Disability progression in multiple sclerosis: a Tunisian prospective cohort study.

Data regarding multiple sclerosis (MS) course in North Africans are scarce and mainly retrospective. To prospectively assess disability progression of multiple sclerosis in Tunisia. Analysis was performed in 600 patients from the MS database of the Mongi Ben Hmida National Institute of Neurology (Tunis, Tunisia), prospectively recorded over a 10-year period. Two MS phases were defined: phase 1, from MS clinical onset to Disability Status Scale (DSS) 3; and phase 2, from DSS 3 to DSS 6. Median durations of both phases and median ages at DSS 3 and DSS 6 were estimated using the Kaplan-Meier method. Median ages at DSS scores 3 and 6 were 48 years (95% confidence interval (CI), 45-50) and 53 years (95% CI, 52-55), respectively. Median time from onset to DSS 3 (phase 1 duration) was 9 years (95% CI, 7-11) and median time to DSS 6 was 12 years (95% CI, 10-15). Median phase 2 duration was 3 years (95% CI, 2.4-3.6). Males and progressive-onset patients had faster disability worsening during the first phase of the disease. Conversely, disability progression during the second phase was independent of gender and MS phenotype at onset. Our study showed that disability progression followed a two-stage process in Tunisian MS patients with however a more aggressive course compared to that in Westerners.

SLC25A46 Mutations Associated with Autosomal Recessive Cerebellar Ataxia in North African Families.

BACKGROUND: Autosomal recessive cerebellar ataxias (ARCA) are a complex group of neurodegenerative disorders with high clinical and genetic heterogeneity. In most cases, the cerebellar ataxia is not pure, and complicating clinical features such as pyramidal signs or extraneurological features are found. OBJECTIVE: To identify the genetic origin of the cerebellar ataxia for 3 consanguineous North African families presenting with ARCA. METHODS: Genome-wide high-density SNP genotyping and whole-exome sequencing were performed followed by Sanger sequencing for mutation confirmation. RESULTS: Two variants were identified in SLC25A46. Mutations in this gene have been previously associated with Charcot-Marie-Tooth type 2 and optic atrophy. While the previously reported variant p.Arg340Cys seems to be consistently associated with the same clinical features such as childhood onset, optic atrophy, gait and speech difficulties, and wasting of the lower limbs, the patient with the novel mutation p.Trp160Ser did not present with optic atrophy and his ocular abnormalities were limited to nystagmus and saccadic pursuit. CONCLUSION: In this study, we report a novel variant (p.Trp160Ser) in SLC25A46 and we broaden the phenotypic spectrum associated with mutations in SLC25A46.

DNAJC13 mutations in Parkinson disease.

A Saskatchewan multi-incident family was clinically characterized with Parkinson disease (PD) and Lewy body pathology. PD segregates as an autosomal-dominant trait, which could not be ascribed to any known mutation. DNA from three affected members was subjected to exome sequencing. Genome alignment, variant annotation and comparative analyses were used to identify shared coding mutations. Sanger sequencing was performed within the extended family and ethnically matched controls. Subsequent genotyping was performed in a multi-ethnic case-control series consisting of 2928 patients and 2676 control subjects from Canada, Norway, Taiwan, Tunisia, and the USA. A novel mutation in receptor-mediated endocytosis 8/RME-8 (DNAJC13 p.Asn855Ser) was found to segregate with disease. Screening of cases and controls identified four additional patients with the mutation, of which two had familial parkinsonism. All carriers shared an ancestral DNAJC13 p.Asn855Ser haplotype and claimed Dutch-German-Russian Mennonite heritage. DNAJC13 regulates the dynamics of clathrin coats on early endosomes. Cellular analysis shows that the mutation confers a toxic gain-of-function and impairs endosomal transport. DNAJC13 immunoreactivity was also noted within Lewy body inclusions. In late-onset disease which is most reminiscent of idiopathic PD subtle deficits in endosomal receptor-sorting/recycling are highlighted by the discovery of pathogenic mutations VPS35, LRRK2 and now DNAJC13. With this latest discovery, and from a neuronal perspective, a temporal and functional ecology is emerging that connects synaptic exo- and endocytosis, vesicular trafficking, endosomal recycling and the endo-lysosomal degradative pathway. Molecular deficits in these processes are genetically linked to the phenotypic spectrum of parkinsonism associated with Lewy body pathology.

