Quantitative Oculomotor Assessment in Hereditary Ataxia: Discriminatory Power, Correlation with Severity Measures, and Recommended Parameters for Specific Genotypes.

Characterizing bedside oculomotor deficits is a critical factor in defining the clinical presentation of hereditary ataxias. Quantitative assessments are increasingly available and have significant advantages, including comparability over time, reduced examiner dependency, and sensitivity to subtle changes. To delineate the potential of quantitative oculomotor assessments as digital-motor outcome measures for clinical trials in ataxia, we searched MEDLINE for articles reporting on quantitative eye movement recordings in genetically confirmed or suspected hereditary ataxias, asking which paradigms are most promising for capturing disease progression and treatment response. Eighty-nine manuscripts identified reported on 1541 patients, including spinocerebellar ataxias (SCA2, n = 421), SCA3 (n = 268), SCA6 (n = 117), other SCAs (n = 97), Friedreich ataxia (FRDA, n = 178), Niemann-Pick disease type C (NPC, n = 57), and ataxia-telangiectasia (n = 85) as largest cohorts. Whereas most studies reported discriminatory power of oculomotor assessments in diagnostics, few explored their value for monitoring genotype-specific disease progression (n = 2; SCA2) or treatment response (n = 8; SCA2, FRDA, NPC, ataxia-telangiectasia, episodic-ataxia 4). Oculomotor parameters correlated with disease severity measures including clinical scores (n = 18 studies (SARA: n = 9)), chronological measures (e.g., age, disease duration, time-to-symptom onset; n = 17), genetic stratification (n = 9), and imaging measures of atrophy (n = 5). Recurrent correlations across many ataxias (SCA2/3/17, FRDA, NPC) suggest saccadic eye movements as potentially generic quantitative oculomotor outcome. Recommendation of other paradigms was limited by the scarcity of cross-validating correlations, except saccadic intrusions (FRDA), pursuit eye movements (SCA17), and quantitative head-impulse testing (SCA3/6). This work aids in understanding the current knowledge of quantitative oculomotor parameters in hereditary ataxias, and identifies gaps for validation as potential trial outcome measures in specific ataxia genotypes.

Cognitive-affective manifestations since premanifest phases of Spinocerebellar Ataxia Type 3/Machado-Joseph Disease.

BACKGROUND: Cognitive deficits were related to Spinocerebellar Ataxia type 3/Machado-Joseph Disease (SCA3/MJD), but the Cerebellar Cognitive Affective Syndrome (CCAS) needs further investigation in this disorder. We aimed to characterize cognitive-affective deficits in manifest and premanifest SCA3/MJD carriers. METHODS: Subjects at 50% risk, manifest carriers and unrelated controls were evaluated in-person or in virtual settings with CCAS Scale (CCAS-S), Stroop Color-Word Test (SCWT), Trail-Making Test (TMT), and Reading the Mind in the Eyes Test (RMET). Scale for Assessment and Rating of Ataxia (SARA) >2.5 or Friedreich Ataxia Rating Scale/Activities of Daily Living (FARS-adl) >4 divided carriers into manifest and premanifest. Time after onset or time left to gait ataxia onset (TimeToAfterOnset) were estimated. Differences between groups and correlations with TimeToAfterOnset, SARA and FARS-adl were checked. RESULTS: After random selection to balance groups, 23 manifest and 35 premanifest carriers, and 58 controls were included. CCAS-S, semantic fluency, phonemic fluency, category switching, affect, SCWT, and RMET showed significant differences between manifest carriers and controls; premanifest carriers mostly displayed intermediate values between controls and manifest carriers. These variables correlated with TimeToAfterOnset and SARA scores of the carriers. Correlations with SARA were stronger in the pre-ataxic group. CCAS-S had the strongest correlations with time and SARA. DISCUSSION: Cognitive-affective deficits in SCA3/MJD involve executive function, language, affect, and social cognition, which seem to be altered prior to the ataxia onset, and correlate with markers of motor progression. CCAS-S was the most promising biomarker and should be evaluated in longitudinal studies.

