[Association between the VEGF -2578С/A polymorphism and amyotrophic lateral sclerosis in a Russian population]

Genetic predisposition plays an important role in the development of amyotrophic lateral sclerosis (ALS). One of the most promising candidate genes in ALS is the vascular endothelial growth factor (VEGF) gene. In a Russian population, 192 ALS patients (103 males and 89 females), aged from 20 to 83 years (52.0±13.4), were examined. A control group comprised 128 age- and sex-matched people. All individuals studied were Slavs. Polymorphism -2578С/А (rs699947) in the VEGF gene was studied by real-time PCR. It was shown that the genotype distribution was significantly different between the ALS and control groups (χ2=11.1; р=0.004); in the ALS cohort, the 2578A/A genotype was significantly more frequent (29.7% vs. 20.3%, p=0.04). The allele distribution was also significantly different between the two groups (χ2=4.4; р=0.036). The -2578А/А genotype increased risk of ALS (OR 1.66; 95% CI 1.03-2.29), and this pattern was most obvious in the male subgroup (OR=2.18; 95% CI 1.90-2.47). It was found the association of the 'risk' 2578A/A genotype with the earlier disease onset and rapid progression. Therefore, the results obtained in the study confirm the role of the VEGF gene in the pathogenesis of ALS in a Russian population.

[Advance of genetics and genomics in neurology]

Studies of genomic background of neurological disorders are very actual in view of their high population prevalence, severe course, serious impact on patients' disability and progressive mental and physical de-adaptation. In the paper, problems of genetic heterogeneity of hereditary neurological disorders and character of the respective genetic burden in the regions of Russian Federation are discussed in detail, a 'dynamic' type of mutations (increase in number of microsatellite repeats copies) attributable to many neurodegenerative diseases is analyzed, and achievements of Russian researchers in the identification of genes for hereditary neurological disorders and in the realization of pilot protocols of gene therapy are presented. Problems related to studies of genetic predisposition to common multifactorial diseases of the nervous system are discussed.

[Possibilities of treatment of dystonic syndromes with akineton]

Treatment of dystonia is a complex problem of current neurology due to the etiological and neurochemical heterogeneity of this clinical syndrome. Central cholinolytics is a most effective group of drugs for patients with dystonia and dystonic tremor. The authors present the results of the successful treatment with biperiden (akineton), a centrally active anticholinergic drug with additional peripheral choline- and ganglion-blocking effect in cervical dystonia. The time of response to treatment and duration of clinical effect, its possible predictors are analyzed. Perspectives of using cholinolytics in treatment of different forms of dystonic hyperkineses are discussed.

[Expression of GSK3B gene in peripheral blood in patient with Parkinson's disease]

Parkinson's disease (PD) is the second most common progressive neurodegenerative disorder characterized by the degeneration of dopaminergic neurons. Detecting changes in gene expression in untreated de novo patients with PD is important for understanding disease pathogenesis and for identifying biomarkers for preclinical stage of PD. In this study we investigate expression of gene of Glycogen synthase kinase-3 beta (GSK3B) in the peripheral blood of different groups of patients with neurological diseases using reverse transcription reaction and real-time polymerase chain reaction (PCR). Our results suggest that the expression levels of GSK3B can't serve as a biomarker for early stages of PD.

[Analysis of single nucleotide polymorphism rs415430 in the WNT3 gene in the Russian population with the Parkinson disease]

The Parkinson disease (PD) is the second most common progressive neurodegenerative disorder that arises due to degeneration of dopaminergic neurons. The causes of this disease are still unknown, but a number of genes involved in pathogenesis of familial and sporadic forms of PD has been identified. According to recent data of genome wide association studies (GWAS), single nucleotide polymorphisms (SNPs) in these genes (including MAPT locus) may play an important role in the development of PD. Therefore, we analyzed distribution of genotype frequencies of SNP rs415430 in the WNT3 gene in the Russian patients with sporadic PD and in the Russian population controls (OR = 0.84, Confidence Interval (95% CI) 0.58-1.23, p = 0.39). It was concluded that SNP rs415430 in the WNT3 gene was not associated with the risk of development of PD.

[Transcranial sonography in Parkinson's disease]

An abnormal hyperechogenecity of substantia nigra is thought to be the most characteristic sonographic feature in Parkinson's disease (PD). However specificity and sensitivity of the ultrasound method should be refined. Using transcranial sonography, authors have examined 168 patients with different clinical signs of parkinsonism, including 99 patients with idiopathic PD, and 56 patients without extrapyramidal disorders. Hyperechogenecity of substantia nigra was found in 93% of patients and in 14% of controls. It has been shown that this biomarker can successfully discriminate PD from a number of similar disorders (essential tremor, atypical parkinsonian syndromes). Sonographic features of late, early and genetically determined parkinsonism specifying some pathogenetic aspects of these pathologies are described. Taking into account the data obtained, transcranial sonography can be considered as a highly informative method in the differential and early diagnosis of PD.

