Vítor Tedim Cruz

Mutations in SPG11 , encoding spatacsin, are a major cause of spastic paraplegia with thin corpus callosum

Autosomal recessive hereditary spastic paraplegia (ARHSP) with thin corpus callosum (TCC) is a common and clinically distinct form of familial spastic paraplegia that is linked to the SPG11 locus on chromosome 15 in most affected families. We analyzed 12 ARHSP-TCC families, refined the SPG11 candidate interval and identified ten mutations in a previously unidentified gene expressed ubiquitously in the nervous system but most prominently in the cerebellum, cerebral cortex, hippocampus and pineal gland. The mutations were either nonsense or insertions and deletions leading to a frameshift, suggesting a loss-of-function mechanism. The identification of the function of the gene will provide insight into the mechanisms leading to the degeneration of the corticospinal tract and other brain structures in this frequent form of ARHSP.

Citicoline in the treatment of acute ischaemic stroke: an international, randomised, multicentre, placebo-controlled study (ICTUS trial)

BACKGROUND Citicoline is approved in some countries for the treatment of acute ischaemic stroke. The drug has shown some evidence of efficacy in a pooled analysis. We sought to confirm the efficacy of citicoline in a larger trial. METHODS We undertook a randomised, placebo-controlled, sequential trial in patients with moderate-to-severe acute ischaemic stroke admitted at university hospitals in Germany, Portugal, and Spain. Using a centralised minimisation process, patients were randomly assigned in a 1:1 ratio to receive citicoline or placebo within 24 h after the onset of symptoms (1000 mg every 12 h intravenously during the first 3 days and orally thereafter for a total of 6 weeks [2×500 mg oral tablets given every 12 h]). All study participants were masked. The primary outcome was recovery at 90 days measured by a global test combining three measures of success: National Institutes of Health Stroke Scale ≤1, modified Rankin score ≤1, and Barthel Index ≥95. Safety endpoints included symptomatic intracranial haemorrhage in patients treated with recombinant tissue plasminogen activator, neurological deterioration, and mortality. This trial is registered, NCT00331890. RESULTS 2298 patients were enrolled into the study from Nov 26, 2006, to Oct 27, 2011. 37 centres in Spain, 11 in Portugal, and 11 in Germany recruited patients. Of the 2298 patients who gave informed consent and underwent randomisation, 1148 were assigned to citicoline and 1150 to placebo. The trial was stopped for futility at the third interim analysis on the basis of complete data from 2078 patients. The final randomised analysis was based on data for 2298 patients: 1148 in citicoline group and 1150 in placebo group. Global recovery was similar in both groups (odds ratio 1·03, 95% CI 0·86-1·25; p=0·364). No significant differences were reported in the safety variables nor in the rate of adverse events. INTERPRETATION Under the circumstances of the ICTUS trial, citicoline is not efficacious in the treatment of moderate-to-severe acute ischaemic stroke. FUNDING Ferrer Grupo.

Mutations of the GLA Gene in Young Patients With Stroke The PORTYSTROKE Study—Screening Genetic Conditions in PORTuguese Young STROKE Patients

Background and Purpose— Fabry disease is an X-linked monogenic disorder caused by mutations in the GLA gene. Recent data suggest that stroke in young adults may be associated with Fabry disease. We aimed to ascertain the prevalence of this disorder among young adult patients with stroke in Portugal by GLA genotyping. Methods— During 1 year, all patients aged 18 to 55 years with first-ever stroke, who were admitted into any of 12 neurology hospital departments in Portugal, were prospectively enrolled (n=625). Ischemic stroke was classified according to Trial of Org 10172 in Acute Stroke Treatment criteria. Alpha-galactosidase activity was further assayed in all patients with GLA mutations. Results— Four hundred ninety-three patients (mean age, 45.4 years; 61% male) underwent genetic analyses: 364 with ischemic stroke, 89 with intracerebral hemorrhage, 26 with subarachnoid hemorrhage, and 14 with cerebral venous thrombosis. Twelve patients had missense GLA mutations: 9 with ischemic stroke (p.R118C: n=4; p.D313Y: n=5), including 5 patients with an identified cause of stroke (cardiac embolism: n=2; small vessel disease: n=2; other cause: n=1), 2 with intracerebral hemorrhage (p.R118C: n=1; p.D313Y: n=1), and one with cerebral venous thrombosis (p.R118C: n=1). Leukocyte &agr;-galactosidase activity was subnormal in the hemizygous males and subnormal or low-normal in the heterozygous females. Estimated prevalence of missense GLA mutations was 2.4% (95% CI, 1.3% to 4.1%). Conclusions— Despite a low diagnostic yield, screening for GLA mutations should probably be considered in different types of stroke. Restricting investigation to patients with cryptogenic stroke may underestimate the true prevalence of Fabry disease in young patients with stroke.