Quantitative Oculomotor Assessment in Hereditary Ataxia: Systematic Review and Consensus by the Ataxia Global Initiative Working Group on Digital-motor Biomarkers.

Oculomotor deficits are common in hereditary ataxia, but disproportionally neglected in clinical ataxia scales and as outcome measures for interventional trials. Quantitative assessment of oculomotor function has become increasingly available and thus applicable in multicenter trials and offers the opportunity to capture severity and progression of oculomotor impairment in a sensitive and reliable manner. In this consensus paper of the Ataxia Global Initiative Working Group On Digital Oculomotor Biomarkers, based on a systematic literature review, we propose harmonized methodology and measurement parameters for the quantitative assessment of oculomotor function in natural-history studies and clinical trials in hereditary ataxia. MEDLINE was searched for articles reporting on oculomotor/vestibular properties in ataxia patients and a study-tailored quality-assessment was performed. One-hundred-and-seventeen articles reporting on subjects with genetically confirmed (n=1134) or suspected hereditary ataxia (n=198), and degenerative ataxias with sporadic presentation (n=480) were included and subject to data extraction. Based on robust discrimination from controls, correlation with disease-severity, sensitivity to change, and feasibility in international multicenter settings as prerequisite for clinical trials, we prioritize a core-set of five eye-movement types: (i) pursuit eye movements, (ii) saccadic eye movements, (iii) fixation, (iv) eccentric gaze holding, and (v) rotational vestibulo-ocular reflex. We provide detailed guidelines for their acquisition, and recommendations on the quantitative parameters to extract. Limitations include low study quality, heterogeneity in patient populations, and lack of longitudinal studies. Standardization of quantitative oculomotor assessments will facilitate their implementation, interpretation, and validation in clinical trials, and ultimately advance our understanding of the evolution of oculomotor network dysfunction in hereditary ataxias.

Machado Joseph-Disease Is Rare in the Peruvian Population.

Spinocerebellar ataxia type 3 or Machado-Joseph disease (MJD/SCA3) is the most prevalent autosomal dominant cerebellar ataxia worldwide, but its frequency varies by geographic region. We describe MJD/SCA3 patients diagnosed in a tertiary healthcare institution in Peru. In a cohort of 341 individuals (253 probands) with clinical ataxia diagnosis, seven MJD/SCA3 probands were identified and their pedigrees extended, detecting a total of 18 MJD/SCA3 cases. Out of 506 alleles from all probands from this cohort, the 23-CAG repeat was the most common ATXN3 allele (31.8%), followed by the 14-CAG repeat allele (26.1%). Normal alleles ranged from 12 to 38 repeats while pathogenic alleles ranged from 64 to 75 repeats. We identified 80 large normal (LN) alleles (15.8%). Five out of seven families declared an affected family member traced back to foreign countries (England, Japan, China, and Trinidad and Tobago). MJD/SCA3 patients showed ataxia, accompanied by pyramidal signs, dysarthria, and dysphagia as well as abnormal oculomotor movements. In conclusion, ATXN3 allelic distribution in non-MJD/SCA3 patients with ataxia is similar to the distribution in normal individuals around the world, whereas LN allele frequency reinforces no correlation with the frequency of MJD/SCA3. Evidence of any atypical MJD/SCA3 phenotype was not found. Furthermore, haplotypes are required to confirm the foreign origin of MJD/SCA3 in the Peruvian population.

CAG Repeat Size Influences the Progression Rate of Spinocerebellar Ataxia Type 3.

