Whole-exome sequencing is a valuable diagnostic tool for inherited peripheral neuropathies: Outcomes from a cohort of 50 families.

The inherited peripheral neuropathies (IPNs) are characterized by marked clinical and genetic heterogeneity and include relatively frequent presentations such as Charcot-Marie-Tooth disease and hereditary motor neuropathy, as well as more rare conditions where peripheral neuropathy is associated with additional features. There are over 250 genes known to cause IPN-related disorders but it is estimated that in approximately 50% of affected individuals a molecular diagnosis is not achieved. In this study, we examine the diagnostic utility of whole-exome sequencing (WES) in a cohort of 50 families with 1 or more affected individuals with a molecularly undiagnosed IPN with or without additional features. Pathogenic or likely pathogenic variants in genes known to cause IPN were identified in 24% (12/50) of the families. A further 22% (11/50) of families carried sequence variants in IPN genes in which the significance remains unclear. An additional 12% (6/50) of families had variants in novel IPN candidate genes, 3 of which have been published thus far as novel discoveries (KIF1A, TBCK, and MCM3AP). This study highlights the use of WES in the molecular diagnostic approach of highly heterogeneous disorders, such as IPNs, places it in context of other published neuropathy cohorts, while further highlighting associated benefits for discovery.

Utility of whole-exome sequencing for those near the end of the diagnostic odyssey: time to address gaps in care.

An accurate diagnosis is an integral component of patient care for children with rare genetic disease. Recent advances in sequencing, in particular whole-exome sequencing (WES), are identifying the genetic basis of disease for 25-40% of patients. The diagnostic rate is probably influenced by when in the diagnostic process WES is used. The Finding Of Rare Disease GEnes (FORGE) Canada project was a nation-wide effort to identify mutations for childhood-onset disorders using WES. Most children enrolled in the FORGE project were toward the end of the diagnostic odyssey. The two primary outcomes of FORGE were novel gene discovery and the identification of mutations in genes known to cause disease. In the latter instance, WES identified mutations in known disease genes for 105 of 362 families studied (29%), thereby informing the impact of WES in the setting of the diagnostic odyssey. Our analysis of this dataset showed that these known disease genes were not identified prior to WES enrollment for two key reasons: genetic heterogeneity associated with a clinical diagnosis and atypical presentation of known, clinically recognized diseases. What is becoming increasingly clear is that WES will be paradigm altering for patients and families with rare genetic diseases.

Whole-exome sequencing broadens the phenotypic spectrum of rare pediatric epilepsy: a retrospective study.

Whole-exome sequencing (WES) has transformed our ability to detect mutations causing rare diseases. FORGE (Finding Of Rare disease GEnes) and Care4Rare Canada are nation-wide projects focused on identifying disease genes using WES and translating this technology to patient care. Rare forms of epilepsy are well-suited for WES and we retrospectively selected FORGE and Care4Rare families with clinical descriptions that included childhood-onset epilepsy or seizures not part of a recognizable syndrome or an early-onset encephalopathy where standard-of-care investigations were unrevealing. Nine families met these criteria and a diagnosis was made in seven, and potentially eight, of the families. In the eight families we identified mutations in genes associated with known neurological and epilepsy disorders: ASAH1, FOLR1, GRIN2A (two families), SCN8A, SYNGAP1 and SYNJ1. A novel and rare mutation was identified in KCNQ2 and was likely responsible for the benign seizures segregating in the family though additional evidence would be required to be definitive. In retrospect, the clinical presentation of four of the patients was considered atypical, thereby broadening the phenotypic spectrum of these conditions. Given the extensive clinical and genetic heterogeneity associated with epilepsy, our findings suggest that WES may be considered when a specific gene is not immediately suspected as causal.

Autosomal recessive hereditary spastic paraplegia-clinical and genetic characteristics of a well-defined cohort.

We describe the clinical and genetic features of a well-characterized cohort of patients with autosomal recessive hereditary spastic paraplegia (ARHSP) in the province of Ontario. Patients with documented corticospinal tract abnormalities were screened by whole gene sequencing and multiplex ligation probe amplification for mutations in nine genes known to cause ARHSP. Of a cohort of 39 patients, a genetic diagnosis was established in 17 (44 %) and heterozygous mutations were detected in 8 (21 %). Mutations were most frequent in SPG7 (12 patients), followed by SPG11 (10 patients), PNPLA6 (SPG39, 2 patients), and ZFYVE26 (SPG15, 2 patients). Although there are associations between some clinical manifestations of ARHSP and specific genes, many patients are tested at an early stage of the disease when phenotype/genotype correlations are not obvious. Accurate molecular characterization of well-phenotyped cohorts of patients will be essential to establishing the natural history of these rare degenerative disorders to enable future clinical trials.