[Hereditary spastic paraplegia type 4 (SPG4): clinical and molecular-genetic characteristics]

Hereditary spastic paraplegia (HSP), type 4, or SPG4, caused by various mutations in the spastin gene (SPAST) is the most common disorder in a heterogeneous group of autosomal dominant HSP's. We performed a search of SPAST mutations by routine methods (SSCP and subsequent direct sequencing of fragments with modified electrophoretic mobility) in a sample of 26 families with autosomal dominant HSP from different Russian regions. In six families, five of Russian and one of Tatar ethnicity, different SPAST mutations were detected. Three of the mutations, Arg431Stop, Gln280Arg FsX9 and Asn386Ser, were reported previously; the remaining three, Asp555Tyr, Thr369Thr and Asn184Thr, were novel. In the family with the Arg431Stop mutation, a linkage to SPG4 locus was also established, lod scores were 1,66 for D2S352 marker and 1,51 for D2S367. Another large family also showed a linkage to the SPG4 locus (lod scores 1,68 for D2S352, 2,17 for D2S367) but the mutation was not found which may be due to atypical SPAST mutations (large deletions etc) undetectable by routine methods of DNA analysis. Including this family, the proportion of the SPG4 in the sample is 27%, which is less than average literature data (40-45%). Most of our patients presented relatively late-onset "uncompicated" HSP, which was typical for SPG4, though different additional features in SPG4 patients were also known. One of our patients had very early-onset HSP and concomitant epilepsy. In two pedigrees, in which all available relatives were examined, some patients had mild signs of SPG4, even late in life.

[Analysis of the alpha-synuclein gene dosage variation associated with autosomal dominant form of ParkinsonTs disease]

Fifty-two patients that had ParkinsonTs disease with autosomal dominant type of inheritance were analyzed for the presence of duplications and triplications in exons 4--6 of alpha-synuclein gene using real-time PCR with Taq-Man probes. No mutations involving the examined exons dosage were revealed in alpha-synuclein gene. Thus, mutations modifying copy number of alpha-synuclein gene do not significantly affect the pathogenesis of the autosomal dominant form of ParkinsonTs disease in patients from Russia.

Gene therapy of amyotrophic lateral sclerosis

Two-year experiments were performed to evaluate the neurotrophic effect of hypoxia-inducible factors (vascular endothelial growth factor and angiogenin) expressed in recombinant human adenoviruses in amyotrophic lateral sclerosis. Randomized placebo-controlled trial demonstrated safety and good tolerability of the recombinant antiviral drugs. The life span of patients under conditions of hypoxia increased after treatment with the test drug, which was probably related to improved resistance of motoneurons. The presence of virus-neutralizing antibodies decreases the effectiveness of adenoviral vectors, which necessitates differential approach to the selection of patients and continuous monitoring of gene therapy.

[The role of apolipoprotein E in patients with amyotrophic lateral sclerosis (a clinical and genetic study)]

The apolipoprotein E (apoE) gene plays an important role in forming predisposition and modulating the course of Alzheimer's disease, primary parkinsonism and some other human neurodegenerative disorders. In this study, for the first time in the Russian population, we performed the analysis of genetic association of apoE gene variants in 62 patients with a sporadic form of amyotrophic lateral sclerosis (ALS) aged from 20 to 75 years (49.5+/-14.2); age at disease onset was from 18 to 74 years (47.1+/-15.2). No statistically significant differences in the distribution of apoE genotypes between patients and controls were found. It was shown that the frequency of the apoE-e2 allele was significantly higher in the young group characterized by more benign course of ALS (spinal variant, slow rate of progression of ALS and longer survival) as well as in patients with a more "benign" spinal form of the disease. On the contrary, the chance of carrying the apoE-e4 allele is higher in the older age group in which a prognostically more severe bulbar form is also more prevalent. Therefore, the apoE-e2 allele may be regarded as a neuroprotective factor in the development of neurodegenerative process in patients with ALS.

A common leucine-rich repeat kinase 2 gene mutation in familial and sporadic Parkinson's disease in Russia

A PARK8 form of Parkinson's disease (PD) is caused by a novel gene, leucine-rich repeat kinase 2 (LRRK2), and a single mutation G2019S was found in a proportion of LRRK2-associated cases of diverse ethnic origins. We performed the LRRK2 G2019S mutation analysis in 304 Russian patients with PD, including 291 sporadic and 13 autosomal dominant cases. The frequency of the LRRK2 G2019S was 0.7% amongst the sporadic patients (2/291) and 7.7% amongst familial PD (1/13). The mutation was also found in three unaffected relatives and absent in 700 control chromosomes. One patient carrying the LRRK2 G2019S was found earlier to have an additional mutation, a heterozygous duplication of exon 5 of the parkin gene. All patients carrying the LRRK2 G2019S exhibited typical levodopa-responsive parkinsonism, and severe levodopa-induced dyskinesia was observed in the patient carrying the LRRK2 and parkin mutations. There was notable variability in ages of the disease onset in G2019S carriers not explained by APOE genotypes. Two subsets of G2019S-positive patients had different PARK8 haplotypes suggesting that the LRRK2 G2019S in Russian patients had arisen independently on different chromosomes. Identification of common LRRK2 mutations in some PD patients without an overt family history has notable implications for genetic counseling.