OBJECTIVE: In spinocerebellar ataxia type 3/Machado-Joseph disease (SCA3/MJD), the expanded cytosine adenine guanine (CAG) repeat in ATXN3 is the causal mutation, and its length is the main factor in determining the age at onset (AO) of clinical symptoms. However, the contribution of the expanded CAG repeat length to the rate of disease progression after onset has remained a matter of debate, even though an understanding of this factor is crucial for experimental data on disease modifiers and their translation to clinical trials and their design. METHODS: Eighty-two Dutch patients with SCA3/MJD were evaluated annually for 15 years using the International Cooperative Ataxia Rating Scale (ICARS). Using linear growth curve models, ICARS progression rates were calculated and tested for their relation to the length of the CAG repeat expansion and to the residual age at onset (RAO): The difference between the observed AO and the AO predicted on the basis of the CAG repeat length. RESULTS: On average, ICARS scores increased 2.57 points/year of disease. The length of the CAG repeat was positively correlated with a more rapid ICARS progression, explaining 30% of the differences between patients. Combining both the length of the CAG repeat and RAO as comodifiers explained up to 47% of the interpatient variation in ICARS progression. INTERPRETATION: Our data imply that the length of the expanded CAG repeat in ATXN3 is a major determinant of clinical decline, which suggests that CAG-dependent molecular mechanisms similar to those responsible for disease onset also contribute to the rate of disease progression in SCA3/MJD. ANN NEUROL 2021;89:66-73.

Genome-wide association study identifies genetic factors that modify age at onset in Machado-Joseph disease.

Machado-Joseph disease (MJD/SCA3) is the most common form of dominantly inherited ataxia worldwide. The disorder is caused by an expanded CAG repeat in the ATXN3 gene. Past studies have revealed that the length of the expansion partly explains the disease age at onset (AO) variability of MJD, which is confirmed in this study (Pearson's correlation coefficient R2 = 0.62). Using a total of 786 MJD patients from five different geographical origins, a genome-wide association study (GWAS) was conducted to identify additional AO modifying factors that could explain some of the residual AO variability. We identified nine suggestively associated loci (P < 1 × 10-5). These loci were enriched for genes involved in vesicle transport, olfactory signaling, and synaptic pathways. Furthermore, associations between AO and the TRIM29 and RAG genes suggests that DNA repair mechanisms might be implicated in MJD pathogenesis. Our study demonstrates the existence of several additional genetic factors, along with CAG expansion, that may lead to a better understanding of the genotype-phenotype correlation in MJD.

ATXN10 Microsatellite Distribution in a Peruvian Amerindian Population.

Spinocerebellar ataxia type 10 (SCA10) is a repeat expansion disease occurring mostly in Latin America, suggesting that the mutation spread with the peopling of the Americas, or that Amerindian populations, have a higher ATXN10 mutability. High frequency of large normal alleles is associated with prevalence and relative frequency of other repeat expansion diseases. To test whether the allele distribution of the SCA10-causing ATXN10 microsatellite in an Amerindian Peruvian population differs from that of other populations. The ATXN10 allele distribution in a Quechua Peruvian population from Puno, Peru, is similar to that of Finland. Mean allele size and mode were also similar to those of Mexico, Japan, and white Europeans. ATXN10 allele distribution in a healthy Amerindian population from Peru does not differ from that of other populations.

Ophthalmological and Neurologic Manifestations in Pre-clinical and Clinical Phases of Spinocerebellar Ataxia Type 7.

Spinocerebellar ataxia type 7 (SCA7) is a polyglutamine disease that progressively affects the cerebellum, brainstem, and retina. SCA7 is quite rare, and insights into biomarkers and pre-clinical phases are still missing. We aimed to describe neurologic and ophthalmological findings observed in symptomatic and pre-symptomatic SCA7 subjects. Several neurologic scales, visual acuity, visual fields obtained by computer perimetry, and macular thickness in optical coherence tomography (mOCT) were measured in symptomatic carriers and at risk relatives. Molecular analysis of the ATXN7 was done blindly in individuals at risk. Thirteen symptomatic carriers, 3 pre-symptomatic subjects, and 5 related controls were enrolled. Symptomatic carriers presented scores significantly different from those of controls in most neurologic and ophthalmological scores. Gradual changes from controls to pre-symptomatic and then to symptomatic carriers were seen in mean (SD) of visual fields - 1.34 (1.15), - 2.81 (1.66). and - 9.56 (7.26); mOCT - 1.11 (2.6), - 3.48 (3.54), and - 7.73 (2.56) Z scores; and "Spinocerebellar Ataxia Functional Index (SCAFI)" - 1.16 (0.28), 0.65 (0.56), and - 0.61 (0.44), respectively. Visual fields and SCAFI were significantly correlated with time to disease onset (pre-symptomatic)/disease duration (symptomatic carriers). Visual fields, mOCT, and SCAFI stood out as candidates for state biomarkers for SCA7 since pre-symptomatic stages of disease.