Mutations in GBA2 cause autosomal-recessive cerebellar ataxia with spasticity.

Autosomal-recessive cerebellar ataxia (ARCA) comprises a large and heterogeneous group of neurodegenerative disorders with more than 20 different forms currently recognized, many of which are also associated with increased tone and some of which have limb spasticity. Gaucher disease is a lysosomal storage disease resulting from a defect in the enzyme acid ß-glucosidase 1. ß-glucosidase 2 is an enzyme with similar glucosylceramidase activity but to date has not been associated with a monogenic disorder. We studied four unrelated consanguineous families of Tunisian decent diagnosed with cerebellar ataxia of unknown origin. We performed homozygosity mapping and whole-exome sequencing in an attempt to identify the genetic origin of their disorder. We were able to identify mutations responsible for autosomal-recessive ataxia in these families within the gene encoding ß-glucosidase 2, GBA2. Two nonsense mutations (c.363C>A [p.Tyr121(∗)] and c.1018C>T [p.Arg340(∗)]) and a substitution (c.2618G>A [p.Arg873His]) were identified, probably resulting in nonfunctional enzyme. This study suggests GBA2 mutations are a cause of recessive spastic ataxia and responsible for a form of glucosylceramide storage disease in humans.

Motor phenotype of LRRK2-associated Parkinson's disease: a Tunisian longitudinal study.

Mutations in the leucine-rich repeat kinase 2 gene (LRRK2) were found to be a significant cause of late-onset autosomal dominant forms of Parkinson's disease (PD). To determine the motor characteristics of LRRK2-related disease, we conducted a longitudinal study of 58 G2019S LRRK2-associated PD patients and compared them with genetically undefined (GU) PD patients. Fifty-eight patients diagnosed with PD-related LRRK2 G2019S mutation were included in the study and compared with 54 sporadic PD patients with negative tests for LRRK2 G2019S, PINK1, SNCA, PRKN, and DJ1 mutations. Patients were assessed at baseline and after a follow-up period of 6 years. The Movement Disorder Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS), the Hoehn and Yahr, and the Schwab and England scores were determined. Logistic regression was used to examine associations of G2019S mutation status with motor phenotype and rate of motor decline. The LRRK2-associated PD patients had a mean age of onset of 56.25 ± 12.05 years and in most cases (58.6%) a postural instability gait difficulty (PIGD) phenotype. The mean annual decline in the MDS-UDRS III motor score and the Hoehn and Yahr staging was of 1.3% and 2%, respectively. The PIGD phenotype predicted a more rapid progression of motor impairment. The PD motor phenotype and motor scores were similar in the LRRK2-associated PD group and in the GU PD group, with no significant differences in the progression rate of motor impairment. Motor phenotype seems to be similar in LRRK2-related PD and idiopathic PD.

Molecular, clinical and peripheral neuropathy study of Tunisian patients with ataxia with vitamin E deficiency.