[A PARK8 form of Parkinson's disease: a mutational analysis of the LRRK2 gene in Russian population]

A recently described form of Parkinson's disease - PARK8 - is caused by mutations in the novel LRRK2 gene on chromosome 12q12. The most common mutation in this gene is the substitution G2019S and we studied it for the first time in a large group of Russian Slavonic patients (311 patients) with Parkinson's disease including 295 sporadic and 16 familial cases. The mutation LRRK2-G2019S was identified in 1% of patients examined (3 cases) and was not found in a group of population control. The clinical picture of all patients with the LRRK2-G2019S mutation was typical for levodopa-responsive parkinsonism and age of disease onset varied widely (from 39 to 71 years). Two different PARK8-linked haplotypes were found in carriers of the mutation that suggested the independent origin of the G2019S mutation on different chromosomes. The identification of mutations in the LRRK2 gene in patients with "ordinary" sporadic Parkinson's disease has serious implications for medical genetic counseling and prognosis in respective families.

[The use of noben for correction of mitochondrial disorders in Friedrich's disease]

The results of treatment with noben (idebenon), an improved structural analogue of coenzyme Q10, of 34 patients with Friedrich's disease are presented. In all cases, the clinical diagnosis was confirmed by the presence of a typical mutation, an expansion of trinucleotide GAA-repeats, in the FRDA gene. All patients received noben as a main drug in dosage 5 mg/kg daily during 3 months. An examination of the patients included modern laboratory and instrumental methods, analysis of levels of lactic and pyruvic acids and their ratio in the peripheral blood. Also parameters of lipid peroxidation and mitochondrial dehydrogenase activity in peripheral lymphocytes were studied. Positive changes were found in the majority of patients for muscle strength in extremities, tolerability to physical loadings, general fatigue, movement activity, speech and coordination functions, along with significant improvement of biochemical and cytochemical status. The results obtained suggest a positive effect of noben on cell energy metabolism in this severe disorder from the group of mitochondrial cytopathies.

[7-year experience in usage of mirapex in patients with different forms of primary parkinsonism]

The results of mirapex (pramipexol) treatment of 402 patients with Parkinson's disease and juvenile parkinsonism during the period from 6 months to 7 years are summarized. Mirapex was used in monotherapy as well as in combination with levadopa and other antiparkinsonic drugs. The drug was well tolerated and effective in rest tremor, hypokinesia, muscle rigidity and depression, the more pronounced effect being seen at the early stage of the disease. The use of mirapex allows an effective control of motor fluctuations developing during long-term continuous levodopa therapy. The results obtained characterize mirapex as a drug of choice in the treatment of juvenile parkinsonism. In case of a break in mirapex treatment, the recommencement of treatment usually is not accompanied by reduced sensitivity to drug effect.

[Neurodegenerative alterations induced by MPTP neurotoxin in senescence accelerated mice essay]

Behavioral modifications and alterations in biochemical pathways induced by neurotoxin MPTP in Senescence Accelerated Mice (SAM) brains are discussed. MPTP injections lead to specific injuries of dophaminergic neurons and to reinforcement of oxidative stress conditions. The ability of neuropeptide carnosine to protect animals from oxidative injuries induced by MPTP injections is also described.

[Molecular genetic analysis of hereditary neurodegenerative diseases]

The review summarizes the results of a decade of molecular genetic studies of several high-incidence hereditary neurodegenerative diseases, including primary parkinsonism, various forms of hereditary dystonia and ataxia, polyglutamine disorders, hepatolenticular degeneration, essential tremor, etc. Various relevant mutations were studied. The character and frequencies of particular mutations and the corresponding genetic disorders were established for the Russian population. Particular genotypes were associated with various clinical variants of the diseases. Genetic loci were identified for several unique hereditary diseases of the nervous system (X-linked cerebellar hypoplasia, an atypical form of autosomal recessive muscular dystrophy, etc.). Nosological positions of the relevant clinical forms were clarified on the basis of the molecular genetic data. Protocols were developed for direct or indirect DNA diagnostics of the diseases under study to improve medical genetic counseling and prevention of new disease cases in affected families.

