RESUMO
Untranslated regions are involved in the regulation of transcriptional and post-transcriptional processes. Characterization of these regions remains poorly explored for ATXN3, the causative gene of Machado-Joseph disease (MJD). Although a few genetic modifiers have been identified for MJD age at onset (AO), they only explain a small fraction of the AO variance. Our aim was to analyse variation at the 3'UTR of ATXN3 in MJD patients, analyse its impact on AO and attempt to build haplotypes that might discriminate between normal and expanded alleles.After assessing ATXN3 3'UTR variants in molecularly confirmed MJD patients, an in silico analysis was conducted to predict their functional impact (e.g. their effect on miRNA-binding sites). Alleles in cis with the expanded (CAG)n were inferred from family data, and haplotypes were built. The effect of the alternative alleles on the AO and on SARA and NESSCA ataxia scales was tested.Nine variants, all previously described, were found. For eight variants, in silico analyses predicted (a) deleterious effects (rs10151135; rs55966267); (b) changes on miRNA-binding sites (rs11628764; rs55966267; rs709930) and (c) alterations of RNA-binding protein (RBP)-binding sites (rs1055996; rs910369; rs709930; rs10151135; rs3092822; rs7158733). Patients harbouring the alternative allele at rs10151135 had significantly higher SARA Axial subscores (p = 0.023), comparatively with those homozygous for the reference allele. Ten different haplotypes were obtained, one of which was exclusively found in cis with the expanded and four with the normal allele. These findings, which are relevant for the design of allele-specific therapies, warrant further investigation in independent MJD cohorts.
Assuntos
Doença de Machado-Joseph , MicroRNAs , Humanos , Doença de Machado-Joseph/genética , Doença de Machado-Joseph/metabolismo , Ataxina-3/genética , Regiões 3' não Traduzidas/genética , MicroRNAs/genética , Variação Genética , Proteínas Repressoras/genéticaRESUMO
BACKGROUND: Biallelic pathogenic variants in AIMP1 gene cause hypomyelinating leukodystrophy type 3, a severe neurodegenerative disorder with early onset characterized by microcephaly, axial hypotonia, epilepsy, spasticity, and developmental delay. METHODS: Clinical exome sequence was performed on patient's DNA and Sanger sequencing was used to confirm the candidate variant. To better characterize the effect of the genetic variant, functional analysis based on Sanger sequencing of the proband's complementary DNA (cDNA) was performed. RESULTS: We report a case of 2-year-old girl with microcephaly, significant global developmental delay, refractory epilepsy, flaccid paralysis, hypomyelination, leukodystrophy, and cerebral atrophy on brain magnetic resonance imaging (MRI). Clinical exome sequencing revealed a novel splice site variant c.603 + 1G > A in homozygosity in the AIMP1 gene. Studies on patient's cDNA showed that the variant disrupts the canonical donor splice site of intron 5, with the recognition of a cryptic splice site within exon 5, leading to the skipping of the last 24 nucleotides of this exon together with the flanking intron. This alteration is predicted to cause an in-frame deletion of eight amino acids (p.Val194_Gln201del) belonging to the tRNA-biding domain of the protein. CONCLUSION: To the best of our knowledge, this is the first report of a splice site variant in the AIMP1 gene causing hypomyelinating leukodystrophy. The description of this patient not only expands the mutational spectrum of AIMP1 but also provides deeper insights on genotype-phenotype correlation by comparing the clinical features of our patient with previously reported affected individuals.
