Genomic variants and inferred biological processes in multiplex families with Tourette syndrome

BACKGROUND

Tourette syndrome is a developmental neuropsychiatric disorder. Its etiology is complex and elusive, although an important role of genetic factors has been established. The aim of the present study was to identify the genomic basis of Tourette syndrome in a group of families with affected members in 2 or 3 generations.

METHODS

Whole-genome sequencing was performed followed by co-segregation and bioinformatic analyses. Identified variants were used to select candidate genes, which were then subjected to gene ontology and pathway enrichment analysis.

RESULTS

The study group included 17 families comprising 80 patients with Tourette syndrome and 44 healthy family members. Co-segregation analysis and subsequent prioritization of variants pinpointed 37 rare and possibly pathogenic variants shared among affected individuals within a single family. Three such variants, in the ALDH2, DLD and ALDH1B1 genes, could influence oxidoreductase activity in the brain. Two variants, in SLC17A8 and BSN genes, were involved in sensory processing of sound by inner hair cells of the cochlea. Enrichment analysis of genes whose rare variants were present in all patients from at least 2 families identified significant gene sets implicated in cell-cell adhesion, cell junction assembly and organization, processing of sound, synapse assembly, and synaptic signalling processes.

LIMITATIONS

We did not examine intergenic variants, but they still could influence clinical phenotype.

CONCLUSION

Our results provide a further argument for a role of adhesion molecules and synaptic transmission in neuropsychiatric diseases. Moreover, an involvement of processes related to oxidative stress response and sound-sensing in the pathology of Tourette syndrome seems likely.

Polygenic risk score-based phenome-wide association study identifies novel associations for Tourette syndrome

Tourette Syndrome (TS) is a complex neurodevelopmental disorder characterized by vocal and motor tics lasting more than a year. It is highly polygenic in nature with both rare and common previously associated variants. Epidemiological studies have shown TS to be correlated with other phenotypes, but large-scale phenome wide analyses in biobank level data have not been performed to date. In this study, we used the summary statistics from the latest meta-analysis of TS to calculate the polygenic risk score (PRS) of individuals in the UK Biobank data and applied a Phenome Wide Association Study (PheWAS) approach to determine the association of disease risk with a wide range of phenotypes. A total of 57 traits were found to be significantly associated with TS polygenic risk, including multiple psychosocial factors and mental health conditions such as anxiety disorder and depression. Additional associations were observed with complex non-psychiatric disorders such as Type 2 diabetes, heart palpitations, and respiratory conditions. Cross-disorder comparisons of phenotypic associations with genetic risk for other childhood-onset disorders (e.g.: attention deficit hyperactivity disorder [ADHD], autism spectrum disorder [ASD], and obsessive-compulsive disorder [OCD]) indicated an overlap in associations between TS and these disorders. ADHD and ASD had a similar direction of effect with TS while OCD had an opposite direction of effect for all traits except mental health factors. Sex-specific PheWAS analysis identified differences in the associations with TS genetic risk between males and females. Type 2 diabetes and heart palpitations were significantly associated with TS risk in males but not in females, whereas diseases of the respiratory system were associated with TS risk in females but not in males. This analysis provides further evidence of shared genetic and phenotypic architecture of different complex disorders.

Cathepsin B p.Gly284Val Variant in Parkinson’s Disease Pathogenesis

Parkinson’s disease (PD) is generally considered a sporadic disorder, but a strong genetic background is often found. The aim of this study was to identify the underlying genetic cause of PD in two affected siblings and to subsequently assess the role of mutations in Cathepsin B (CTSB) in susceptibility to PD. A typical PD family was identified and whole-exome sequencing was performed in two affected siblings. Variants of interest were validated using Sanger sequencing. CTSB p.Gly284Val was genotyped in 2077 PD patients and 615 unrelated healthy controls from the Czech Republic, Ireland, Poland, Ukraine, and the USA. The gene burden analysis was conducted for the CTSB gene in an additional 769 PD probands from Mayo Clinic Florida familial PD cohort. CTSB expression and activity in patient-derived fibroblasts and controls were evaluated by qRT-PCR, western blot, immunocytochemistry, and enzymatic assay. The CTSB p.Gly284Val candidate variant was only identified in affected family members. Functional analysis of CTSB patient-derived fibroblasts under basal conditions did not reveal overt changes in endogenous expression, subcellular localization, or enzymatic activity in the heterozygous carrier of the CTSB variant. The identification of the CTSB p.Gly284Val may support the hypothesis that the CTSB locus harbors variants with differing penetrance that can determine the disease risk.

Enhancing neuroimaging genetics through meta-analysis for Tourette syndrome (ENIGMA-TS): A worldwide platform for collaboration

Tourette syndrome (TS) is characterized by multiple motor and vocal tics, and high-comorbidity rates with other neuropsychiatric disorders. Obsessive compulsive disorder (OCD), attention deficit hyperactivity disorder (ADHD), autism spectrum disorders (ASDs), major depressive disorder (MDD), and anxiety disorders (AXDs) are among the most prevalent TS comorbidities. To date, studies on TS brain structure and function have been limited in size with efforts mostly fragmented. This leads to low-statistical power, discordant results due to differences in approaches, and hinders the ability to stratify patients according to clinical parameters and investigate comorbidity patterns. Here, we present the scientific premise, perspectives, and key goals that have motivated the establishment of the Enhancing Neuroimaging Genetics through Meta-Analysis for TS (ENIGMA-TS) working group. The ENIGMA-TS working group is an international collaborative effort bringing together a large network of investigators who aim to understand brain structure and function in TS and dissect the underlying neurobiology that leads to observed comorbidity patterns and clinical heterogeneity. Previously collected TS neuroimaging data will be analyzed jointly and integrated with TS genomic data, as well as equivalently large and already existing studies of highly comorbid OCD, ADHD, ASD, MDD, and AXD. Our work highlights the power of collaborative efforts and transdiagnostic approaches, and points to the existence of different TS subtypes. ENIGMA-TS will offer large-scale, high-powered studies that will lead to important insights toward understanding brain structure and function and genetic effects in TS and related disorders, and the identification of biomarkers that could help inform improved clinical practice.