Oxidative Imbalance, Nitrative Stress, and Inflammation in C6 Glial Cells Exposed to Hexacosanoic Acid: Protective Effect of N-acetyl-L-cysteine, Trolox, and Rosuvastatin.

X-linked adrenoleukodystrophy (X-ALD) is an inherited neurometabolic disorder caused by disfunction of the ABCD1 gene, which encodes a peroxisomal protein responsible for the transport of the very long-chain fatty acids from the cytosol into the peroxisome, to undergo ß-oxidation. The mainly accumulated saturated fatty acids are hexacosanoic acid (C26:0) and tetracosanoic acid (C24:0) in tissues and body fluids. This peroxisomal disorder occurs in at least 1 out of 20,000 births. Considering that pathophysiology of this disease is not well characterized yet, and glial cells are widely used in studies of protective mechanisms against neuronal oxidative stress, we investigated oxidative damages and inflammatory effects of vesicles containing lecithin and C26:0, as well as the protection conferred by N-acetyl-L-cysteine (NAC), trolox (TRO), and rosuvastatin (RSV) was assessed. It was verified that glial cells exposed to C26:0 presented oxidative DNA damage (measured by comet assay and endonuclease III repair enzyme), enzymatic oxidative imbalance (high catalase activity), nitrative stress [increased nitric oxide (NO) levels], inflammation [high Interleukin-1beta (IL-1ß) levels], and induced lipid peroxidation (increased isoprostane levels) compared to native glial cells without C26:0 exposure. Furthermore, NAC, TRO, and RSV were capable to mitigate some damages caused by the C26:0 in glial cells. The present work yields experimental evidence that inflammation, oxidative, and nitrative stress may be induced by hexacosanoic acid, the main accumulated metabolite in X-ALD, and that antioxidants might be considered as an adjuvant therapy for this severe neurometabolic disease.

Huntington's disease-like disorders in Latin America and the Caribbean.

Diseases with a choreic phenotype can be due to a variety of genetic etiologies. As testing for Huntington's disease (HD) becomes more available in previously resource-limited regions, it is becoming apparent that there are patients in these areas with other rare genetic conditions which cause an HD-like phenotype. Documentation of the presence of these conditions is important in order to provide appropriate diagnostic and clinical care for these populations. Information for this article was gathered in two ways; the literature was surveyed for publications reporting a variety of genetic choreic disorders, and movement disorders specialists from countries in Latin America and the Caribbean were contacted regarding their experiences with chorea of genetic etiology. Here we discuss the availability of molecular diagnostics for HD and for other choreic disorders, along with a summary of the published reports of affected subjects, and authors' personal experiences from the regions. While rare, patients affected by non-HD genetic choreas are evidently present in Latin America and the Caribbean. HD-like 2 is particularly prevalent in countries where the population has African ancestry. The incidence of other conditions is likely determined by other variations in ethnic background and settlement patterns. As genetic resources and awareness of these disorders improve, more patients are likely to be identified, and have the potential to benefit from education, support, and ultimately molecular therapies.

Population-specific genetic modification of Huntington's disease in Venezuela.

Modifiers of Mendelian disorders can provide insights into disease mechanisms and guide therapeutic strategies. A recent genome-wide association (GWA) study discovered genetic modifiers of Huntington's disease (HD) onset in Europeans. Here, we performed whole genome sequencing and GWA analysis of a Venezuelan HD cluster whose families were crucial for the original mapping of the HD gene defect. The Venezuelan HD subjects develop motor symptoms earlier than their European counterparts, implying the potential for population-specific modifiers. The main Venezuelan HD family inherits HTT haplotype hap.03, which differs subtly at the sequence level from European HD hap.03, suggesting a different ancestral origin but not explaining the earlier age at onset in these Venezuelans. GWA analysis of the Venezuelan HD cluster suggests both population-specific and population-shared genetic modifiers. Genome-wide significant signals at 7p21.2-21.1 and suggestive association signals at 4p14 and 17q21.2 are evident only in Venezuelan HD, but genome-wide significant association signals at the established European chromosome 15 modifier locus are improved when Venezuelan HD data are included in the meta-analysis. Venezuelan-specific association signals on chromosome 7 center on SOSTDC1, which encodes a bone morphogenetic protein antagonist. The corresponding SNPs are associated with reduced expression of SOSTDC1 in non-Venezuelan tissue samples, suggesting that interaction of reduced SOSTDC1 expression with a population-specific genetic or environmental factor may be responsible for modification of HD onset in Venezuela. Detection of population-specific modification in Venezuelan HD supports the value of distinct disease populations in revealing novel aspects of a disease and population-relevant therapeutic strategies.