Prevalence and pattern of cognitive impairment in rural and urban populations from Northern Portugal.

BackgroundDespite worldwide recognition of the burden of dementia, no epidemiological data is yet available in Portugal. The objective of this study is to estimate the prevalence and describe the pattern of cognitive impairment with dementia or no dementia (CIND) in rural and urban populations from Northern Portugal.MethodsTwo random samples of residents aged 55 to 79 years in rural and urban communities were drawn from the health centres registries to be screened for cognitive impairment. The screening criteria for dementia were an abnormal Mini-Mental State Examination (MMSE) score or a Blessed Dementia Scale score. After excluding those who tested positive for dementia, cut-off points for CIND were set at 1 standard deviation below the mean of the MMSE according to educational level. All those who screened positive either for dementia or CIND were examined by a neurologist for establishing a definitive diagnosis.ResultsThe prevalence of cognitive impairment was higher in rural than in urban populations, 16.8% (95% CI: 14.3-19.8%) vs. 12.0% (95%CI: 9.3-15.4%), with a rural/urban prevalence ratio (PR) of 2.16 (95% CI: 1.04-4.50) in the eldest and 2.19 (95% CI: 1.01-4.76) in persons with vascular risk factors. The prevalence of dementia was 2.7% (95% CI: 1.9-3.8%) with a rural/urban PR = 2.1 and the prevalence of CIND was 12.3% (95% CI: 10.4-14.4%) and PR = 1.3. The prevalence of dementia increases exponentially with age and in those with cerebrovascular disease or other comorbid conditions while the prevalence of CIND, besides these factors, is also higher in persons with low levels of education or vascular risk factors. Alzheimers and vascular disease were equally likely aetiologies of dementia (38.7%), the later more common in men PR(F:M = 0.3) as opposed to the former PR(F:M = 2.0). Vascular CIND, associated either with cerebrovascular disease or vascular risk factors was more frequent (39.7%) then depression (18.4%) or any other aetiology.ConclusionsThe prevalence of cognitive impairment is higher in rural compared with urban populations. This is shown in the synergy between age and rurality, with the rural/urban prevalence ratio increasing with age. In this relatively young population from Northern Portugal, cerebrovascular disease as well as vascular risk factors account for 48% of overall cognitive impairment.

Alteration of Ganglioside Biosynthesis Responsible for Complex Hereditary Spastic Paraplegia

Hereditary spastic paraplegias (HSPs) form a heterogeneous group of neurological disorders. A whole-genome linkage mapping effort was made with three HSP-affected families from Spain, Portugal, and Tunisia and it allowed us to reduce the SPG26 locus interval from 34 to 9 Mb. Subsequently, a targeted capture was made to sequence the entire exome of affected individuals from these three families, as well as from two additional autosomal-recessive HSP-affected families of German and Brazilian origins. Five homozygous truncating (n = 3) and missense (n = 2) mutations were identified in B4GALNT1. After this finding, we analyzed the entire coding region of this gene in 65 additional cases, and three mutations were identified in two subjects. All mutated cases presented an early-onset spastic paraplegia, with frequent intellectual disability, cerebellar ataxia, and peripheral neuropathy as well as cortical atrophy and white matter hyperintensities on brain imaging. B4GALNT1 encodes β-1,4-N-acetyl-galactosaminyl transferase 1 (B4GALNT1), involved in ganglioside biosynthesis. These findings confirm the increasing interest of lipid metabolism in HSPs. Interestingly, although the catabolism of gangliosides is implicated in a variety of neurological diseases, SPG26 is only the second human disease involving defects of their biosynthesis.

Neuroferritinopathy: missense mutation in FTL causing early-onset bilateral pallidal involvement.

The authors identified a missense mutation in the FTL gene (474G>A; A96T) in a 19-year-old man with parkinsonism, ataxia, corticospinal signs, mild nonprogressive cognitive deficit, and episodic psychosis. This mutation was also present in his asymptomatic mother and younger brother, who had abnormally low levels of ferritin in the serum. The patient and his mother displayed bilateral involvement of the pallidum.