Motor neurons loss in Parkinson Disease: An electrophysiological study (MUNE)

The aim of this study was to evaluate the involvement of a peripheral motor neuron in Parkinson Disease (PD) using the motor unit number estimation (MUNE) method, which reflects motor unit loss in motor neuron diseases. Multipoint incremental MUNE method was calculated in abductor pollicis brevis (APB) and abductor digiti minimi (ADM) in forty one (41) patients with PD and forty five (45) healthy volunteers. From the analysis, the MUNE of APB was lower in PD than in the control group, especially in the sub-group aged 60 years or older. MUNE was negatively correlated with the age of patientsfor APB, but not with the duration of the disease and advancement of PD. The loss of motor units in sporadic Parkinson's disease revealed by multipoint incremental MUNE method is considered a sign of lower motor neuron involvement, however, loss of motor neurons is slight and does not manifest equally in all muscles . Thus, the results from this experiment should be treated with concern, as it could be a landmark for further experiments.

Tonic Tics in Gilles de la Tourette Syndrome

AIM

Tonic tics (TTs) are a part of a clinical picture of Gilles de la Tourette syndrome (GTS) and manifest themselves as sustained and isometric contraction of a muscle group devoid of the movement effect or accompanied by only slight visible motion. The aim of this study was to evaluate the prevalence and phenomenology of TTs, and to assess the clinical associations of TTs with tic severity and comorbidities in patients with GTS.

METHODS

We performed a one-time registration study in a cohort of 241 consecutive outpatients with GTS aged 5 to 50 years (188 males, 153 patients under the age of 18 years). All patients were personally interviewed and examined.

RESULTS

TTs occurred in 85.2% of adults and 63.9% of children and adolescents. Most frequently reported types of TTs were tensing of the abdomen (58.7%), neck (52.7%), and upper limbs (50.3%). Multivariate statistical analysis showed a significant correlation between TTs and the total number of simple tics, total number of complex tics, and age at evaluation. In the group of children and adolescents, an additional significant variable was the duration of GTS. In the group of adults, significant parameters were total number of simple tics, total number of complex tics, peak tic severity ever experienced, premonitory urges, and the presence of dystonic tics.

CONCLUSION

TTs belong to the tic spectrum, common and early symptoms of GTS, are associated with overall a greater number of tics which are more severe, and with more comorbidities.

Blocking Tics in Gilles de la Tourette Syndrome

Introduction: Patients with Gilles de la Tourette syndrome (GTS) may experience blocking tics (BTs) defined as recurrent, brief cessations of motor acts. The aim of this study was to assess the prevalence, age of onset, and clinical correlates of BTs in GTS patients.

Materials and Methods: We performed a one-time registration study in a cohort of 195 consecutive GTS patients aged 5–66 years (mean age: 15.0 ± 9.2; 47 females, 24.1%). All patients were personally interviewed and examined.

Results: At least one BT occurred at some point in the lifetime of 73 patients (37.4%) with a mean age of onset of 10.4 ± 5.9 years. BTs occurred an average of 4.8 ± 5.3 years after tic onset. The most common BT was cessation of walking (n = 59, 80.8%), followed by speech (n = 19, 26.0%), running (n = 18, 24.7%), and writing (n = 9, 12.3%). Most of the patients (n = 52, 71.2%) reported cessation of only one activity. Clinical associations of BTs included more severe tics, overall greater number of tics, and, to a lesser extent, higher age at evaluation and comorbid obsessive-compulsive disorder.

Conclusions: BTs represent complex tics, early and common symptoms of GTS, and are associated with a more severe form of GTS.

Frequency of mutations in PRKN, PINK1, and DJ1 in Patients With Early-Onset Parkinson Disease from neighboring countries in Central Europe

INTRODUCTION

Approximately 10% of patients with Parkinson disease (PD) present with early-onset disease (EOPD), defined as diagnosis before 50 years of age. Genetic factors are known to contribute to EOPD, with most commonly observed mutations in PRKN, PINK1, and DJ1 genes. The aim of our study was to analyze the frequency of PRKN, PINK1, and DJ1 mutations in an EOPD series from 4 neighboring European countries: Czech Republic, Germany, Poland, and Ukraine.

METHODS

Diagnosis of PD was made based on UK Brain Bank diagnostic criteria in departments experienced in movement disorders (1 from Czech Republic, 1 from Germany, 9 from Poland, and 3 from Ukraine). EOPD was defined as onset at or before 50 years of age. Of the 541 patients recruited to the study, 11 were Czech, 38 German, 476 Polish, and 16 Ukrainian. All cohorts were fully screened with Sanger sequencing for PRKN, PINK1, and DJ1 and multiplex ligation-dependent probe amplification for exon dosage.

RESULTS

PRKN homozygous or double heterozygous mutations were identified in 17 patients: 1 Czech (9.1%), 1 German (2.6%), 14 Polish (2.9%), and 1 Ukrainian (6.3%). PINK1 homozygous mutations were only identified in 3 Polish patients (0.6%). There were no homozygous or compound heterozygous DJ1 mutations in analyzed subpopulations. One novel variant in PRKN was identified in the Ukrainian series.

CONCLUSION

In the analyzed cohorts, mutations in the genes PRKN, PINK1, and DJ1 are not frequently observed.