Assuntos
Microcefalia , Humanos , Microcefalia/genética , DNA Complementar , Mutação , Encéfalo/patologia , ExomaRESUMO
BACKGROUND: Progressive muscular atrophy (PMA) is a rare adult-onset neurological disease that is characterized by isolated lower motor neuron degeneration. While it is still disputable whether PMA is a subtype of amyotrophic lateral sclerosis (ALS) or an isolated disorder, it is well-established as a clinically defined entity. About 5% of PMA cases are monogenic, and the implicated genes largely overlap with those causing monogenic ALS. CASE DESCRIPTION: Here we describe a 68-year-old female patient with progressive and asymmetric upper-limb weakness throughout an 18-month period, with muscle atrophy, dysphagia and slurring of speech. The lower limbs were unaffected, and there was no sign of upper motor neuron dysfunction. Comprehensive genetic testing for single nucleotide and copy-number variants revealed a pathogenic monoallelic variant c.1529C>T, p.(Ala510Val) in the SPG7 gene. DISCUSSION: Pathogenic biallelic SPG7 variants have been originally associated with hereditary spastic paraplegia, but other phenotypes are nowadays known to be linked to these variants, such as ALS. However, there is no report of this (or any) other SPG7 variant in association with PMA, whether it progressed to ALS or not. In conclusion, we present the first known case of PMA associated with a monoallelic SPG7 mutation.
Assuntos
Esclerose Lateral Amiotrófica , Atrofia Muscular Espinal , Paraplegia Espástica Hereditária , Feminino , Humanos , Esclerose Lateral Amiotrófica/genética , Esclerose Lateral Amiotrófica/patologia , Atrofia Muscular Espinal/genética , Mutação/genética , Testes Genéticos , Paraplegia Espástica Hereditária/genética , ATPases Associadas a Diversas Atividades Celulares/genética , Metaloendopeptidases/genéticaRESUMO
BACKGROUND: In recent years, ambulatory lower limb exoskeletons are being gradually introduced into the clinical practice to complement walking rehabilitation programs. However, the clinical evidence of the outcomes attained with these devices is still limited and nonconclusive. Furthermore, the user-to-robot adaptation mechanisms responsible for functional improvement are still not adequately unveiled. This study aimed to (1) assess the safety and feasibility of using the HANK exoskeleton for walking rehabilitation, and (2) investigate the effects on walking function after a training program with it. METHODS: A randomized controlled trial was conducted including a cohort of 23 patients with less than 1 year since injury, neurological level of injury (C2-L4) and severity (American Spinal Cord Injury Association Impairment Scale [AIS] C or D). The intervention was comprised of 15 one-hour gait training sessions with lower limb exoskeleton HANK. Safety was assessed through monitoring of adverse events, and pain and fatigue through a Visual Analogue Scale. LEMS, WISCI-II, and SCIM-III scales were assessed, along with the 10MWT, 6MWT, and the TUG walking tests (see text for acronyms). RESULTS: No major adverse events were reported. Participants in the intervention group (IG) reported 1.8 cm (SD 1.0) for pain and 3.8 (SD 1.7) for fatigue using the VAS. Statistically significant differences were observed for the WISCI-II for both the "group" factor (F = 16.75, p < 0.001) and "group-time" interactions (F = 8.87; p < 0.01). A post-hoc analysis revealed a statistically significant increase of 3.54 points (SD 2.65, p < 0.0001) after intervention for the IG but not in the CG (0.7 points, SD 1.49, p = 0.285). No statistical differences were observed between groups for the remaining variables. CONCLUSIONS: The use of HANK exoskeleton in clinical settings is safe and well-tolerated by the patients. Patients receiving treatment with the exoskeleton improved their walking independence as measured by the WISCI-II after the treatment.
Assuntos
Exoesqueleto Energizado , Traumatismos da Medula Espinal , Humanos , Marcha , Caminhada , Traumatismos da Medula Espinal/reabilitação , Fadiga , DorRESUMO
A 9-year-old boy diagnosed with acute myeloblastic leukemia and undergoing chemotherapy, was admitted with febrile neutropenia. During his admission, several violaceous plaques appeared on the upper extremities and anterior left hemithorax, which worsened and acquired a necrotic center. We performed a biopsy and histology showed a cutaneous infarction at the dermoepidermal and subcutaneous level. We observed abundant wide hyphae with right-angled branching and a culture isolated Rhizopus oryzae. A plastic surgery consultant performed a surgical debridement of the lesions and treatment was started with intravenous amphotericin B. The patient did well on treatment and after almost a month of hospitalization, he was discharged with oral posaconazole. Mucormycosis is an opportunistic fungal infection associated with immunosuppression, particularly involving prematurity and hematological diseases in the pediatric age group. Multiple lesions, as in our case, are infrequent. The clinical presentation is variable. Direct smear or histological observation is the quickest diagnostic technique whereas culture is the most definitive. The combination of surgical debridement and amphotericin B is the treatment with the highest survival rates.