Acute high-intensity interval exercise reduces the postprandial glucose response and prevalence of hyperglycaemia in patients with type 2 diabetes.

High-volume endurance exercise (END) improves glycaemic control in type 2 diabetes (T2D) but many individuals cite 'lack of time' as a barrier to regular participation. High-intensity interval training (HIT) is a time-efficient method to induce physiological adaptations similar to END, but little is known regarding the effect of HIT in T2D. Using continuous glucose monitoring (CGM), we examined the 24-h blood glucose response to one session of HIT consisting of 10 × 60 s cycling efforts at ~90% maximal heart rate, interspersed with 60 s rest. Seven adults with T2D underwent CGM for 24-h on two occasions under standard dietary conditions: following acute HIT and on a non-exercise control day (CTL). HIT reduced hyperglycaemia measured as proportion of time spent above 10 mmol/l (HIT: 4.5 ± 4.4 vs. CTL: 15.2 ± 12.3%, p = 0.04). Postprandial hyperglycaemia, measured as the sum of post-meal areas under the glucose curve, was also lower after HIT vs. CTL (728 ± 331 vs. 1142 ± 556 mmol/l·9 h, p = 0.01). These findings highlight the potential for HIT to improve glycaemic control in T2D.

Natural disease course and genotype-phenotype correlations in Complex I deficiency caused by nuclear gene defects: what we learned from 130 cases.

Mitochondrial complex I is the largest multi-protein enzyme complex of the oxidative phosphorylation system. Seven subunits of this complex are encoded by the mitochondrial and the remainder by the nuclear genome. We review the natural disease course and signs and symptoms of 130 patients (four new cases and 126 from literature) with mutations in nuclear genes encoding structural complex I proteins or those involved in its assembly. Complex I deficiency caused by a nuclear gene defect is usually a non-dysmorphic syndrome, characterized by severe multi-system organ involvement and a poor prognosis. Age at presentation may vary, but is generally within the first year of life. The most prevalent symptoms include hypotonia, nystagmus, respiratory abnormalities, pyramidal signs, dystonia, psychomotor retardation or regression, failure to thrive, and feeding problems. Characteristic symptoms include brainstem involvement, optic atrophy and Leigh syndrome on MRI, either or not in combination with internal organ involvement and lactic acidemia. Virtually all children ultimately develop Leigh syndrome or leukoencephalopathy. Twenty-five percent of the patients died before the age of six months, more than half before the age of two and 75 % before the age of ten years. Some patients showed recovery of certain skills or are still alive in their thirties . No clinical, biochemical, or genetic parameters indicating longer survival were found. No clear genotype-phenotype correlations were observed, however defects in some genes seem to be associated with a better or poorer prognosis, cardiomyopathy, Leigh syndrome or brainstem lesions.

Resistance exercise enhances myofibrillar protein synthesis with graded intakes of whey protein in older men.

Feeding stimulates robust increases in muscle protein synthesis (MPS); however, ageing may alter the anabolic response to protein ingestion and the subsequent aminoacidaemia. With this as background, we aimed to determine in the present study the dose-response of MPS with the ingestion of isolated whey protein, with and without prior resistance exercise, in the elderly. For the purpose of this study, thirty-seven elderly men (age 71 (sd 4) years) completed a bout of unilateral leg-based resistance exercise before ingesting 0, 10, 20 or 40 g of whey protein isolate (W0-W40, respectively). Infusion of l-[1-13C]leucine and l-[ring-13C6]phenylalanine with bilateral vastus lateralis muscle biopsies were used to ascertain whole-body leucine oxidation and 4 h post-protein consumption of MPS in the fed-state of non-exercised and exercised leg muscles. It was determined that whole-body leucine oxidation increased in a stepwise, dose-dependent manner. MPS increased above basal, fasting values by approximately 65 and 90 % for W20 and W40, respectively (P < 0·05), but not with lower doses of whey. While resistance exercise was generally effective at stimulating MPS, W20 and W40 ingestion post-exercise increased MPS above W0 and W10 exercised values (P < 0·05) and W40 was greater than W20 (P < 0·05). Based on the study, the following conclusions were drawn. At rest, the optimal whey protein dose for non-frail older adults to consume, to increase myofibrillar MPS above fasting rates, was 20 g. Resistance exercise increases MPS in the elderly at all protein doses, but to a greater extent with 40 g of whey ingestion. These data suggest that, in contrast to younger adults, in whom post-exercise rates of MPS are saturated with 20 g of protein, exercised muscles of older adults respond to higher protein doses.