Validation of the Polish version of the Movement Disorder Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS)

BACKGROUND

In 2008, the Movement Disorders Society (MDS) published a new Unified Parkinson's Disease Rating Scale (MDS-UPDRS) as the official benchmark scale for Parkinson's Disease (PD). We have translated and validated the Polish version of the MDS-UPDRS, explored its dimensionality, and compared it to the original English one.

METHODS

The MDS-UPDRS was translated into Polish by a team of Polish investigators led by JS and GO. The back-translation was completed by colleagues fluent in both languages (Polish and English) who were not involved in the original translation, and was reviewed by members of the MDS Rating Scales Programme. Then the translated version of the MDS-UPDRS underwent cognitive pretesting, and the translation was modified based on the results. The final translation was approved as the Official Working Document of the MDS-UPDRS Polish version, and was tested on 355 Polish PD patients recruited at movement disorders centres all over Poland (at Katowice, Gdańsk, Łódź, Warsaw, Wrocław, and Kraków). Confirmatory and explanatory factor analyses were applied to determine whether the factor structure of the English version could be confirmed in the Polish version.

RESULTS

The Polish version of the MDS-UPDRS showed satisfactory clinimetric properties. The internal consistency of the Polish version was satisfactory. In the confirmatory factor analysis, all four parts had greater than 0.90 comparative fit index (CFI) compared to the original English MDS-UPDRS. Explanatory factor analysis suggested that the Polish version differed from the English version only within an acceptable range.

CONCLUSIONS AND CLINICAL IMPLICATIONS

The Polish version of the MDS-UPDRS meets the requirements to be designated as the Official Polish Version of the MDS-UPDRS, and is available on the MDS web page. We strongly recommend using the MDS-UPDRS instead of the UPDRS for research purposes and in everyday clinical practice.

Association of a Variant of CNR1 Gene Encoding Cannabinoid Receptor 1 With Gilles de la Tourette Syndrome

Background

Gilles de la Tourette syndrome (GTS) is a neuropsychiatric disorder of unknown etiology, although a major role of genetic factors has been established. Cannabis-based medicines may alleviate GTS-associated tics and variants of CNR1 gene encoding central cannabinoid receptor (CB1) are believed to be a risk factor for the development of some neurodevelopmental diseases. Our aim was to test the association of selected CNR1 gene variants with GTS.

Material and Methods

The cohort of GTS cases comprised 262 unrelated patients aged 3–53 years (mean age: 18.3 ± 9.1 years; 204 males (77.9%), 126 (48.1%) adults defined as ≥18 years). As a control group we enrolled 279 unrelated, ethnically and gender matched individuals with no diagnosed mental, neurological or general disorder, aged 13–54 years (mean age: 22.5 ± 3.0 years; 200 males, (74.1%). Both study and control groups were selected from Polish population, which is ethnically homogenous subgroup of Caucasian population. Four single nucleotide polymorphisms (SNPs) in CNR1 were selected: rs2023239, rs2180619, rs806379, and rs1049353 based on minor allele frequency in general population >15%. These variants were genotyped using a real-time quantitative polymerase chain reaction system (TaqMan SNP genotyping assay).

Results

We found significant association of GTS clinical phenotype with rs2023239 variant. Minor allele C and CT+CC genotypes were found significantly more often in GTS patients compared to controls (17.4 vs 11.1%, p=0.003 and 32.8 vs 20.4%, p=0.001, respectively), and the difference remained significant after correction for multiple testing. C allele of rs2023239 polymorphism of the CNR1 gene was associated with the occurrence of tics. There were no statistically significant associations for rs806379, rs1049353 or rs2180619 variants.

Conclusion

Our findings suggest that C allele of rs2023239 polymorphism of the CNR1 gene is a risk factor of GTS in Polish population. The variant can be potentially associated with abnormal endocannabinoid transmission, which is suspected to be one of the causes of GTS.

Clinical phenotype heterogeneity in a family with ε-sarcoglycan gene mutation

AIM OF THE STUDY

This paper describes six cases of patients with myoclonus-dystonia syndrome who are members of a family in which an SGCE gene mutation has been confirmed.

CLINICAL RATIONALE FOR THE STUDY

Myoclonus-dystonia syndrome is a very rare disease, with an incidence in Europe of about 2 in every million. Due to the fact that only a few case reports of this illness are accessible in the literature, the material we collected seems to be valuable for clinical practice.

MATERIALS AND METHODS

A history was taken, and physical and genetic examinations of the patients were performed. Furthermore, the clinical examination of three patients was video-recorded.

RESULTS

The clinical picture of the disease varied significantly between the described individuals, from a healthy carrier of the SGCE mutation to patients presenting mild to moderate symptoms. The differences concerned the age at onset of the disease, the initial symptoms, the intensity of involuntary movements, and the predominant symptoms. In addition to the typical movement disorders which are myoclonus and dystonia, in the described family there was also the coexistence of epilepsy, obsessive-compulsive behaviour, dyslexia, dysgraphia, non-harmonious development of cognitive processes, as well as mild phenotypic features of muscular dystrophy. The mutation (NM_001099401.2:c.806-809delACTG) found in the presented family has not been described elsewhere.

CONCLUSIONS AND CLINICAL IMPLICATIONS

Our description of six cases of patients demonstrates the heterogeneity of the natural course of the disease, even in patients with the same mutation. It seems reasonable to regularly examine relatives of patients with myoclonus-dystonia syndrome, who should be observed for involuntary movements as well as non-motor symptoms.

Dystonic tics in patients with Gilles de la Tourette syndrome

CLINICAL RATIONALE FOR THE STUDY

Gilles de la Tourette syndrome (GTS) is a childhood onset disorder characterised by motor and vocal tics. Different types of motor tics may occur in GTS, including dystonic tics (DTs). Although DTs have been recognised as part of GTS symptomatology, little is known about their risk factors or about how often and at what age they appear in affected individuals.