Assuntos
Anfotericina B , Mucormicose , Masculino , Humanos , Criança , Anfotericina B/uso terapêutico , Rhizopus , Mucormicose/diagnóstico , Mucormicose/terapia , Pele/patologia , Necrose/complicações , Antifúngicos/uso terapêuticoRESUMO
Machado-Joseph disease (MJD/SCA3) is a neurodegenerative polyglutamine disorder exhibiting a wide spectrum of phenotypes. The abnormal size of the (CAG)n at ATXN3 explains ~55% of the age at onset variance, suggesting the involvement of other factors, namely genetic modifiers, whose identification remains limited. Our aim was to find novel genetic modifiers, analyse their epistatic effects and identify disease-modifying pathways contributing to MJD variable expressivity. We performed whole-exome sequencing in a discovery sample of four age at onset concordant and four discordant first-degree relative pairs of Azorean patients, to identify candidate variants which genotypes differed for each discordant pair but were shared in each concordant pair. Variants identified by this approach were then tested in an independent multi-origin cohort of 282 MJD patients. Whole-exome sequencing identified 233 candidate variants, from which 82 variants in 53 genes were prioritized for downstream analysis. Eighteen disease-modifying pathways were identified; two of the most enriched pathways were relevant for the nervous system, namely the neuregulin signaling and the agrin interactions at neuromuscular junction. Variants at PARD3, NFKB1, CHD5, ACTG1, CFAP57, DLGAP2, ITGB1, DIDO1 and CERS4 modulate age at onset in MJD, with those identified in CFAP57, ACTG1 and DIDO1 showing consistent effects across cohorts of different geographical origins. Network analyses of the nine novel MJD modifiers highlighted several important molecular interactions, including genes/proteins previously related with MJD pathogenesis, namely between ACTG1/APOE and VCP/ITGB1. We describe novel pathways, modifiers, and their interaction partners, providing a broad molecular portrait of age at onset modulation to be further exploited as new disease-modifying targets for MJD and related diseases.
Assuntos
Doença de Machado-Joseph , Idade de Início , Alelos , DNA Helicases/genética , Genótipo , Humanos , Doença de Machado-Joseph/genética , Doença de Machado-Joseph/patologia , Proteínas do Tecido Nervoso/genética , Sequenciamento do ExomaRESUMO
BACKGROUND: Ataxia with oculomotor apraxia (AOA) is characterized by early-onset cerebellar ataxia associated with oculomotor apraxia. AOA1, AOA2, AOA3, and AOA4 subtypes may present pathogenic variants in APTX, SETX, PIK3R5, and PNKP genes, respectively. Mutations in XRCC1 have been found to cause autosomal recessive spinocerebellar ataxia-26 (SCAR26) now considered AOA5. OBJECTIVES: To examine a cohort of Brazilians with autosomal recessive cerebellar ataxia plus oculomotor apraxia and determine the frequencies of AOA subtypes through genetic investigation. METHODS: We evaluated clinical, biomarkers, electrophysiological, and radiological findings of 52 patients with AOA phenotype and performed a genetic panel including APTX, SETX, PIK3R5, PNKP, and XRCC1. RESULTS: We found pathogenic variants in SETX (15 patients), PNKP (12), and APTX (5). No mutations in PIK3R5 or XRCC1 were identified. CONCLUSIONS: AOA2 and AOA4 were the most common forms of AOA in Brazil. Mutations in PIK3R5 and XRCC1 were not part of this genetic spectrum. © 2022 International Parkinson and Movement Disorder Society.
