in a sample of 126 PD patients and in 119 controls from the same geographic background. Allelic and genotypic frequencies were not different between PD cases and population controls for either the APOE or -491 A/T polymorphism. The age at onset of the disease was not different according to the specific genotypes of the two polymorphisms of the APOE gene.

Kufs' disease presenting as late-onset epilepsia partialis continua.

A 64-year-old woman, who had no personal or family history of neurologic diseases, had an 18-month history of epilepsia partialis continua (EPC) associated with a moderate intellectual deterioration and subtle extrapyramidal rigidity. There was no photosensitive response. A thorough laboratory investigation was unremarkable. A biopsy of the rectal mucosa revealed abundant fingerprint profiles diagnostic of Kufs' disease (KD). Our case expands the clinical picture of KD and suggests that such a diagnosis should be considered in adult-onset EPC.

Genetic heterogeneity of glucose-6-phosphate dehydrogenase deficiency in south-east Sicily.

In order to explore the nature of glucose-6-phosphate dehydrogenase (G6PD) deficiency in south-east Sicily, we have analysed the G6PD gene in 25 unrelated males with abnormal G6PD activity and/or electrophoretic mobility, by using the analysis of the appropriate PCR-amplified fragment of DNA and subsequent digestion by appropriate restriction-enzymes, looking for the presence of certain known G6PD mutations. We amplified the entire G6PD coding sequence into eight fragments, followed by single-strand conformation polymorphism (SSCP) analysis and sequencing of those individual fragments that were found to be abnormal by SSCP. Through these methods we found a total of twelve G6PD Mediterranean variants with the association of a silent mutation 1311 (also known as polymorphic site Bcl I), one G6PD Mediterranean without this association, four G6PD A-Val 68 and two G6PD Santamaria and five G6PD Chatham. In a subject with normal activity a mutation was found in exon 5, designated as G6PD Sao Borja. This is the first report on the molecular analysis of G6PD mutations in Sicily and we have obtained evidence for four distinct classes of variants.

Genetic heterogeneity of glucose-6-phosphate dehydrogenase deficiency revealed by single-strand conformation and sequence analysis.

We have carried out a systematic study of the molecular basis of glucose-6-phosphate dehydrogenase (G6PD) deficiency on a sample of 53 male subjects from Calabria, in southern Italy. Our sequential approach consisted of the following steps: (1) Partial biochemical characterization was used to pinpoint candidate known variants. The identity of these was then verified by restriction-enzyme or allele-specific oligonucleotide hybridization analysis of the appropriate PCR-amplified fragment. (2) On samples for which there was no obvious candidate mutation, we proceeded to amplify the entire coding region in eight fragments, followed by single-strand conformation polymorphism (SSCP) analysis of each fragment. (3) The next step was M13 phage cloning and sequencing of those individual fragments that were found to be abnormal by SSCP. Through this approach we have identified the molecular lesion in 51 of the 53 samples. In these we found a total of nine different G6PD-deficient variants, five of which (G6PD Mediterranean, G6PD A-, G6PD Coimbra, G6PD Seattle, and G6PD Montalbano) were already known, whereas four are new (G6PD Cassano, G6PD Cosenza, G6PD Sibari, and G6PD Maewo). G6PD Mediterranean is the commonest variant, followed by G6PD Seattle. At least seven of the variants are present, at polymorphic frequencies, in the Calabria region, and some have a nonrandom distribution within the region. This study shows that the genetic heterogeneity of G6PD deficiency in Calabria, when analyzed at the DNA level, is even greater than had been anticipated from biochemical characterization. The sequential approach that we have followed is fast and efficient and could be applied to other populations.

Glucose-6-phosphate dehydrogenase (G6PD) deficiency in the Albanian ethnic minority of Cosenza province, Italy.

The Albanian ethnic minority of the Cosenza province (Calabria, Southern Italy) is constituted by a population of 42,305 inhabitants living in 19 communes. The first presence of this population, in Southern Italy, dates back to the fifteenth century as a result of different immigrations. We have studied the G6PD in the population of this province by determining both the frequency of the G6PD-deficiency and the type of Gd(-) alleles in samples from 19 communes. The overall frequency estimate turned out to be 0.0294 and those of the 8 highland communes and of the 11 communes located in the valleys were 0.0242 and 0.033 respectively. Both the frequencies and the ratio between the frequencies of the different Gd(-) alleles are significantly different with respect to a previous study carried out on the non-Albanian population of the same areas. The high endogamy rate found among the grandparents' and among the parents of the probands living in the Albanian community, shows that this community is to a large extent reproductively isolated from the neighbouring populations, thus accounting for these differences.

Glucose-6-phosphate dehydrogenase (G6PD) deficiency in southern Italy: a study on the population of the Cosenza province.

35,660 healthy children attending secondary school in the Cosenza province, in the North of Calabria (Southern Italy), were screened for G6PD deficiency. Of 16,787 schoolboys, 209 were found to be G6PD deficient (1.24%). Of these, 99 (47.37%) had red cell G6PD activity below 5%, and they were classified as having the G6PD Mediterranean phenotype. The remaining 110 (52.63%), had a mild to moderate degree of deficiency, with an enzyme activity between 5 and 60%. Of these, 82 (74.55%) were electrophoretically normal, while 17 (15.45%) were electrophoretically fast and 11 (10.0%) were electrophoretically slow. The highest incidence of G6PD deficiency is on the Ionian Coast and along the Crati and Esaro river valleys, in good agreement with the distribution of the past malarial endemicity.