AIM OF THE STUDY

The aim of our study was to investigate lifetime prevalence and clinical correlations of DTs in a Polish cohort of GTS patients.

MATERIAL AND METHODS

We performed a prospective, one-registration study in a cohort of 207 consecutive ambulatory patients (mean age: 16.5 ± 9.4 years, 131 children, 162 males) with GTS. Duration of GTS was 9.0 ± 8.0 years (range: 1-39 years). DTs were diagnosed during the interview. DTs were defined as slower and lasting longer than typical clonic tics, abnormal dystonia-like movements that led to a sustained, but not fixed, posture.

RESULTS

DTs occurred at some point in the lifetime of 73.9% (n = 153) of patients. The prevalence of DTs in adults and children was almost the same (p = 0.963). Age at onset of DTs was 9.9 ± 5.2 years with the most frequent onset in children (7-11 years, 74.4%, n = 64), followed by adolescence (12-18 years; 17.4%, n = 15) and adulthood (≥ 18 years, 8.1%, n = 7). DTs occurred 3.7 ± 4.2 years after tic onset. On average, patients suffered from 1.8 ± 1.7 types of DTs. The most frequent manifestations of DTs were: eyes (tightening resembling blepharospasm 84.3%, n = 129 and oculogyric crisis 45.8%, n = 70), trunk (dystonic postures 59.5%, n = 91), jaw (bruxism 34.6%, n = 53), neck (30.7%, n = 47), upper limb (26.1%, n = 40), and foot (20.9%, n = 32). Multivariate logistic regression analysis showed significant associations of DTs with the total number of simple, and the total number of complex, tics.

CONCLUSIONS AND CLINICAL IMPLICATIONS

DTs are early and frequent symptoms of GTS. They tend to localise in the facial area. DTs occur more frequently in individuals with a higher number of tics and probably add to the global impairment caused by tics.

Prevalence and Clinical Correlates of Self-Harm Behaviors in Gilles de la Tourette Syndrome

Introduction: Major symptoms of Gilles de la Tourette syndrome (GTS) are tics, but in 90% of cases, psychiatric comorbidities occur. Self-harm behaviors (SHBs) could result from deliberate action and unintentional injury from tics. Methods: We examined 165 consecutive GTS patients aged 5 to 50 years (75.8% males). The median duration of GTS was 14 years (interquartile range, 9-22 years). The patients were evaluated for GTS and comorbid mental disorders according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision. Self-harm behavior was diagnosed during the interview. To determine a direct relationship between SHB and clinical variables, we conducted two analyses, at the time of evaluation and lifetime. We also compared the group of children and adults with SHB. We also tried to distinguish between deliberate (non-tic-related SHB) and accidental (tic-related SHB). Results: Lifetime SHB was reported by 65 patients (39.4%), and in 55 of the cases, it was present at the time of evaluation. The age at the onset of SHB was reported in 55 of the cases (84.6%), and the median was 10 years (interquartile range, 7-13 years). In 30 of the patients (46.2%), SHB was evaluated as mild; in 26 (40%), as moderate; and in only 9 cases (13.9%), as severe. In the multivariable analysis for the predictor of lifetime SHB, attention-deficit/hyperactivity disorder (p = 0.016) and obsessive-compulsive disorder (OCD; p = 0.042) were determined as risk factors, while for current SHB, only tic severity (p < 0.0001) was statistically significant. When comparing predictors of SHB for children and adults, tic severity was determined as predictor for lifetime SHB in children (p < 0.0001), while the anxiety disorder was associated with lifetime SHB in adults (p = 0.05). Similarly, tic severity was a predictor of current SHB in the children group (p = 0.001), but this was not confirmed for adults. The group of patients with tic-related and non-tic-related SHB did not differ. Conclusions: Self-harm behavior appears mostly in children and adolescents and rarely begins in adulthood. Self-harm behavior is associated mainly with tic severity, obsessive-compulsive disorder, and attention-deficit/hyperactivity disorder. Clinical correlates of SHB are age related and differ at different points of life. Tic severity is the main factor associated with SHB in children. In the adult group, anxiety disorder and other psychiatric comorbidities may play the most important role.

Electrophysiological and clinical assessment of dysautonomia in multiple system atrophy (MSA) and progressive supranuclear palsy (PSP): a comparative study

CLINICAL RATIONALE FOR THE STUDY

Autonomic nervous system (ANS) involvement in different parkinsonian syndromes has been frequently discussed. It is well established in multiple system atrophy (MSA), whereas it is less evident in progressive supranuclear palsy (PSP).

AIMS OF THE STUDY

The aims were to assess the presence and pattern of ANS involvement in MSA and PSP using noninvasive tests i.e. the sympathetic skin response (SSR) test and the R-R interval variation (RRIV) test; to analyse the relationship between clinical and electrophysiological abnormalities in both disorders; and to assess whether an autonomic profile might help to differentiate them.

MATERIALS AND METHODS

Clinical and electrophysiological assessments of dysautonomia were performed in 59 patients with MSA (24 cases of MSA-C and 35 cases of MSA-P), these 59 cases including 31 females, mean disease duration 4.2 ± 2.7 years, mean age 60.3 ± 8.4 years, and in 37 patients with PSP (12 females, mean disease duration 4.6 ± 3.6 years, mean age 67.5 ± 6.1 years) and the results were compared to the results obtained from 23 healthy controls matched for age and sex.