Ataxia with vitamin E deficiency is an autosomal recessive cerebellar ataxia caused by mutations in the α-tocopherol transfer protein coding gene localized on chromosome 8q, leading to lower levels of serum vitamin E. More than 91 patients diagnosed with ataxia with vitamin E deficiency have been reported worldwide. The majority of cases originated in the Mediterranean region, and the 744delA was the most common mutation among the 22 mutants previously described. We examined the clinical and molecular features of a large cohort of 132 Tunisian patients affected with ataxia with vitamin E deficiency. Of these patients, nerve conduction studies were performed on 45, and nerve biopsy was performed on 13. Serum vitamin E was dramatically reduced for 105 of the patients analysed. Molecular analysis revealed that 91.7% of the patients (n = 121) were homozygous for the 744delA mutation. Three other mutations were detected among the remaining patients (8.3%, n = 11) in the homozygous state. Two were previously reported (400C>T and 205-1G>T), and one was novel (553+1T>A). Age of onset was 13.2 ± 5.9 years, with extremes of 2 and 37 years. All described patients exhibited persistent progressive cerebellar ataxia with generally absent tendon reflexes. Deep sensory disturbances, pyramidal syndrome and skeletal deformities were frequent. Head tremor was present in 40% of the patients. Absence of neuropathy or mild peripheral neuropathy was noted in more than half of the cohort. This is the largest study of the genetic, clinical and peripheral neuropathic characteristics in patients with ataxia and vitamin E deficiency. The 744delA mutation represents the most common pathological mutation in Tunisia and worldwide, likely because of a Mediterranean founder effect. Our study led us to suggest that any patient displaying an autosomal recessive cerebellar ataxia phenotype with absent tendon reflexes and minor nerve abnormalities should first be screened for the 744delA mutation, even in the absence of a serum vitamin E measurement.

VPS35 mutations in Parkinson disease.

The identification of genetic causes for Mendelian disorders has been based on the collection of multi-incident families, linkage analysis, and sequencing of genes in candidate intervals. This study describes the application of next-generation sequencing technologies to a Swiss kindred presenting with autosomal-dominant, late-onset Parkinson disease (PD). The family has tremor-predominant dopa-responsive parkinsonism with a mean onset of 50.6 ± 7.3 years. Exome analysis suggests that an aspartic-acid-to-asparagine mutation within vacuolar protein sorting 35 (VPS35 c.1858G>A; p.Asp620Asn) is the genetic determinant of disease. VPS35 is a central component of the retromer cargo-recognition complex, is critical for endosome-trans-golgi trafficking and membrane-protein recycling, and is evolutionarily highly conserved. VPS35 c.1858G>A was found in all affected members of the Swiss kindred and in three more families and one patient with sporadic PD, but it was not observed in 3,309 controls. Further sequencing of familial affected probands revealed only one other missense variant, VPS35 c.946C>T; (p.Pro316Ser), in a pedigree with one unaffected and two affected carriers, and thus the pathogenicity of this mutation remains uncertain. Retromer-mediated sorting and transport is best characterized for acid hydrolase receptors. However, the complex has many types of cargo and is involved in a diverse array of biologic pathways from developmental Wnt signaling to lysosome biogenesis. Our study implicates disruption of VPS35 and retromer-mediated trans-membrane protein sorting, rescue, and recycling in the neurodegenerative process leading to PD.

Translation initiator EIF4G1 mutations in familial Parkinson disease.

Genome-wide analysis of a multi-incident family with autosomal-dominant parkinsonism has implicated a locus on chromosomal region 3q26-q28. Linkage and disease segregation is explained by a missense mutation c.3614G>A (p.Arg1205His) in eukaryotic translation initiation factor 4-gamma (EIF4G1). Subsequent sequence and genotype analysis identified EIF4G1 c.1505C>T (p.Ala502Val), c.2056G>T (p.Gly686Cys), c.3490A>C (p.Ser1164Arg), c.3589C>T (p.Arg1197Trp) and c.3614G>A (p.Arg1205His) substitutions in affected subjects with familial parkinsonism and idiopathic Lewy body disease but not in control subjects. Despite different countries of origin, persons with EIF4G1 c.1505C>T (p.Ala502Val) or c.3614G>A (p.Arg1205His) mutations appear to share haplotypes consistent with ancestral founders. eIF4G1 p.Ala502Val and p.Arg1205His disrupt eIF4E or eIF3e binding, although the wild-type protein does not, and render mutant cells more vulnerable to reactive oxidative species. EIF4G1 mutations implicate mRNA translation initiation in familial parkinsonism and highlight a convergent pathway for monogenic, toxin and perhaps virally-induced Parkinson disease.

A phase I trial of adeno-associated virus serotype 1-γ-sarcoglycan gene therapy for limb girdle muscular dystrophy type 2C.