Haplotype Study in SCA10 Families Provides Further Evidence for a Common Ancestral Origin of the Mutation.

Spinocerebellar ataxia type 10 (SCA10) is an autosomal dominant neurodegenerative disorder characterized by progressive cerebellar ataxia and epilepsy. The disease is caused by a pentanucleotide ATTCT expansion in intron 9 of the ATXN10 gene on chromosome 22q13.3. SCA10 has shown a geographical distribution throughout America with a likely degree of Amerindian ancestry from different countries so far. Currently available data suggest that SCA10 mutation might have spread out early during the peopling of the Americas. However, the ancestral origin of SCA10 mutation remains under speculation. Samples of SCA10 patients from two Latin American countries were analysed, being 16 families from Brazil (29 patients) and 21 families from Peru (27 patients) as well as 49 healthy individuals from Indigenous Quechua population and 51 healthy Brazilian individuals. Four polymorphic markers spanning a region of 5.2 cM harbouring the ATTCT expansion were used to define the haplotypes, which were genotyped by different approaches. Our data have shown that 19-CGGC-14 shared haplotype was found in 47% of Brazilian and in 63% of Peruvian families. Frequencies from both groups are not statistically different from Quechua controls (57%), but they are statistically different from Brazilian controls (12%) (p < 0.001). The most frequent expanded haplotype in Quechuas, 19-15-CGGC-14-10, is found in 50% of Brazilian and in 65% of Peruvian patients with SCA10. These findings bring valuable evidence that ATTCT expansion may have arisen in a Native American chromosome.

Chaperones in Polyglutamine Aggregation: Beyond the Q-Stretch.

Expanded polyglutamine (polyQ) stretches in at least nine unrelated proteins lead to inherited neuronal dysfunction and degeneration. The expansion size in all diseases correlates with age at onset (AO) of disease and with polyQ protein aggregation, indicating that the expanded polyQ stretch is the main driving force for the disease onset. Interestingly, there is marked interpatient variability in expansion thresholds for a given disease. Between different polyQ diseases the repeat length vs. AO also indicates the existence of modulatory effects on aggregation of the upstream and downstream amino acid sequences flanking the Q expansion. This can be either due to intrinsic modulation of aggregation by the flanking regions, or due to differential interaction with other proteins, such as the components of the cellular protein quality control network. Indeed, several lines of evidence suggest that molecular chaperones have impact on the handling of different polyQ proteins. Here, we review factors differentially influencing polyQ aggregation: the Q-stretch itself, modulatory flanking sequences, interaction partners, cleavage of polyQ-containing proteins, and post-translational modifications, with a special focus on the role of molecular chaperones. By discussing typical examples of how these factors influence aggregation, we provide more insight on the variability of AO between different diseases as well as within the same polyQ disorder, on the molecular level.

Nonneurological Involvement in Late-Onset Friedreich Ataxia (LOFA): Exploring the Phenotypes.