RESULTS

Clinical dysautonomia assessed by an Autonomic Symptoms Questionnaire was observed in 97% of the MSA patients and in 84% of the PSP patients. SSR was abnormal in 64% and RRIV was abnormal in 73% of MSA cases. In PSP cases, these figures were 78% and 81% respectively. Dysautonomia was clinically more pronounced in MSA compared to PSP (p < 0.05), whereas electrophysiological testing revealed frequently subclinical ANS damage in PSP patients.

CONCLUSIONS AND CLINICAL IMPLICATIONS

Our results point to the complementary role of electrophysiological tests in the diagnostic work-up of dysautonomia in parkinsonian syndromes.

Phenomenology and Clinical Correlates of Stimulus-Bound Tics in Gilles de la Tourette Syndrome

Introduction: Stimulus-bound tics (SBTs) belong to stimulus-induced behaviors and are defined as tics that occur in response to internal or external stimuli. The aim of the study was to assess the prevalence and associations of SBTs with other stimulus-triggered behaviors, premonitory urges and stimulus sensitization in Gilles de la Tourette syndrome (GTS). Methods: We performed a prospective, one-registration study in a cohort of 140 consecutive patients with GTS. Duration of GTS was 10.6 ± 8.7 years (range: 0-39 years). SBTs were diagnosed during the interview. Results: SBTs occurred at some point in the lifetime of 20.7% of patients. The presence of SBTs in adults was four times as frequent as in children (35.5% vs. 9.0%) with the most frequent onset in adolescence (58.8%) and adulthood (29.4%). These tics started 9.1 ± 4.7 years after the onset of tics. One stimulus and mental stimulus preceded tics most frequently, 44.8 and 33.3%, respectively. There was no established pattern of tics triggered by stimuli. Multivariate logistic regression analysis showed significant associations of SBTs with age at evaluation, tic severity, and palilalia but not with any co-morbid psychiatric disorders. 80% of patients showed at least one stimulus-triggered behavior. Premonitory urges and stimulus sensitization were reported by 60.0 and 40.7% of patients, respectively. No significant correlations between SBTs, premonitory urges and stimulus sensitization were found. Conclusion: SBTs are a part of the tic spectrum and should be taken into account by clinicians who deal with GTS patients. These tics fall at the tic end of the continuum of stimulus-induced behaviors.

Serum amino acid profile in patients with Parkinson's disease

Amino acids play numerous roles in the central nervous system, serving as neurotransmitters, neuromodulators and regulators of energy metabolism. The free amino acid profile in serum of Parkinson's disease (PD) patients may be influenced by neurodegeneration, mitochondrial dysfunction, malabsorption in the gastroenteric tract and received treatment. The aim of our study was the evaluation of the profile of amino acid concentrations against disease progression. We assessed the amino acid profile in the serum of 73 patients divided into groups with early PD, late PD with dyskinesia and late PD without dyskinesia. Serum amino acid analysis was performed by high-pressure liquid chromatography with fluorescence detection. We observed some significant differences amongst the groups with respect to concentrations of alanine, arginine, phenylalanine and threonine, although no significant differences were observed between patients with advanced PD with and without dyskinesia. We conclude that this specific amino acid profile could serve as biochemical marker of PD progression.

Tetrabenazine-induced oculogyric crisis - a rare complication in the treatment of Gilles de la Tourette syndrome

Tetrabenazine is used in the treatment of chorea, tardive dyskinesia, tics, and dystonia. It rarely causes acute eyeball dystonia and the description of this complication in Gilles de la Tourette syndrome is limited. We provide a description of an acute oculogyric crisis caused by tetrabenazine in a patient with severe tics. The patient had never developed acute dystonic reactions, although he was previously exposed to numerous dopamine receptor-blocking agents. After 8 days of therapy with tetrabenazine at a dose of 62.5 mg daily, the patient developed involuntary movement of the eyeballs. Withdrawal of tetrabenazine caused resolution of all symptoms after a week. The purpose of this description is to draw attention to the potential of tetrabenazine to induce acute oculogyric crisis as well as the difficulty of differentiating drug-induced dystonia from dystonic tics in patients with Gilles de la Tourette syndrome.

Expression of RNAs Coding for Metal Transporters in Blood of Patients with Huntington's Disease

Recent studies have demonstrated elevated levels of iron (Fe) in brains of patients with Huntington's disease (HD). Striatal cells carrying mutated Huntingtin presented increased sensitivity to cadmium (Cd) toxicity, decreased sensitivity to manganese (Mn) toxicity and deficits in Mn uptake. The hypothesis arose that the observed alterations result from the altered expression and/or activity of proteins engaged in the transport of these metals, that is: transferrin (TF), transferrin receptor (TFR), divalent metal transporter 1 (DMT1) and ZIP8 protein. Here we examined the expression levels of genes encoding these proteins in blood of HD patients and control subjects. A decreasing tendency in the level of TF transcript and increasing tendency of SLC11A2 mRNA encoding DMT1 was observed in the blood of HD patients compared to the control subjects, but neither attained statistical significance. No changes were found in the levels of TFRC coding for TFR and SLC39A8 coding for ZIP8 between HD patients and controls. The results indicate that HD-associated changes in metal homeostasis occur are not related to mechanisms other than the expression level of the here analyzed metal transporters.

Association of ADORA1 rs2228079 and ADORA2A rs5751876 Polymorphisms with Gilles de la Tourette Syndrome in the Polish Population

BACKGROUND

Gilles de la Tourette syndrome (GTS) is a neurodevelopmental disorder characterized by motor and vocal tics. Hyperactivity of dopaminergic transmission is considered a prime abnormality in the pathophysiology of tics. There are reciprocal antagonistic interactions between adenosine and dopamine transmission. The aim of the study was to analyze the association of two polymorphisms, rs2228079 in ADORA1 and rs5751876 in ADORA2A, with the risk of GTS and co-morbid disorders.