Oxidative stress, inflammation, and muscle soreness in an 894-km relay trail run.

We describe the effects of multi-day relay trail running on muscle soreness and damage, and systemic immune, inflammatory, and oxidative responses. 16 male and 4 female athletes ran 894 km in 47 stages over 95 h, with mean (SD) 6.4 (1.0) stages per athlete and 19.0 (1.7) km per stage. We observed post-pre run increases in serum creatine kinase (qualified effect size extremely large, p = 0.002), IL-6 (extremely large, p < 0.001), urinary 8-isoprostane/creatinine (extremely large, p = 0.04), TNF-α (large, p = 0.002), leukocyte count (very large, p < 0.0001) and neutrophil fraction (very large, p < 0.001); and reductions in hemoglobin (moderate, p < 0.001), hematocrit (moderate, p < 0.001), and lymphocyte fraction (trivial, p < 0.001). An increase in ORAC total antioxidant capacity (TAC, small, p = 0.3) and decrease in urinary 8-OHdG/creatinine (small, p = 0.1) were not statistically significant. During the run, muscle soreness was most frequent in the quadriceps. The threshold for muscle pain (pain-pressure algometry) in the vastus lateralis and gastrocnemius was lower post-run (small, p = 0.04 and 0.03). Average running speed was correlated with algometer pain and leukocyte count (large, r = 0.52), and TAC was correlated with IL-6 (very large, r = 0.76) and 8-isoprostane/creatinine (very large, r = -0.72). Multi-day stage-racing increases inflammation, lipid peroxidation, muscle damage and soreness without oxidative DNA damage. High TAC is associated with reduced exercise-induced lipid peroxidation, but is not related to immune response or muscle damage.

Six novel mutations in the myophosphorylase gene in patients with McArdle disease and a family with pseudo-dominant inheritance pattern.

McArdle disease is an autosomal recessive glycogenosis due to deficiency of the enzyme myophosphorylase. It results from homozygous or compound heterozygous mutations in the gene for this enzyme, PYGM. We report six novel mutations in the PYGM gene based upon sequencing data including three missense mutations (p.D51G, p.P398L, and p.N648Y), one nonsense mutation (p.Y75X), one frame-shift mutation (p.Y114SfsX181), and one amino acid deletion (p.Y53del) in six patients with McArdle disease. We also report on a Caucasian family that appeared to transmit McArdle disease in an autosomal dominant manner. In order to evaluate the potential pathogenicity of the sequence variants, we performed in silico analysis using PolyPhen-2 and SIFT BLink, along with species conservation analysis using UCSC Genome Browser. The above mutations were all predicted to be disease associated with high probability and with at least the same level of certainty as several confirmed mutations. The current data add to the list of pathogenic mutations in the PYGM gene associated with McArdle disease.

Creatine as a therapeutic strategy for myopathies.

Myopathies are genetic or acquired disorders of skeletal muscle that lead to varying degrees of weakness, atrophy, and exercise intolerance. In theory, creatine supplementation could have a number of beneficial effects that could enhance function in myopathy patients, including muscle mass, strength and endurance enhancement, lower calcium levels, anti-oxidant effects, and reduced apoptosis. Patients with muscular dystrophy respond to several months of creatine monohydrate supplementation (~0.075-0.1 g/kg/day) with greater strength (~9%) and fat-free mass (~0.63 kg). Patients with myotonic dystrophy do not show as consistent an effect, possibly due to creatine transport issues. Creatine monohydrate supplementation shows modest benefits only at lower doses and possibly negative effects (cramping) at higher doses in McArdle's disease patients. Patients with MELAS syndrome show some evidence of benefit from creatine supplementation in exercise capacity, with the effects in patients with CPEO being less robust, again, possibly due to limited muscle creatine uptake. The evidence for side effects or negative impact upon serological metrics from creatine supplementation in all groups of myopathy patients is almost non-existent and pale in comparison to the very substantial and well-known side effects from our current chemotherapeutic interventions for some myopathies (i.e., corticosteroids).