γ-Sarcoglycanopathy or limb girdle muscular dystrophy type 2C is an untreatable disease caused by autosomal recessively inherited mutations of the γ-sarcoglycan gene. Nine non-ambulatory patients (two males, seven females, mean age 27 years; range 16-38 years) with del525T homozygous mutation of the γ-sarcoglycan gene and no γ-sarcoglycan immunostaining on muscle biopsy were divided into three equal groups to receive three escalating doses of an adeno-associated virus serotype 1 vector expressing the human γ-sarcoglycan gene under the control of the desmin promoter, by local injection into the extensor carpi radialis muscle. The first group received a single injection of 3 × 10(9) viral genomes in 100 µl, the second group received a single injection of 1.5 × 10(10) viral genomes in 100 µl, and the third group received three simultaneous 100-µl injections at the same site, delivering a total dose of 4.5 × 10(10) viral genomes. No serious adverse effects occurred during 6 months of follow-up. All nine patients became adeno-associated virus serotype 1 seropositive and one developed a cytotoxic response to the adeno-associated virus serotype 1 capsid. Thirty days later, immunohistochemical analysis of injected-muscle biopsy specimens showed γ-sarcoglycan expression in all three patients who received the highest dose (4.7-10.5% positively stained fibres), while real-time polymerase chain reaction detected γ-sarcoglycan messenger RNA. In one patient, γ-sarcoglycan protein was detected by western blot. For two other patients who received the low and intermediate doses, discrete levels of γ-sarcoglycan expression (<1% positively stained fibres) were also detectable. Expression of γ-sarcoglycan protein can be induced in patients with limb girdle muscular dystrophy type 2C by adeno-associated virus serotype 1 gene transfer, with no serious adverse effects.

Ganglioside-induced differentiation-associated protein-1 is mutant in Charcot-Marie-Tooth disease type 4A/8q21.

We previously localized and fine-mapped Charcot Marie Tooth 4A (CMT4A), the autosomal recessive, demyelinating peripheral neuropathy, to chromosome 8. Through additional positional cloning, we have identified a good candidate gene, encoding ganglioside-induced differentiation-associated protein-1 (GDAP1). We found three different mutations in four different Tunisian families-two nonsense and one missense mutation. How mutations in GDAP1 lead to CMT4A remains to be understood.

Establishing an online resource to facilitate global collaboration and inclusion of underrepresented populations: Experience from the MJFF Global Genetic Parkinson's Disease Project.

Parkinson's disease (PD) is the fastest-growing neurodegenerative disorder, currently affecting ~7 million people worldwide. PD is clinically and genetically heterogeneous, with at least 10% of all cases explained by a monogenic cause or strong genetic risk factor. However, the vast majority of our present data on monogenic PD is based on the investigation of patients of European White ancestry, leaving a large knowledge gap on monogenic PD in underrepresented populations. Gene-targeted therapies are being developed at a fast pace and have started entering clinical trials. In light of these developments, building a global network of centers working on monogenic PD, fostering collaborative research, and establishing a clinical trial-ready cohort is imperative. Based on a systematic review of the English literature on monogenic PD and a successful team science approach, we have built up a network of 59 sites worldwide and have collected information on the availability of data, biomaterials, and facilities. To enable access to this resource and to foster collaboration across centers, as well as between academia and industry, we have developed an interactive map and online tool allowing for a quick overview of available resources, along with an option to filter for specific items of interest. This initiative is currently being merged with the Global Parkinson's Genetics Program (GP2), which will attract additional centers with a focus on underrepresented sites. This growing resource and tool will facilitate collaborative research and impact the development and testing of new therapies for monogenic and potentially for idiopathic PD patients.

Sequence alterations within CYP7B1 implicate defective cholesterol homeostasis in motor-neuron degeneration.

