Maria Luiza Saraiva-Pereira

ATP13A2 missense mutations in juvenile parkinsonism and young onset Parkinson disease

Objective: To assess the prevalence, nature, and associated phenotypes of ATP13A2 gene mutations among patients with juvenile parkinsonism (onset <21 years) or young onset (between 21 and 40 years) Parkinson disease (YOPD). Methods: We studied 46 patients, mostly from Italy or Brazil, including 11 with juvenile parkinsonism and 35 with YOPD. Thirty-three cases were sporadic and 13 had positive family history compatible with autosomal recessive inheritance. Forty-two had only parkinsonian signs, while four (all juvenile-onset) had multisystemic involvement. The whole ATP13A2 coding region (29 exons) and exon-intron boundaries were sequenced from genomic DNA. Results: A novel homozygous missense mutation (Gly504Arg) was identified in one sporadic case from Brazil with juvenile parkinsonism. This patient had symptoms onset at age 12, levodopa-responsive severe akinetic-rigid parkinsonism, levodopa-induced motor fluctuations and dyskinesias, severe visual hallucinations, and supranuclear vertical gaze paresis, but no pyramidal deficit nor dementia. Brain CT scan showed moderate diffuse atrophy. Furthermore, two Italian cases with YOPD without atypical features carried a novel missense mutation (Thr12Met, Gly533Arg) in single heterozygous state. Conclusions: We confirm that ATP13A2 homozygous mutations are associated with human parkinsonism, and expand the associated genotypic and clinical spectrum, by describing a homozygous missense mutation in this gene in a patient with a phenotype milder than that initially associated with ATP13A2 mutations (Kufor-Rakeb syndrome). Our data also suggest that ATP13A2 single heterozygous mutations might be etiologically relevant for patients with YOPD and further studies of this gene in Parkinson disease are warranted.

Nonmotor and extracerebellar features in Machado-Joseph disease: a review.

Spinocerebellar ataxia type 3 or Machado‐Joseph disease is the most common spinocerebellar ataxia worldwide, and the high frequency of nonmotor manifestations in Machado‐Joseph disease demonstrates how variable is the clinical expression of this single genetic entity. Anatomical, physiological, clinical, and functional neuroimaging data reinforce the idea of a degenerative process involving extracerebellar regions of the nervous system in Machado‐Joseph disease. Brain imaging and neuropathologic studies have revealed atrophy of the pons, basal ganglia, midbrain, medulla oblongata, multiple cranial nerve nuclei, and thalamus and of the frontal, parietal, temporal, occipital, and limbic lobes. This review provides relevant information about nonmotor manifestations and extracerebellar symptoms in Machado‐Joseph disease. The main nonmotor manifestations of Machado‐Joseph disease described in previous data and discussed in this article are: sleep disorders, cognitive and affective disturbances, psychiatric symptoms, olfactory dysfunction, peripheral neuropathy, pain, cramps, fatigue, nutritional problems, and dysautonomia. In addition, we conducted a brief discussion of noncerebellar motor manifestations, highlighting movement disorders.

Depressive Symptoms in Machado-Joseph Disease (SCA3) Patients and Their Relatives

Objectives: It was the aim of this study to determine the depression scores of Machado-Joseph disease (MJD) patients, their spouses, and individuals at 50% risk for MJD, and second, to verify the existence of a correlation between depressive symptoms and the degree of motor incapacitation. Subjects and Methods: Two hundred and forty-six individuals aged ≧18 years were studied: 79 MJD patients (group 1), 43 spouses of MJD patients (group 2), 80 individuals at risk for MJD (group 3), and a control group (group 4) composed of 44 patients with multiple sclerosis (MS). The following two tools were applied: the Beck Depression Inventory and the Barthel index of physical incapacitation, both in an adapted Brazilian Portuguese version. Results: Moderate to severe depressive scores were found in 33.5% of patients in the MJD families, in 16.3% of the spouses, and in 6.3% of the individuals at risk. This linear reduction between MJD family members was statistically significant (p < 0.0001, ANOVA). Depressive scores were also associated with age and the female sex. A direct correlation between Beck Depression Inventory scores and motor incapacitation was found in MJD patients (r = 0.507, Pearson correlation, p < 0.0001). Although the depressive symptoms in the control group with MS were higher than those found in MJD patients (59% of MS patients showed moderate to severe scores), depression did not correlate with physical incapacitation, age, or education attainment in the MS group. Conclusions: Depressive symptoms are rather common in MJD patients and in their spouses (caregivers). In this condition, depression seemed to be more reactive than primarily related to the disease process itself.