Stress in Parents of Children With Genetically Determined Leukoencephalopathies: A Pilot Study.

Genetically determined leukoencephalopathies comprise a group of rare inherited white matter disorders. The majority are progressive diseases resulting in early death. We performed a cross-sectional pilot study including 55 parents from 36 families to assess the level of stress experienced by parents of patients with genetically determined leukoencephalopathies, aged 1 month to 12 years. Thirty-four mothers and 21 fathers completed the Parenting Stress Index-4th Edition. One demographic questionnaire was completed per family. Detailed clinical data was gathered on all patients. Statistical analysis was performed with total stress percentile score as the primary outcome. Mothers and fathers had significantly higher stress levels compared with the normative sample; 20% of parents had high levels of stress whereas 11% had clinically significant levels of stress. Mothers and fathers had comparable total stress percentile scores. We identified pediatric behavioral difficulties and gross motor function to be factors influencing stress in mothers. Our study is the first to examine parental stress in this population and highlights the need for parental support early in the disease course. In this pilot study, we demonstrated that using the Parenting Stress Index-4th Edition to assess stress levels in parents of patients with genetically determined leukoencephalopathies is feasible, leads to valuable and actionable results, and should be used in larger, prospective studies.

Intracerebral periventricular pseudocysts in a fetus with mitochondrial depletion syndrome: an association or coincidence.

We report the prenatal ultrasound and magnetic resonance imaging finding of periventricular, large subependymal pseudocysts (SEPCs) in a patient who was later diagnosed as having mitochondrial depletion syndrome (MDS). To our knowledge, this is the first report of fetal SEPCs in a patient with MDS. These findings may provide an important diagnostic tool for prenatal diagnosis of MDS in at risk pregnancies when the gene mutation causing the condition has not been delineated. It may also direct the neonatologist in the postnatal care of the newborn detected prenatally with SEPCs in view of the association of this finding with infection, chromosome abnormalities, metabolic disorders and other abnormalities, when such findings are identified serendipitously. Further research is needed to find if the SEPCs detected in our patient is an association or a coincidental finding.

Novel heterozygous mutations in the PGAM2 gene with negative exercise testing.

Pathogenic variants in the PGAM2 gene are associated with glycogen storage disease type X (GSDX) and is characterized by exercise induced muscle cramping, weakness, myoglobinuria, and often tubular aggregates in skeletal muscle. We report here a patient diagnosed with GSDX at 52 years of age with a normal increase in post-exercise lactate with both anaerobic and aerobic exercise. Genetic testing found two novel PGAM2 variants (c.426C > A, p.Tyr142Ter and c.533delG, p.Gly178Alafs*31).

Creatine for treating muscle disorders.

BACKGROUND: Progressive muscle weakness is a main symptom of most hereditary muscle diseases. Creatine is a popular nutritional supplement among athletes. It improves muscle performance in healthy individuals and might be helpful for treating myopathies. OBJECTIVES: To evaluate the efficacy of oral creatine supplementation in muscle diseases. SEARCH STRATEGY: We searched the Cochrane Neuromuscular Disease Group Register in May 2004 for randomised trials using the search term 'creatine'. We also searched the Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 2, 2005) using the same search term. We adapted this strategy to search MEDLINE (PubMed, from January 1966 to September 2005) and EMBASE (from January 1980 to May 2004). We reviewed the bibliographies of the randomised trials identified, contacted the authors and known experts in the field and approached pharmaceutical companies to identify additional published or unpublished data. SELECTION CRITERIA: Types of studies: randomised or quasi-randomised controlled trials. TYPES OF PARTICIPANTS: people of all ages with hereditary muscle disease. Types of intervention: any creatine supplementation of at least 0.03 g/kg body weight/day. PRIMARY OUTCOME MEASURE: change in muscle strength measured by quantitative muscle testing. SECONDARY OUTCOME MEASURES: change in muscle strength measured by manual muscle testing, change in energy parameters assessed by 31 phosphorous spectroscopy, change in muscle mass or a surrogate for muscle mass, adverse events. DATA COLLECTION AND ANALYSIS: Two authors independently applied the selection criteria, assessed trial quality and extracted data. Some missing data were obtained from investigators. MAIN RESULTS: Twelve trials, including 266 participants, met the selection criteria. One trial compared creatine and glutamine treatment with placebo. In trials with 138 participants with muscular dystrophies treated with creatine, there was a significant increase in maximum voluntary contraction in the creatine group compared to placebo, with a weighted mean difference of 8.47% (95% confidence intervals 3.55 to 13.38). There was also an increase in lean body mass during creatine treatment compared to placebo (weighted mean difference 0.63 kg, 95% confidence intervals 0.02 to 1.25). No trial reported any clinically relevant adverse event. In trials with 33 participants with metabolic myopathies treated with creatine, there was no significant difference in maximum voluntary contraction between the creatine and placebo group (weighted mean difference -2.26%, confidence intervals -6.29 to 1.78). One trial reported a significant increase in muscle pain during high-dose creatine treatment (150 mg/kg body weight) in glycogen storage disease type V. AUTHORS' CONCLUSIONS: Evidence from randomised controlled trials shows that short- and medium-term creatine treatment improves muscle strength in people with muscular dystrophies, and is well-tolerated. Evidence from randomised controlled trials does not show significant improvement in muscle strength in metabolic myopathies. High-dose creatine in glycogenosis type V increased muscle pain.