The hereditary spastic paraplegias (HSPs) are a genetically and clinically heterogeneous group of upper-motor-neuron degenerative diseases characterized by selective axonal loss in the corticospinal tracts and dorsal columns. Although numerous mechanisms involving defective subcellular transportation, mitochondrial malfunction, and increased oxidative stress have been proposed, the pathogenic basis underlying the neuronal loss is unknown. We have performed linkage analysis to refine the extent of the SPG5 disease locus and conducted sequence analysis of the genes located within this region. This identified sequence alterations in the cytochrome P450-7B1 (CYP7B1) associated with this pure form of HSP. In the liver, CYP7B1 offers an alternative pathway for cholesterol degradation and also provides the primary metabolic route for the modification of dehydroepiandrosterone neurosteroids in the brain. These findings provide the first direct evidence of a pivotal role of altered cholesterol metabolism in the pathogenesis of motor-neuron degenerative disease and identify a potential for therapeutic intervention in this form of HSP.

Inhibition of LRRK2 kinase activity leads to dephosphorylation of Ser(910)/Ser(935), disruption of 14-3-3 binding and altered cytoplasmic localization.

LRRK2 (leucine-rich repeat protein kinase 2) is mutated in a significant number of Parkinson's disease patients. Since a common mutation that replaces Gly2019 with a serine residue enhances kinase catalytic activity, small-molecule LRRK2 inhibitors might have utility in treating Parkinson's disease. However, the effectiveness of inhibitors is difficult to assess, as no physiological substrates or downstream effectors have been identified that could be exploited to develop a robust cell-based assay. We recently established that LRRK2 bound 14-3-3 protein isoforms via its phosphorylation of Ser910 and Ser935. In the present study we show that treatment of Swiss 3T3 cells or lymphoblastoid cells derived from control or a Parkinson's disease patient harbouring a homozygous LRRK2(G2019S) mutation with two structurally unrelated inhibitors of LRRK2 (H-1152 or sunitinib) induced dephosphorylation of endogenous LRRK2 at Ser910 and Ser935, thereby disrupting 14-3-3 interaction. Our results suggest that H-1152 and sunitinib induce dephosphorylation of Ser910 and Ser935 by inhibiting LRRK2 kinase activity, as these compounds failed to induce significant dephosphorylation of a drug-resistant LRRK2(A2016T) mutant. Moreover, consistent with the finding that non-14-3-3-binding mutants of LRRK2 accumulated within discrete cytoplasmic pools resembling inclusion bodies, we observed that H-1152 causes LRRK2 to accumulate within inclusion bodies. These findings indicate that dephosphorylation of Ser910/Ser935, disruption of 14-3-3 binding and/or monitoring LRRK2 cytoplasmic localization can be used as an assay to assess the relative activity of LRRK2 inhibitors in vivo. These results will aid the elaboration and evaluation of LRRK2 inhibitors. They will also stimulate further research to understand how phosphorylation of Ser910 and Ser935 is controlled by LRRK2, and establish any relationship to development of Parkinson's disease.

Spinal muscular atrophy due to double gene conversion event.

Spinal muscular atrophy (SMA) is an autosomal recessive disease characterized by degeneration of the anterior horn cells of the spinal cord. The survival motor neuron (SMN) gene has been identified as an SMA-determining gene. SMN exists as two copies in 5q13, and deletions in exons 7 and 8 of the telomeric copy (SMN(T)) occur in 95% of patients, regardless of disease severity. In a minority of patients, exon 7 but not exon 8 of SMN(T) appears deleted. We now report a patient with typical features of SMA type II who carried homozygous deletions of SMN(T) exon 7 and centromeric SMN (SMN(C)) exon 8 but retained SMN(T) exon 8 and SMN(C) exon 7. Sequence analysis demonstrated that SMN(C) exon 7 was adjacent to SMN(T) exon 8 on both SMN copies, indicating a double conversion. We confirm that sequence conversion is a common event in SMA and is associated with the milder form of the disease. The severity, however, can be modified in either positive or negative direction by other factors.

Association of BglII Polymorphism in ITGA2 and (894G/T and -786T/C) Polymorphisms in eNOS Gene With Stroke Susceptibility in Tunisian Patients α2 Gene Polymorphism in α2ß1 Integrin and eNOS Gene Variants and Stroke.