Ancestral origin of the ATTCT repeat expansion in spinocerebellar ataxia type 10 (SCA10)

Spinocerebellar ataxia type 10 (SCA10) is an autosomal dominant neurodegenerative disease characterized by cerebellar ataxia and seizures. The disease is caused by a large ATTCT repeat expansion in the ATXN10 gene. The first families reported with SCA10 were of Mexican origin, but the disease was soon after described in Brazilian families of mixed Portuguese and Amerindian ancestry. The origin of the SCA10 expansion and a possible founder effect that would account for its geographical distribution have been the source of speculation over the last years. To unravel the mutational origin and spread of the SCA10 expansion, we performed an extensive haplotype study, using closely linked STR markers and intragenic SNPs, in families from Brazil and Mexico. Our results showed (1) a shared disease haplotype for all Brazilian and one of the Mexican families, and (2) closely-related haplotypes for the additional SCA10 Mexican families; (3) little or null genetic distance in small normal alleles of different repeat sizes, from the same SNP lineage, indicating that they are being originated by a single step mechanism; and (4) a shared haplotype for pure and interrupted expanded alleles, pointing to a gene conversion model for its generation. In conclusion, we show evidence for an ancestral common origin for SCA10 in Latin America, which might have arisen in an ancestral Amerindian population and later have been spread into the mixed populations of Mexico and Brazil.

Body mass index is inversely correlated with the expanded CAG repeat length in SCA3/MJD patients.

Spinocerebellar ataxia type 3, also known as Machado–Joseph disease (SCA3/MJD), is an autosomal dominant neurodegenerative disorder with no current treatment. We aimed to evaluate the body mass index (BMI) of patients with SCA3/MJD and to assess the correlations with clinical, molecular, biochemical, and neuroimaging findings. A case–control study with 46 SCA3/MJD patients and 42 healthy, non-related control individuals with similar age and sex was performed. Clinical evaluation was done with the ataxia scales SARA and NESSCA. Serum insulin, insulin-like growth factor 1 (IGF-1) and magnetic resonance imaging normalized volumetries of cerebellum and brain stem were also assessed. BMI was lower in SCA3/MJD patients when compared to controls (p = 0.01). BMI was associated with NESSCA, expanded CAG repeat number (CAG)n, age of onset, age, disease duration, and serum insulin levels; however, in the linear regression model, (CAG)n was the only variable independently associated with BMI, in an inverse manner (R = −0.396, p = 0.015). In this report, we present evidence that low BMI is not only present in SCA3/MJD, but is also directly related to the length of the expanded CAG repeats, which is the causative mutation of the disease. This association points that weight loss might be a primary disturbance of SCA3/MJD, although further detailed analyses are necessary for a better understanding of the nutritional deficit and its role in the pathophysiology of SCA3/MJD.

Reduced penetrance of intermediate size alleles in spinocerebellar ataxia type 10

Triplet repeat expansions are the disease-causing mutations in nine dominantly inherited spinocerebellar ataxias (SCAs).1 In 2000, a new type of dynamic mutation was reported in Mexican patients with SCA and seizures, consisting of a (ATTCT)n expansion found in intron 9 of the SCA10 gene2; normal alleles have 10 to 29 and pathologic 800 to 4,500 repeats. We studied 329 unrelated SCA patients. Ataxia was sometimes associated with other features, such as epilepsy, mental retardation, seizures, paraplegia, or tremor; 290 were Portuguese, 39 were from Brazil. Peripheral blood was collected from patients and their relatives, after written informed consent. The (ATTCT)n was amplified by PCR with flanking primers and Southern blot was performed as described elsewhere.2,3 The modified PCR analysis for (ATTCT)n expansion showed that three patients (figure, A and B), from two unrelated Brazilian families, with an admixture of Portuguese and Amerindian ancestry, had a continuous ladder exceeding the product range observed for normal alleles at the SCA10 locus. These patients had first shown a single band after PCR for normal allele sizing (figure, C). Expansion size assessment (figure, D) identified one allele with 400 repeats in Patient II-2 …

The APOE ε2 Allele Increases the Risk of Earlier Age at Onset in Machado-Joseph Disease

OBJECTIVE To investigate a modulating effect of the apolipoprotein E (APOE) polymorphism on age at onset of Machado-Joseph disease (MJD). DESIGN We collected blood samples from 192 patients with MJD and typed the APOE polymorphism. Patients The 192 patients with MJD included 59 from the Azores, 73 from mainland Portugal, and 60 from Brazil. SETTING Academic research center. RESULTS Cases with the ε2/ε3 genotype had an earlier onset compared with those with the ε3/ε3 or the ε3/ε4 genotype. In this series of patients, the presence of an APOE ε2 allele implies a decrease of nearly 5 years in the age at onset. When combining several other predictors in a general linear model, namely, the presence/absence of the APOE ε2 allele, with the size of the (CAG)(n) in expanded alleles, the model was significantly improved and the explanation of onset variance was raised from 59.8% to 66.5%. Furthermore, the presence of the ε2 allele was associated with an onset before age 39 years (odds ratio, 5.00; 95% CI, 1.18-21.14). CONCLUSION The polymorphism at the APOE gene plays a role as a genetic modifier of MJD phenotype.