MATERIAL AND METHODS

A total of 162 Polish GTS patients and 270 healthy persons were enrolled in the study. Two polymorphisms were selected on the basis of knowledge of SNPs frequencies in ADORA1 and ADORA2A. Chi-square test was used for allelic and genotypic association studies. Association of genotypes with age of tic onset was analyzed with Mann-Whitney test. Multivariate logistic regression was used to find independent predictors of GTS risk.

RESULTS

We found that the risk of GTS was associated with rs2228079 and rs5751876 polymorphisms. The GG+GT genotypes of rs2228079 in ADORA1 were underrepresented in GTS patients (p = 0.011), whereas T allele of rs5751876 in ADORA2A was overrepresented (p = 0.017). The GG genotype of rs2228079 was associated with earlier age of tic onset (p = 0.046). We found also that the minor allele G of rs2228079 was more frequent in GTS patients with depression as compared to the patients without depression (p = 0.015). Also the genotype GG was significantly more frequent in patients with obsessive compulsive disorder/behavior (OCD/OCB, p = 0.021) and depression (p = 0.032), as compared to the patients without these co-morbidities. The minor allele T frequency of rs5751876 was lower in GTS patients with co-morbid attention deficit hyperactivity disorder (p = 0.022), and TT+TC genotypes were less frequent in the non-OCD anxiety disorder group (p = 0.045).

CONCLUSION

ADORA1 and ADORA2A variants are associated with the risk of GTS, co-morbid disorders, and may affect the age of tic onset.

[Psychogenic tics: clinical characteristics and prevalence]

AIM

Clinical characteristics and the prevalence of psychogenic tics (PT) METHODS: 268 consecutively examined patients aged 4 to 54 years (221 men, 47 females; 134 children, 134 adults) with tic phenotype: Gilles de la Tourette syndrome (GTS, n = 255), chronic motor tics (n = 6), chronic vocal tics (n= 1), transient tics (n = 1), tics unclassified (n = 2), PT (n= 5) were analyzed. The diagnosis of tic disorders was made on the DSM-IV-TR criteria and mental disorders by psychiatrists.

RESULTS

PT were found in 5 patients (1.9%), aged 17 to 51 years, four men and one woman. The phenotype included vocalizations and complex movements. In none of the patients simple motor facial tics, inability to tic suppress, unchanging clinical pattern, peak severity from the beginning of the disease, lack of concern about the disease were present. The absence of premonitory urges, regression in unexpected positions, and the presence of atypical for GTS mental disorders were found in two persons. PT occurred in three persons in whom organic tics were present in childhood. Pharmacological treatment and psychotherapy were unsuccessful. In two persons spontaneous resolution occurred, in two patients the tics persist, in one person the course of PT is unknown.

CONCLUSIONS

PT are rare and may occur in patients with organic tics. The most typical features of PT are: early onset in adulthood, lack of simple motor tics, inability to tic suppress. The diagnosis is established if a few atypical symptoms for organic tics occur.

The neural correlates of specific executive dysfunctions in Parkinson's disease

Several functional neuroimaging studies in patients with Parkinson's disease (PD) have suggested that changes in the fronto-parietal-striatal networks are associated with deficits in executive functioning. However, executive functions (EF) are multifaceted and include three dissociable components: working memory, response inhibition, and task-switching. This study investigated which component of executive functioning is most strongly associated with fronto-parietal-striatal efficiency in PD. PD patients (with and without executive dysfunction), and age-matched healthy subjects, completed a battery of cognitive tests previously shown to discriminate among the three EF components. Principal component analysis conducted on the selected cognitive test variables yielded three expected EF components. The component scores were used in regression analysis to assess the relationship between the EF efficiency and blood oxygenation level-dependent (BOLD) signal related to performing the n-back, an experimental task that draws upon multiple components of executive functioning: working memory, response inhibition, and task-switching. We found distinct neural correlates of specific executive dysfunctions in patients with PD. However, all of them seem to be associated with fronto-parietal-striatal efficiency.

The BTBD9 gene polymorphisms in Polish patients with Gilles de la Tourette syndrome

Gilles de la Tourette syndrome (GTS) is a neurodevelopmental disorder characterized by motor and vocal tics. The etiology of the disorder is unknown, although the predominant role of genetic factors has been established. Variants of the BTBD9 gene (rs4714156, rs9296249 and rs9357271) have been reported to be associated with GTS in French Canadian and Chinese Han populations. Therefore, we decided to test the association between GTS and polymorphisms of the BTBD9 gene in Polish patients. Our cohort of GTS cases comprised 162 patients aged 4-54 years (mean age: 19.9 ± 8.7 years; 131 males, 80.9 percent). The control group consisted of 180 healthy persons aged 14-55 years (mean age: 23.1 ± 2.1 years; 149 males, 82.8 percent). The rs4714156, rs9296249 and rs9357271 variants of the BTBD9 gene were genotyped. No significant differences were found in minor allele frequencies (MAFs) of the SNPs tested between the two groups. The frequency of MAFs of the genotyped SNPs was lower in GTS patients with Attention Deficit Hyperactivity Disorder (for rs9357271 and rs9296249, P=0.039 and rs4714156, P=0.040) and higher in GTS patients without comorbidities (for rs9357271 and rs9296249 P=0.021 and rs4714156 P=0.025). There was a trend toward an association between the minor allele of the SNPs and mild tics (P=0.089 for rs9357271 and rs9296249, P=0.057 for rs4714156). Despite limitations of the study, including the small number of cases and analyzed SNPs, our results suggest that the examined BTBD9 variants are not associated with GTS risk, but may be associated with comorbidity and tic severity in the Polish population.