Friedreich's ataxia (FDRA) is the most common inherited ataxia worldwide, caused by homozygous GAA expansions in the FXN gene. Patients usually have early onset ataxia, areflexia, Babinski sign, scoliosis and pes cavus, but at least 25 % of cases have atypical phenotypes. Disease begins after the age of 25 in occasional patients (late-onset Friedreich ataxia (LOFA)). Little is known about the frequency and clinical profile of LOFA patients. One hundred six patients with molecular confirmation of FDRA and followed in three Brazilian outpatient centers were enrolled. General demographics, GAA expansion size, age at onset, cardiac, endocrine, and skeletal manifestations were evaluated and compared between LOFA and classic FDRA (cFDRA) groups. We used Mann-Whitney and Fisher tests to compare means and proportions between groups; p values <0.05 were considered significant. LOFA accounted for 17 % (18/106) and cFDRA for 83 % (88/106) of the patients. There were 13 and 48 women in each group, respectively. LOFA patients were significantly older and had smaller GAA expansions. Clinically, LOFA group had a tendency toward lower frequency of diabetes/impaired glucose tolerance (5.8 vs. 17 %, p = 0.29) and cardiomyopathy (16.6 vs. 28.4 %, p = 0.38). Skeletal abnormalities were significantly less frequent in LOFA (scoliosis 22 vs. 61 %, p = 0.003, and pes cavus 22 vs.75 %, p < 0.001) as were spasticity and sustained reflexes, found in 22 % of LOFA patients but in none of the cFDRA patients (p = 0.001). LOFA accounts for 17 % of Brazilian FDRA patients evaluated herein. Clinically, orthopedic features and spasticity with retained reflexes are helpful tips to differentiate LOFA from cFDRA patients.

Protective effect of antioxidants on DNA damage in leukocytes from X-linked adrenoleukodystrophy patients.

Toxic metabolites accumulation and oxidative stress have been associated to the pathophysiology of X-linked adrenoleukodystrophy (X-ALD), an inborn error of peroxisome metabolism. Parameters of oxidative damage to proteins and lipids in X-ALD patients were already described in literature; however, DNA injuries were not studied yet. Considering that, the aims were to investigate DNA damage by comet assay in heterozygotes and symptomatic X-ALD patients, to look for associations between DNA damage and lipid peroxidation as measured by urinary 15-F2t-isoprostane; and to evaluate the in vitro effect of N-acetyl-l-cysteine (NAC), trolox (TRO) and rosuvastatin (RSV) on DNA damage in leukocytes from symptomatic patients. Symptomatic patients presented higher DNA damage levels than those found in heterozygotes and controls; heterozygotes and controls showed similar results. In order to investigate the in vitro antioxidant effect on DNA damage, whole blood cells from symptomatic patients were incubated with NAC (1 and 2.5mM), TRO (25 and 75 µM) and RSV (0.5, 2 and 5 µM) before DNA damage analysis. NAC, TRO and RSV, at all tested concentrations, were all capable to reduce DNA damage in symptomatic X-ALD patients until control levels. Finally, DNA damage correlated with urinary isoprostanes and plasmatic levels of TBA-RS and DCFH-DA, allowing to hypothesize that DNA damage might be induced by lipid peroxidation in symptomatic patients. The present work yields experimental evidence that NAC, TRO and RSV reduce the in vitro DNA injury in symptomatic X-ALD patients, what may suggest that the administration of these antioxidants might be considered as an adjuvant therapy for X-ALD.

Clinical Scales Predict Significant Videofluoroscopic Dysphagia in Machado Joseph Disease Patients.

BACKGROUND: Although aspiration is one of the main causes of death in SCA, such as SCA3/Machado Joseph disease (SCA3/MJD), clinical studies on dysphagia are lacking for these diseases. The aims of this study were to characterize dysphagia in SCA3/MJD through videofluoroscopy (VF) of swallowing, correlate VF with disease severity criteria and weight loss, and determine the clinical criteria cutoffs for performing VF in the clinical routine, in order to detect aspiration. METHODS: A cross-sectional study on 34 SCA3/MJD patients was performed. Clinical and molecular data, as well as body mass index (BMI), were obtained. Neurological scales, such as the Scale for the Assessment and Rating of Ataxia (SARA), and the Swallowing Quality of Life (SWAL-QOL) questionnaire were applied. The VF scores, Dysphagia Outcome and Severity Scale (DOSS) and penetration/aspiration scale (PAS), were obtained: Moderate-to-severe scores were grouped as "significant dysphagia." RESULTS: Overall, 31 of 34 individuals showed abnormal scores at VF. SARA, BMI, and the domain "eating duration" of SWAL-QOL correlated with VF: Their relation to significant dysphagia (DOSS <4 points or PAS >3) was evaluated through receiver operating characteristic curves. A sensitivity of 100% was equivalent to a cutoff of 15 points on SARA score, 23.72 kg/m2 on BMI, and 60% on eating duration-SWAL-QOL (P < 0.05). CONCLUSION: Significant dysphagia was not related to age at onset, disease duration, or CAG repeat expansion, but with SARA scores, lower BMI, and the domain eating duration of SWAL-QOL. As a guideline for preventing aspiration, we suggest that SARA scores greater than 15 or eating duration-SWAL-QOL lower than 60% should urge VF studies in SCA3/MJD.