WRN mutations in Werner syndrome patients: genomic rearrangements, unusual intronic mutations and ethnic-specific alterations

Werner syndrome (WS) is an autosomal recessive segmental progeroid syndrome caused by null mutations at the WRN locus, which codes for a member of the RecQ family of DNA helicases. Since 1988, the International Registry of Werner syndrome had enrolled 130 molecularly confirmed WS cases from among 110 worldwide pedigrees. We now report 18 new mutations, including two genomic rearrangements, a deep intronic mutation resulting in a novel exon, a splice consensus mutation leading to utilization of the nearby splice site, and two rare missense mutations. We also review evidence for founder mutations among various ethnic/geographic groups. Founder WRN mutations had been previously reported in Japan and Northern Sardinia. Our Registry now suggests characteristic mutations originated in Morocco, Turkey, The Netherlands and elsewhere.

Hereditary ataxia and spastic paraplegia in Portugal: a population-based prevalence study.

IMPORTANCE Epidemiological data on hereditary cerebellar ataxia (HCA) and hereditary spastic paraplegia (HSP) are scarce. OBJECTIVE To present the prevalence and distribution of HCA and HSP in Portugal. DESIGN AND SETTING Population-based, nationwide, systematic survey, from January 1, 1994, through April 15, 2004, in Portugal. PARTICIPANTS Multiple sources of information were used (review of clinical files, active collaboration of neurologists and geneticists, and investigation of affected families), but the main source was active collaboration of general practitioners. Patients were examined by the same team of neurologists, using homogeneous inclusion criteria. The clinical data were registered, and all families were genetically tested. RESULTS Overall, 1336 patients from a population of 10,322 million were diagnosed as having HCA or HSP, a prevalence of 12.9 per 100,000 population. Hereditary cerebellar ataxia was more prevalent (prevalence, 8.9 per 100,000 population; 5.6 for dominant and 3.3 for recessive ataxias) than HSP (prevalence, 4.1 per 100,000 population; 2.4 for dominant and 1.6 for recessive). Machado-Joseph disease (spinocerebellar ataxia type 3) (prevalence, 3.1 per 100,000 population), Friedreich ataxia (prevalence, 1.0 per 100,000 population), and ataxia with oculomotor apraxia (prevalence, 0.4 per 100,000 population) were the most frequent HCAs. Spastic paraplegia types 4 (prevalence, 0.91 per 100,000 population), 3 (prevalence, 0.14 per 100,000 population), and 11 (prevalence, 0.26 per 100,000 population) were the most prevalent HSPs. CONCLUSIONS AND RELEVANCE This population-based survey covered all the Portuguese territory and mobilized most general practitioners and health centers. To our best knowledge, this survey was the largest ever performed for HCA and HSP. Prevalence of autosomal dominant ataxias was high, particularly for Machado-Joseph disease (spinocerebellar ataxia type 3). The genetic cause has not been identified in 39.7% of the patients studied.

A novel H101Q mutation causes PKCγ loss in spinocerebellar ataxia type 14

AbstractSpinocerebellar ataxia type 14 (SCA14) is an autosomal dominant neurodegenerative disorder, first described in a Japanese family, showing linkage to chromosome 19q13.4-qter. Recently, mutations have been identified in the PRKCG gene in families with SCA14. The PRKCG gene encodes the protein kinase Cγ (PKCγ), a member of a serine/threonine kinase family involved in signal transduction important for several cellular processes, including cell proliferation and synaptic transmission. To identify the disease-causing mutation in a large group of ataxia patients, we searched for mutations in the PRKCG gene. We ascertained 366 unrelated patients with spinocerebellar ataxia, either pure or with associated features such as epilepsy, mental retardation, seizures, paraplegia, and tremor. A C-to-G transversion in exon 4, resulting in a histidine-to-glutamine change at codon 101 of the PKCγ protein, was identified in patients from a family with slowly progressive pure cerebellar ataxia. Functional studies performed in HEK293 cells transfected with normal or mutant construct showed that this mutation affects PKCγ stability or solubility, verified by time-dependent decreased protein levels in cell culture. In conclusion, the H101Q mutation causes slowly progressive uncomplicated ataxia by interfering with PKCγ stability or solubility, which consequently may cause in either case a decrease in the overall PKCγ-dependent phosphorylation.

A new locus for autosomal recessive spastic paraplegia (SPG32) on chromosome 14q12-q21

Hereditary spastic paraplegias (HSPs) are a group of neurodegenerative disorders characterized by progressive spasticity of the lower limbs. Here, we performed a genome-wide linkage analysis on a consanguineous family presenting an autosomal recessive form of HSP associated with mild mental retardation, brainstem dysraphia, and clinically asymptomatic cerebellar atrophy. We have mapped the disease locus SPG32 to chromosome 14q12-q21 within a 30-cM interval, which excludes the atlastin gene.