Novel A18T and pA29S substitutions in α-synuclein may be associated with sporadic Parkinson's disease

OBJECTIVE

Mutations in the α-synuclein-encoding gene SNCA are considered as a rare cause of Parkinson's disease (PD). Our objective was to examine the frequency of the SNCA point mutations among PD patients of Polish origin.

METHODS

Detection of the known SNCA point mutations A30P (c.88G>C), E46K (c.136G>A) and A53T (c.157A>T) was performed either using the Sequenom MassArray iPLEX platform or by direct sequencing of the SNCA exons 2 and 3. As the two novel substitutions A18T (c.52G>A) and A29S (c.85G>T) were identified, their frequency in a control population of Polish origin was assessed and in silico analysis performed to investigate the potential impact on protein structure and function.

RESULTS

We did not observe the previously reported point mutations in the SNCA gene in our 629 PD patients; however, two novel potentially pathogenic substitutions A18T and A29S were identified. Each variant was observed in a single patient presenting with a typical late-onset sporadic PD phenotype. Although neither variant was observed in control subjects and in silico protein analysis predicts a damaging effect for A18T and pA29S substitutions, the lack of family history brings into question the true pathogenicity of these rare variants.

CONCLUSIONS

Larger population based studies are needed to determine the pathogenicity of the A18T and A29S substitutions. Our findings highlight the possible role of rare variants contributing to disease risk and may support further screening of the SNCA gene in sporadic PD patients from different populations.

[Searching for Tourette's syndrome gene. Part 1. Heterogeneity of clinical phenotypes]

The French neuropsychiatrist Georges Gilles de la Tourette described in 1885 the "Maladie des Tics" which later was named after him, as Gilles de la Tourette syndrome (GTS). Gilles de la Tourette syndrome is a neurodevelopmental disorder characterized by simple and complex motor and vocal tics with multiple neuropsychiatric comorbidities. GTS is often concurrent with obsessive-compulsive disorder (OCD) and attention deficit hyperactivity disorder (ADHD). There are several clinical GTS subtypes: GTS only, GTS+OCD, and GTS+OCD+ADHD. Additional clinical aspects of the disorder include occurrence of anger episodes, anxiety and mood disorders, and learning and sleeping disturbances. The genetics of GTS is complex and remains unclear. So far, no causative candidate genes have been identified. However, segregation studies in families and twins with GTS provide strong evidence for the existence of a genetic background associated with a multifactorial mode of inheritance. Progress in studies on genome variability among patients with GTS is necessary to improve pharmacotherapeutic strategies of the disorder.

[Searching for Tourette's syndrome gene. Part 2. Patient's genome variability]

Gilles de la Tourette syndrome (GTS) is a complex, heterozygous genetic disorder. Twenty chromosomal rearrangements (7q22-q31, 8q13-q22, and 18q22) indicating genomic regions which may be involved in the etiology of the disorder have been reported in families with GTS. Moreover, pathogenic mutations responsible for GTS were found in the SLITRK1 and the L-histidine decarboxylase (HDC) genes. The W317X mutation in the HDC gene points to a possible role for histaminergic neurotransmission in the mechanism and modulation of tic disorder. The distribution of single nucleotide polymorphisms (SNPs) was examined in at least 14 candidate genes (DRD1, DRD2, DRD3, DRD4, DAT1, MAOA, 5HTR2A, 5HTR3A, TDO2, CNR1, HLA-DRB, IL1RA, MOG, and SGCE) using a case-control genetic association analysis. Still, a lack of replicated and consistent results was observed. Recently, rare structural variants of different genes involved in neurodevelopment determined by recurrent exonic copy number variations (CNVs) have been found in a subset of patients suffering from GTS.

Mouse sarcoma L1 cell line holoclones have a stemness signature

Accumulating data suggest that cancers contain a fraction of cells called cancer stem cells (CSCs), that may be responsible for upkeep and relapses of disease. In experimental settings, CSCs are regarded as most effective at tumour initiation in in vivo assays. Since the first isolation of cancer stem cells from acute myeloid leukaemia in 1994, cancer stem cells have been identified in human solid tumours and they have also been found in the established cell lines, based on ability of CSCs to form in vitro colonies of a specific morphology, called holoclones. Our study examined the ability of a mouse sarcoma cell line, derived from a lung metastasis of a BALB/c mouse and established as a stably growing line (L1), to produce holoclones in vitro. We aimed to verify a stemness signature of the holoclone cells. The L1 cell line was found to form holoclone colonies in vitro, which were shown to contain a percentage of CSC-like cells. A fraction of the L1 cells was able to repopulate the original cell line, and presented an increased clonogenic and metastatic potential (18th passage). In addition, MTT assay and flow cytometry of the side population fraction revealed that these cells were more resistant to chemotherapeutic drugs than the original cell line, and over-expressed the anti-apoptotic genes, GRP78 and GADD153. We conclude that mouse L1 sarcoma cell line contains CSC-like cells.

Erythropoietin concentration in serum and cerebrospinal fluid of patients with amyotrophic lateral sclerosis

Erythropoietin (EPO) acts as a neuroprotective factor and is upregulated after neuronal injury. It has been reported that in cerebrospinal fluid (CSF) of amyotrophic lateral sclerosis (ALS) patients, the EPO concentration is decreased. In this study, EPO levels in serum and CSF of 30 patients with ALS and in 15 controls, using an ELISA technique, were estimated. EPO level in serum was decreased, especially in patients with bulbar onset ALS. A trend toward a progressive EPO decline with the duration of the disease in the mild + moderate ALS cases was observed. In severe cases, a tendency towards a positive correlation of EPO and duration of the disease was present. Serum EPO values were age related only in mild + moderate ALS in patients below 40 years of age. In CSF, the EPO levels were significantly decreased. Lower EPO values in the bulbar onset ALS when compared with the spinal onset ALS were present. The EPO decrease did not correlate with the severity and duration of the disease. Age relation of the EPO level only in the mild + moderate ALS cases more than 40 years was present. Lack of differences in EPO levels between patients with ALS of rapid and slow progression indicates that EPO concentration cannot be used as a prognostic factor. Nevertheless, the decreased serum and CSF EPO concentration and the known EPO neuroprotective action may indicate that EPO administration can be a new promising therapeutic approach in ALS.