[Voluntary postural control learning with a use of visual bio-feedback in patients with spinocerebellar degenerations]

The study aimed at evaluation of possibility and features of voluntary postural control learning using biofeedback from a force platform in patients with spinocerebellar ataxias. Thirty-seven patients with different forms of spinocerebellar degenerations and 13 age-matched healthy subjects were trained to shift the center of pressure (CP) during several stabilographic computer games which tested an ability to learn 2 different types of voluntary postural control: general strategy and precise coordination of CP shifting. Despite the disturbances of static posture and ability for voluntary control of CP position, patients with spinocerebellar degenerations can learn to control a vertical posture using biofeedback on stabilogram. In contrast to healthy subjects, improvement of coordination in the training process does not exert a significant influence on the static posture characteristics, in particular on lateral CP oscillations. The results obtained suggest involvement of the cerebellum in both types of postural control that distinguishes them from pathology caused by motor cortex and nigro-striatal system involved only in one type of postural control.

[Clinical and genetic analysis of juvenile parkinsonism in Russia]

Clinical and genetic analysis of juvenile parkinsonism was performed in 26 sibs from 20 families. Heterogeneity of the disorder was observed. Mutations in the parkin gene (locus PARK2, chromosome 6q25.2-27), with the prevalence of deletions over point mutations, have been identified in 41%. The comparative clinical analyses of patients examined confirmed the phenotypical polymorphism of "parkinopathy". We also showed the absence of asymmetric manifestation--an important and underestimated so far sign of the disease. The results of the study may be considered as a valuable clue to the clinical diagnosis of parkin-related juvenile parkinsonism in Russian population and implemented for mutation screening and medico-genetic counseling of affected families.

[Clinical and stabilometric analysis of postural instability in Parkinson's disease]

A disturbance of postural control is one of the most invalidating symptoms of Parkinson's disease (PD), and mechanisms underlying its development have not been so far elucidated. To specify the postural control features in different PD forms, clinico-neurophysiological analysis was conducted in 61 patients divided into 3 groups according to PD forms: tremor-rigid, rigid-tremor and akinetic-rigid. Dissociation between clinical expression of postural instability and its stabilometric reflection--the square of statokinesogram was found, indicating importance of differentiated approach in performance of stabilometric analysis in patients with different PD forms. The square of statokinesogram may be regarded as a neurophysiological marker of postural instability only in patients with rigid forms, in tremor parkinsonian phenotypes an increased square of stabilogram being mainly a stabilometric reflection of tremor. The importance of stabilometric test performance with cognitive loading, allowing switching out of voluntary posture control, is shown. Possible neuromediator mechanisms involved in postural instability in PD are discussed.

[Cytochemical activity of mitochondrial enzymes in Parkinson's disease]

Using cytochemical computerized morphometric method, activity of the key enzymes of energetic metabolism (succinate dehydrogenase, alpha-glycerophosphate dehydrogenase, malate dehydrogenase, glutamate dehydrogenase and lactate dehydrogenase) was studied in blood lymphocytes of 75 patients with Parkinson's disease and 15 healthy controls. The signs of systemic mitochondrial insufficiency, which correlated with the disease duration and severity, were found in all the patients, including those with juvenile parkinsonism. These data may provide a basis for introducing cytochemical monitoring as well as for administration of modern "mitochondrial" drugs (yantavit, coenzyme Q10, L-carnitine, etc).

[Molecular genetic analysis of essential tremor]

Essential tremor (ET) is the most common extrapyramidal disorder of the central nervous system with autosomal dominant transmission in the majority of cases and age-dependent penetrance of the mutant gene. In a number of cases, it shares some phenotypic features with autosomal dominant idiopathic torsion dystonia (locus DYT1 on chromosome 9q32-34) and is genetically heterogeneous: distinct variants of ET were mapped to chromosomes 3q13 (ETM1) and 2p22-25 (ETM2). We performed studies of candidate loci in a group of Slavonic (11 patients) and Tajik (19 patients) families with ET. Mutational analysis of the DYT gene in probands did not reveal the major deletion 946-948delGAG characteristic of idiopathic torsion dystonia, which allows one to genetically distinguish the studied hereditary forms of ET and torsion dystonia. Based on analysis of genetic linkage in informative Tajik pedigrees with ET, linkage to locus ETM1 on chromosome 3q13 was established in four families. Maximum pairwise Lod score was 2.46 at recombination fraction of theta = 0.00; maximum combined multipoint Lod score was 3.35 for marker D3S3720 and a common "mutant" haplotype for markers D3S3620, D3S3576, and D3S3720 allowed us to locate a mutant gene in a relatively narrow chromosome region spanning 2 cM. In one informative pedigree with ET, both candidate loci ETM1 and ETM2 were definitely excluded on the basis of negative Lod scores obtained by linkage estimations, which testifies to the existence of another distinct gene for autosomal dominant ET.