Analysis of global mRNA expression in human skeletal muscle during recovery from endurance exercise.

To search for novel transcriptional pathways that are activated in skeletal muscle after endurance exercise, we used cDNA microarrays to measure global mRNA expression after an exhaustive bout of high-intensity cycling (approximately 75 min). Healthy, young, sedentary males performed the cycling bout, and skeletal muscle biopsies were taken from the vastus lateralis before, and at 3 and 48 h after exercise. We examined mRNA expression in individual muscle samples from four subjects using cDNA microarrays, used repeated-measures significance analysis of microarray (SAM) to determine statistically significant expression changes, and confirmed selected results using real-time RT-PCR. In total, the expression of 118 genes significantly increased 3 h postcycling and 8 decreased. At 48 h, the expression of 29 genes significantly increased and 5 decreased. Many of these are potentially important novel genes involved in exercise recovery and adaptation, including several involved in 1) metabolism and mitochondrial biogenesis (FOXO1, PPARdelta, PPARgamma, nuclear receptor binding protein 2, IL-6 receptor, ribosomal protein L2, aminolevulinate delta-synthase 2); 2) the oxidant stress response (metalothioneins 1B, 1F, 1G, 1H, 1L, 2A, 3, interferon regulatory factor 1); and 3) electrolyte transport across membranes [Na+-K+-ATPase (beta3), SERCA3, chloride channel 4]. Others include genes involved in cell stress, proteolysis, apoptosis, growth, differentiation, and transcriptional activation, as well as all three nuclear receptor subfamily 4A family members (Nur77, Nurr1, and Nor1). This study is the first to characterize global mRNA expression during recovery from endurance exercise, and the results provide potential insight into 1) the transcriptional contributions to homeostatic recovery in human skeletal muscle after endurance exercise, and 2) the transcriptional contributions from a single bout of endurance exercise to the adaptive processes that occur after a period of endurance exercise training.

Proximal myopathy with focal depletion of mitochondria and megaconial congenital muscular dystrophy are allelic conditions caused by mutations in CHKB.

We recently evaluated two of the original three patients (siblings) diagnosed with Proximal Myopathy with Focal Depletion of Mitochondria. The condition was named for the distinctive pattern of enlarged mitochondria around the periphery of muscle fibres with a complete absence in the middle. These siblings, aged 37 and 40, are cognitively normal with mild non-progressive muscle weakness and a susceptibility to rhabdomyolysis. Both were shown to be compound heterozygotes for novel mutations (c.263C>T + c.950T>A) in CHKB, the gene currently associated with Megaconial Congenital Muscular Dystrophy. Individuals with this condition have early-onset muscle weakness and profound intellectual disability but share the same unique pattern on muscle biopsy as was noted in Proximal Myopathy with Focal Depletion of Mitochondria; focal depletion of mitochondria was surrounded by abnormally large "megaconial" mitochondria. Thus the phenotypic spectrum of CHKB mutations ranges from a congenital muscular dystrophy with intellectual disability to a later-onset non-progressive muscular weakness with normal cognition.