Evaluation of matrix metalloproteinases in serum of patients with amyotrophic lateral sclerosis with pattern recognition methods

Matrix metalloproteinases (MMPs) are zinc-dependent endopeptidases, which are present in central and peripheral nervous system. They are considered to be involved in the pathogenesis of several neurological diseases, as multiple sclerosis, Alzheimer disease, and amyotrophic lateral sclerosis (ALS). The aim of the present study was to evaluate the application of the pattern recognition methods for the assessment of MMPs in serum of patients with ALS. Thirty patients with amyotrophic lateral sclerosis (ALS), in two subgroups: (i) with mild and (ii) severe progressing ALS, and 15 control healthy subjects were studied. The metalloproteinases MT-MMP-1, MMP-2, MMP-9 were examined. Additional variables (age of subjects and disease duration) were also analyzed by using a standard, parallel and hierarchical classifiers. Our results indicate that: (i) MMP-2 in serum may be an important marker for the evaluation of ALS progress; (ii) the set of two features {MT-MMP-1, MMP-9} may be helpful in differentiation between ALS and healthy subjects; (iii) the error rates obtained for the pair-wise linear classifier were similar to those received for the classifiers (standard, parallel, and hierarchical) based on k-NN rule. We conclude that the pattern recognition methods may be useful for the evaluation of significance MMPs as markers in neurodegenerative diseases, such as ALS.

Matrix metalloproteinases and their tissue inhibitors in serum and cerebrospinal fluid of patients with amyotrophic lateral sclerosis

BACKGROUND AND PURPOSE

Matrix metalloproteinases (MMPs) are implicated in the pathogenesis of motor neuron degeneration in amyotrophic lateral sclerosis (ALS). We investigated the expression of MMPs and tissue inhibitors of matrix metalloproteinases (TIMPs) in serum and cerebrospinal fluid (CSF) correlating the results with age, disease duration and the clinical course.

METHODS

The material consisted of 30 ALS patients and 15 age-matched healthy controls. ELISA method to determine the expression of MT-MMP-1, MMP-2, MMP-9, TIMP-1 and TIMP-2 in serum and CSF was used. MMP-2 and MMP-9 by zymography was also tested.

RESULTS

In serum MT-MMP-1, MMP-2, MMP-9 and TIMP-1 expression was increased, especially in mild ALS cases. TIMP-2 values were normal. In CSF MT-MMP-1, MMP-2 and TIMP-1 level was either increased or normal, that of MMP-9 was decreased. TIMP-2 did not change. No correlation of MMPs and TIMP-1 expression in serum and CSF and the age of the patients was found. A correlation was observed between MMPs and TIMPs and disease duration.

CONCLUSIONS

Increased level of MMPs and TIMP-1 of ALS patients may reflect the degeneration process of motor neurons and skeletal muscles and/or is associated with tissues remodeling. The low level of MMP-9 in CSF may result from impaired balance between MMP-9 and TIMP-1 and/or its increased intrathecal degradation and physical clearance. Although the role of changed MMPs/TIMPs level in the pathogenesis of ALS is not clear their analysis in serum may be used as prognostic factor and a potential marker for monitoring treatment effects.

Coprophenomena in Tourette syndrome

The aims of this descriptive study were to examine the prevalence and associations of coprophenomena (involuntary expression of socially unacceptable words or gestures) in individuals with Tourette syndrome. Participant data were obtained from the Tourette Syndrome International Database Consortium. A specialized data collection form was completed for each of a subset of 597 consecutive new patients with Tourette syndrome from 15 sites in seven countries. Coprolalia occurred at some point in the lifetime of 19.3% of males and 14.6% of females, and copropraxia in 5.9% of males and 4.9% of females. Coprolalia was three times as frequent as copropraxia, with a mean onset of each at about 11 years, 5 years after the onset of tics. In 11% of those with coprolalia and 12% of those with copropraxia these coprophenomena were one of the initial symptoms of Tourette syndrome. The onsets of tics, coprophenomena, smelling of non-food objects, and spitting were strongly intercorrelated. Early onset of coprophenomena was not associated with its longer persistence. The most robust associations of coprophenomena were with the number of non-tic repetitive behaviors, spitting, and inappropriate sexual behavior. Although coprophenomena are a frequently feared possibility in the course of Tourette syndrome, their emergence occurs in only about one in five referred patients. Because the course and actual impact of coprophenomena are variable, additional prospective research is needed to provide better counseling and prognostic information.

Nonverbal deficits in explicit and implicit memory of Parkinson's disease patients

This study examined verbal and nonverbal aspects of explicit and implicit memory in a sample of 19 Parkinson's disease (PD) patients and 21 control subjects. For implicit memory evaluation, we used a Mirror Reading (MR) task employing verbal material as well as a nonverbal Serial Reaction Time (SRT) task. For explicit memory measurement we applied a word pairs task (verbal) and pairs of a Japanese ideograms task (nonverbal). The PD patients displayed impairments in the nonverbal tasks only, namely, in the SRT task and the pairs of Japanese ideograms task. No correlation between Wisconsin Card Sorting Test (WCST) scores and the results of tasks in which PD patients displayed deficits (SRT and pairs of Japanese ideograms) were discovered. Interestingly, such a correlation was found in the case of MR and words pairs tasks, which did not distinguish PD patients from control group.