BACKGROUND: This study investigated the association of BglII polymorphism in α2ß1 integrin gene (ITGA2) and eNOS (894G/T and -786T/C) polymorphisms with ischemic stroke (IS) in Tunisian patients. METHODS: The study comprised 210 patients with IS and 208 controls. The genotypes of the BglII polymorphism in ITGA2 and eNOS (894G/T and -786T/C) polymorphisms were determined using the PCR-RFLP. The χ2 test was used and the genotype data comparison included heterozygous groups. Haplotype estimation and multiple logistic regression analysis were performed to analyze the significance of polymorphisms. RESULTS: The genotype distribution of the BglII polymorphism was significantly different between cases and controls (p < 0.004). This polymorphism was associated with the risk of IS (OR = 3.38, p < 0.001) for the BglII(+/+) genotype. Likewise, the genotype distributions of eNOS (894G/T and -786T/C) polymorphisms were significantly different between the two groups (p < 0.005 and p < 0.01, respectively). The 894G/T polymorphism increased the risk of IS for the TT genotype (OR = 2.23, p < 0.008) and the GT genotype (OR = 1.74, p < 0.009). In addition, the -786T/C variant in the eNOS gene was a risk factor for IS for CC homozygous (OR = 2.52, p < 0.005). T-C Haplotype (OR = 3.06) from combination of the eNOS (894G/T and -786T/C) and T-C-BglII(+) haplotype (OR = 2.76) from combination of eNOS and ITGA2 polymorphisms represented high risks for IS. CONCLUSIONS: This study suggests that the BglII variant in ITGA2 is associated with IS susceptibility. Furthermore, the 894G/T and -786T/C polymorphisms in the eNOS gene may be considered as genetic risk factors for IS in the Tunisian population.

A comparative study of LRRK2, PINK1 and genetically undefined familial Parkinson's disease.

Genetic classification of Parkinson's disease (PD) subtypes may become the preferred diagnostic tool for neurologists. Herein we compare clinical features from a large cohort of patients with familial PD of unknown aetiology or attributable to distinct genetic forms. Comprehensive neurological examinations were performed in 231 familial PD patients from Tunisia. Analysis was previously performed to screen for mutations in leucine rich repeat kinase 2 (LRRK2), PTEN induced kinase 1 (PINK1) and parkin (PRKN). Clinical features were compared between patients with genetically undefined PD (n=107) and those with LRRK2 (n=73) and PINK1 (n=42) mutations using regression analyses adjusted for gender, age of onset and disease duration. PRKN cases (n=9) were too few for meaningful statistical analysis. In comparison with genetically undefined patients, LRRK2 mutation carriers had more severe motor symptoms (median Unified Parkinson's Disease Rating Scale scores approximately 1.6 times higher, p<0.001), a higher rate of dyskinesia (OR 4.21, p=0.002) and use of dopamine agonists (OR 3.64, p<0.001), and less postural tremor (OR 0.21, p<0.001). PINK1 mutation carriers presented an increased rate of drug induced dyskinesia (OR 3.81, p=0.007) and a lower rate of postural tremor (OR 0.16, p<0.001) than genetically undefined patients. As expected, PINK1 patients had younger ages and ages at disease onset, and a longer disease duration compared with LRRK2 mutation carriers and genetically undefined patients. Clinical differences between LRRK2, PINK1 and genetically undefined familial PD appear more pronounced than previously appreciated, and may prove useful in clinical practice. As future therapies are targeted to specific protein abnormalities, identifying the genetic causes and associated clinical and pathological features will determine diagnosis, preventative medicine and drug intervention strategies.

Comprehensive sequencing of the LRRK2 gene in patients with familial Parkinson's disease from North Africa.

The LRRK2 gene is a key player in Parkinson's disease (PD), however prevalence and pathogenicity of LRRK2 variants remain to be investigated in ethnically diverse populations. Herein, we performed comprehensive sequencing of the LRRK2 gene in 92 Tunisian probands with familial PD. We then performed an association study using all identified variants in a series of 167 Lrrk2 p.G2019S-negative patients with sporadic PD and 365 Lrrk2 p.G2019S-negative healthy control subjects, all from the same Arab-Berber ethnicity. We identified one novel coding substitution (p.M2408I) and 24 known coding changes. Only the Lrrk2 p.G2019S mutation segregated with disease within families and was found in 39% of familial probands. None of the variants displayed significant association with risk for sporadic PD, however a trend was observed for Lrrk2 p.Y2189C. The present study underscores the importance of the LRRK2 gene in the Tunisian PD population.