Alpha-sarcoglycanopathy presenting as exercise intolerance and rhabdomyolysis in two adults.

Two patients with exercise-induced myalgias and rhabdomyolysis with myoglobinuria were evaluated with muscle biopsy and comprehensive myopathy next generation sequencing (NGS) gene panels. Genetic analysis revealed homozygosity for two known pathogenic SGCA mutations (R284C in Patient 1 and V247M in Patient 2). Muscle biopsy showed minimal changes with normal immunohistochemistry for α-sarcoglycan. Western blotting showed 27% and 35% of normal α-sarcoglycan immunoreactivity when compared to age matched controls, confirming the diagnosis of α-sarcoglycanopathy in both patients. The sarcoglycan genes should be added to the differential diagnosis for cases that present with rhabdomyolysis, exercise intolerance, and hyperCKemia, even in the absence of muscle weakness or normal α-sarcoglycan immunohistochemistry. Work-up of patients with these types of non-specific presentation may be best facilitated through the use of non-specific NGS myopathy panels.

Combined aerobic exercise and enzyme replacement therapy rejuvenates the mitochondrial-lysosomal axis and alleviates autophagic blockage in Pompe disease.

A unifying feature in the pathogenesis of aging, neurodegenerative disease, and lysosomal storage disorders is the progressive deposition of macromolecular debris impervious to enzyme catalysis by cellular waste disposal mechanisms (e.g., lipofuscin). Aerobic exercise training (AET) has pleiotropic effects and stimulates mitochondrial biogenesis, antioxidant defense systems, and autophagic flux in multiple organs and tissues. Our aim was to explore the therapeutic potential of AET as an ancillary therapy to mitigate autophagic buildup and oxidative damage and rejuvenate the mitochondrial-lysosomal axis in Pompe disease (GSD II/PD). Fourteen weeks of combined recombinant acid α-glucosidase (rhGAA) and AET polytherapy attenuated mitochondrial swelling, fortified antioxidant defense systems, reduced oxidative damage, and augmented glycogen clearance and removal of autophagic debris/lipofuscin in fast-twitch skeletal muscle of GAA-KO mice. Ancillary AET potently augmented the pool of PI4KA transcripts and exerted a mild restorative effect on Syt VII and VAMP-5/myobrevin, collectively suggesting improved endosomal transport and Ca(2+)- mediated lysosomal exocytosis. Compared with traditional rhGAA monotherapy, AET and rhGAA polytherapy effectively mitigated buildup of protein carbonyls, autophagic debris/lipofuscin, and P62/SQSTM1, while enhancing MnSOD expression, nuclear translocation of Nrf-2, muscle mass, and motor function in GAA-KO mice. Combined AET and rhGAA therapy reactivates cellular clearance pathways, mitigates mitochondrial senescence, and strengthens antioxidant defense systems in GSD II/PD. Aerobic exercise training (or pharmacologic targeting of contractile-activity-induced pathways) may have therapeutic potential for mitochondrial-lysosomal axis rejuvenation in lysosomal storage disorders and related conditions (e.g., aging and neurodegenerative disease).

Creatine monohydrate increases strength in patients with neuromuscular disease.

Creatine monohydrate has been shown to increase strength in studies of young healthy subjects and in a few studies with patients. Creatine monohydrate (10 g daily for 5 days to 5 g daily for 5 days) was administered to patients with neuromuscular disease in a pilot study (Study 1; n = 81), followed by a single-blinded study (Study 2; n = 21). Body weight, handgrip, dorsiflexion, and knee extensor strength were measured before and after treatment. Creatine administration increased all measured indices in both studies. Short-term creatine monohydrate increased high-intensity strength significantly in patients with neuromuscular disease.

Monoclonal antibodies against Epstein-Barr virus cross-react with alpha-synuclein in human brain.

Using antibodies generated against the latent membrane protein 1 of Epstein-Barr virus, intense immunoreactivity of Lewy bodies (in PD and dementia with Lewy bodies) and glial cytoplasmic inclusions (in multiple system atrophy) was demonstrated. ELISA and Western blotting techniques confirmed that this immunolabeling was due to cross-reactivity of the antiviral antibody with alpha-synuclein, a neuronal protein implicated in the pathogenesis of PD. This example of cross-reactivity between Epstein-Barr virus and alpha-synuclein may bear implications for further elucidating infectious or autoimmune mechanisms in PD.