Parkinson's disease and the heterozygous state for glucocerebrosidase mutations among Brazilians

We have read with interest the publication by Spitz et al. [1] regarding their results on the association study of glucocerebrosidase mutations and Parkinson’s disease (PD) among Brazilian patients. Before them, several publications confirmed the association between PD and the heterozygote state for glucocerebrosidase (GBA) mutations in patients from Israel, USA, Canada, Norway, Venezuela, Taiwan (for a review see Refs. [1,2]), and now S~ao Paulo, Brazil. Table 1 summarizes these results. We also investigated the association between PD and GBA mutations in Brazilians by recruiting patients with PD in Porto Alegre, in the south of Brazil. PD was diagnosed according to the clinical criteria proposed by Gelb et al. [3]. Patients participated in the study, which was approved by the local and national ethics committees, after giving informed consent. A single neurologist (MS) examined all cases and performed a full neurological examination and applied the Hoehn and Yahr (HY) modified scale as well as the Unified PD rating scale (UPDRS). The study patients were unrelated. All patients had their GBA activity measured in their peripheral leukocytes using the standard 4-methylumbelliferyl-b-Dglycopyranoside assay. Activities below 10 nmol/h/mg were considered to be associated with an increased risk for the carrier state if they were confirmed in a second blood specimen. Common GBA mutations L444P, N370S, and IVS2þ1 were analyzed by PCR-RFLP using NciI, XhoI and HphI, respectively; while 84GG was analyzed by ARMS-PCR. The clinical data of the 62 (37 male) study patients are shown in Table 2. Mean SD age at examination was 50.14 10 yr.; mean SD age at onset was 41.4 10 yr. Patients were of Brazilian origin with mixed ethnic backgrounds, including Portuguese, Spanish, Italian, German, Amerindian and African ancestry. There were two (3.5%) heterozygotes for GD as follows: one carrying the N370S mutation and the other carrying the L444P mutation. Five patients, that is, the L444P carrier plus four additional patients without common mutations, had a leukocyte GBA activity below 10 nmol/h/mg of protein.

Brain-derived neurotrophic factor gene val66met polymorphism and executive functioning in patients with bipolar disorder

OBJECTIVE In the present study, we investigate the association between the val66met polymorphism of the brain-derived neurotrophic factor (BNDF) and the performance on the Wisconsin Card Sorting Test in a sample of Caucasian Brazilian patients with bipolar disorder. METHOD Sixty-four patients with bipolar disorder were assessed and their performance on the Wisconsin Card Sorting Test was compared with the allele frequency and genotype of the val66met polymorphism of the brain-derived neurotrophic factor. RESULTS The percentage of non-perseverative errors was significantly higher among patients with the val/val genotype. There was no association between (BNDF) genotype frequency and other Wisconsin Card Sorting Test domains. CONCLUSION Our results did not replicate previous descriptions of an association between a worse cognitive performance and the presence of the met allele of the val66met brain-derived neurotrophic factor gene polymorphism.

Identification of miRNAs that modulate glucocerebrosidase activity in Gaucher disease cells

Gaucher disease is an autosomal recessive disorder caused by deficiency of the enzyme glucocerebrosidase. Although it is a monogenic disease, there is vast phenotypic heterogeneity, even among patients with the same genotype. MicroRNAs (miRNAs) are small non-coding RNAs involved in many biological processes and diseases. To determine whether miRNAs can affect glucocerebrosidase activity, we performed a screen of 875 different miRNA mimics. The screen was performed using Gaucher fibroblasts, and glucocerebrosidase activity was used as the initial outcome parameter. We found several miRNAs that either up- or down-regulated glucocerebrosidase activity. In follow-up assays, we confirmed that one specific miRNA (miR-127–5p) down-regulated both glucocerebrosidase activity and protein levels by down-regulation of LIMP-2, the receptor involved in proper trafficking of glucocerebrosidase from the endoplasmic reticulum to the lysosome. A conditioned media assay demonstrated that cells treated with this miRNA secreted glucocerebrosidase into the extracellular environment, supporting impaired LIMP-2 function. Two other miRNAs, miR-16–5p and miR-195–5p, were found to up-regulate glucocerebrosidase activity by greater than 40% and to enhance expression and protein levels of the enzyme. In conclusion, we show that miRNAs can alter glucocerebrosidase activity in patient cells, indicating that miRNAs can potentially act as modifiers in Gaucher disease.