The effect of bone marrow transplantation on oxidative stress in X-linked adrenoleukodystrophy.

Oxidative stress plays an important role in the pathophysiology of neurodegenerative diseases, including X-linked adrenoleukodystrophy (X-ALD). In the present work, we evaluated lipid (malondialdehyde [MDA] content) and protein (sulfhydryl and carbonyl contents) oxidative damage parameters in plasma from X-ALD patients before and after bone marrow transplant (BMT), in order to verify if this treatment is capable to alter the oxidative parameters studied. We also evaluated the plasma concentration of hexacosanoic acid (C26:0) from X-ALD patients and correlated it with the oxidative damage parameters investigated. We observed that MDA content was significantly increased in plasma of X-ALD patients before BMT and after BMT when compared to controls, and that it was significantly reduced in plasma of X-ALD after BMT when compared to the before BMT group. These results indicate that lipid peroxidation is stimulated in X-ALD patients but there is a significant reduction of lipid peroxidation after BMT. Next, we observed a significant reduction of sulfhydryl content in plasma of X-ALD patients before BMT compared to controls indicating protein oxidative damage and that this measurement was increased in these patients after BMT as compared to before BMT. We found no significant differences in plasma carbonyl content in X-ALD patients before and after BMT as compared to controls. However, we observed a significant reduction in this parameter in X-ALD patients after BMT compared to before BMT. Finally, C26:0 plasma concentration was significantly reduced in X-ALD patients after BMT when compared to before BMT. We found no significant correlations between MDA and carbonyl values with C26:0 levels of the patients before BMT and after BMT, but a significant inverse correlation between sulfhydryl content and C26:0 levels was detected. In conclusion, the present study reinforces the hypothesis that lipid peroxidation and protein damage are induced in plasma of X-ALD patients and, in addition, demonstrates that BMT treatment is capable to reduce this pathogenic process. Taken together, the data obtained from plasma of X-ALD patients before and after BMT showing induction and protection, respectively, of oxidative stress, allowed to suggest that BMT, when well succeeded and under the recommendations, is effective to reduce C26:0 plasma levels and the increased lipid and protein oxidative damage in X-ALD.

Sequence analysis of 5' regulatory regions of the Machado-Joseph disease gene (ATXN3).

Machado-Joseph disease (MJD) is a late-onset autosomal dominant neurodegenerative disorder, which is caused by a coding (CAG)(n) expansion in the ATXN3 gene (14q32.1). The number of CAG repeats in the expanded alleles accounts only for 50 to 75 % of onset variance, the remaining variation being dependent on other factors. Differential allelic expression of ATXN3 could contribute to the explanation of different ages at onset in patients displaying similar CAG repeat sizes. Variation in 5' regulatory regions of the ATXN3 gene may have the potential to influence expression levels and, ultimately, modulate the MJD phenotype. The main goal of this work was to analyze the extent of sequence variation upstream of the ATXN3 start codon. A fragment containing the core promoter and the 5' untranslated region (UTR) was sequenced and analyzed in 186 patients and 59 controls (490 chromosomes). In the core promoter, no polymorphisms were observed. In the 5' UTR, only one SNP (rs3814834) was found, but no improvements on the explanation of onset variance were observed, when adding its allelic state in a linear model. Accordingly, in silico analysis predicted that this SNP lays in a nonconserved position for CMYB binding. Therefore, no functional effect could be predicted for this variant.