Cerebral venous thrombosis presenting with cerebellar ataxia and cortical blindness.

Venous infarction in the cerebellum has been reported only rarely, probably because of the abundant venous collateral drainage in this region. Bilateral occipital infarction is a rare cause of visual loss in cerebral venous thrombosis. We describe a 50-year-old woman with a history of ulcerative colitis who developed acute cerebellar ataxia and cortical blindness. She had bilateral cerebellar and occipital lesions related to sigmoid venous thrombosis and achieved complete recovery with anticoagulation therapy. Cerebral venous thrombosis should be considered in cases of simultaneous cerebellar and occipital vascular lesions.

ATP13A2 variability in Parkinson disease.

Recessively inherited mutations in ATP13A2 result in Kufor-Rakeb syndrome (KRS), whereas genetic variability and elevated ATP13A2 expression have been implicated in Parkinson disease (PD). Given this background, ATP13A2 was comprehensively assessed to support or refute its contribution to PD. Sequencing of ATP13A2 exons and intron-exon boundaries was performed in 89 probands with familial parkinsonism from Tunisia. The segregation of mutations with parkinsonism was subsequently assessed within pedigrees. The frequency of genetic variants and evidence for association was also examined in 240 patients with nonfamilial PD and 372 healthy controls. ATP13A2 mRNA expression was also quantified in brain tissues from 38 patients with nonfamilial PD and 38 healthy subjects from the United States. Sequencing analysis revealed 37 new variants; seven missense, six silent, and 24 that were noncoding. However, no single ATP13A2 mutation segregated with familial parkinsonism in either a dominant or recessive manner. Four markers showed marginal association with nonfamilial PD, prior to correction for multiple testing. ATP13A2 mRNA expression was marginally decreased in PD brains compared with tissue from control subjects. In conclusion, neither ATP13A2 genetic variability nor quantitative gene expression in brain appears to contribute to familial parkinsonism or nonfamilial PD.

Stroke in the Middle-East and North Africa: A 2-year prospective observational study of stroke characteristics in the region-Results from the Safe Implementation of Treatments in Stroke (SITS)-Middle-East and North African (MENA).

BACKGROUND AND METHODS: Stroke incidence and mortality are reported to have increased in the Middle-East and North African (MENA) countries during the last decade. This was a prospective observational study to examine the baseline characteristics of stroke patients in the MENA region and to compare the MENA vs. the non-MENA stroke cohort in the Safe Implementation of Treatments in Stroke (SITS) International Registry. RESULTS: Of the 13,822 patients with ischemic and hemorrhagic stroke enrolled in the SITS-All Patients Protocol between June 2014 and May 2016, 5897 patients (43%) were recruited in MENA. The median onset-to-door time was 5 h (IQR: 2:20-13:00), National Institutes of Health Stroke Scale (NIHSS) score was 8 (4-13) and age was 65 years (56-76). Hypertension (66%) and diabetes (38%) were the prevailing risk factors; large artery stenosis > 50% (25.3%) and lacunar strokes (24.1%) were the most common ischemic stroke etiologies. In comparison, non-MENA countries displayed an onset-to-door time of 5:50 h (2:00-18:45), a median of NIHSS 6 (3-14), and a median age of 66 (56-76), with other large vessel disease and cardiac embolism as the main ischemic stroke etiologies. Hemorrhagic strokes (10%) were less common compared to non-MENA countries (13.9%). In MENA, only a low proportion of patients (21%) was admitted to stroke units. CONCLUSIONS: MENA patients are slightly younger, have a higher prevalence of diabetes and slightly more severe ischemic strokes, commonly of atherosclerotic or microvascular etiology. Admission into stroke units and long-term follow-up need to be improved. It is suspected that cardiac embolism and atrial fibrillation are currently underdiagnosed in MENA countries.