Assuntos
Apraxias , Ataxia Cerebelar , Apraxias/congênito , Apraxias/genética , Ataxia/genética , Brasil , Ataxia Cerebelar/complicações , Ataxia Cerebelar/genética , Síndrome de Cogan , DNA Helicases/genética , Enzimas Reparadoras do DNA/genética , Humanos , Enzimas Multifuncionais/genética , Mutação/genética , Fosfotransferases (Aceptor do Grupo Álcool)/genética , RNA Helicases/genética , Proteína 1 Complementadora Cruzada de Reparo de Raio-X/genéticaRESUMO
Spastic ataxias are rare neurogenetic disorders involving spinocerebellar and pyramidal tracts. Many genes are involved. Among them, CAPN1, when mutated, is responsible for a complex inherited form of spastic paraplegia (SPG76). We report the largest published series of 21 novel patients with nine new CAPN1 disease-causing variants and their clinical characteristics from two European university hospitals (Paris and Stockholm). After a formal clinical examination, causative variants were identified by next-generation sequencing and confirmed by Sanger sequencing. CAPN1 variants are a rare cause (~ 1.4%) of young-adult-onset spastic ataxia; however, together with all published cases, they allowed us to better describe the clinical and genetic spectra of this form. Truncating variants are the most frequent, and missense variants lead to earlier age at onset in favor of an additional deleterious effect. Cerebellar ataxia with cerebellar atrophy, dysarthria and lower limb weakness are often associated with spasticity. We also suggest that cognitive impairment and depression should be assessed specifically in the follow-up of SPG76 cases.
Assuntos
Calpaína/genética , Deficiência Intelectual/genética , Espasticidade Muscular/genética , Mutação/genética , Atrofia Óptica/genética , Paraplegia Espástica Hereditária/genética , Ataxias Espinocerebelares/genética , Adulto , Idade de Início , Ataxia Cerebelar/genética , Criança , Feminino , Estudos de Associação Genética , Humanos , Deficiência Intelectual/diagnóstico , Masculino , Espasticidade Muscular/diagnóstico , Atrofia Óptica/diagnóstico , Linhagem , Fenótipo , Ataxias Espinocerebelares/diagnóstico , Adulto JovemRESUMO
BACKGROUND: Freezing is considered the most suitable technological treatment to avoid Anisakis infection from eating raw or undercooked fish but modifications of their cuticles upon freezing may reduce their resistance to gastric fluids, provoking a greater release of allergens. This work aimed to study the relationship between freezing-induced modifications of Anisakis simplex s.l., antigen recognition, and resistance to oral and gastric digestion in spiked fish mince. RESULTS: (i) Differences between non-treated larvae and larvae that survived freezing / thawing were studied in terms of respiratory capacity, survival in simulated gastric fluid (SGF), recognition of antigens and allergens. (ii) Untreated (i.e. chilled) mince containing live larvae, mince frozen at two freezing rates, with a negative (uninfected) mince and a positive mince (infected with broken larvae) as controls, were subjected to the oral and gastric phases of a simulated digestion process. Anisakis able to survive freezing showed lower resistance to gastric fluid (i.e. faster mortality as compared to controls). Untreated larvae released significantly more antigens than freeze-surviving larvae but only after 96 h in SGF. In treatments rendering complete larvae mortality, the highest loss of larvae integrity was found upon fast freezing. There was a positive correlation between antigen release and the number of ruptures of larvae after the oral digestion phase, whereas a more complex trend was observed after oral plus gastric digestion phases. CONCLUSION: These results suggest a new factor to consider for sensitized patients and suggest that the numbers of L3 should be reduced before industrial freezing to minimize risk. © 2020 Society of Chemical Industry.
Assuntos
Anisaquíase/metabolismo , Anisakis/metabolismo , Antígenos de Helmintos/metabolismo , Contaminação de Alimentos/análise , Gadiformes/parasitologia , Suco Gástrico/enzimologia , Animais , Anisaquíase/parasitologia , Anisakis/classificação , Anisakis/genética , Anisakis/imunologia , Antígenos de Helmintos/análise , Manipulação de Alimentos , Congelamento , Humanos , Larva/classificação , Larva/genética , Larva/imunologia , Larva/metabolismo , Modelos BiológicosRESUMO
BACKGROUND: Migraine is a multifactorial disorder that is more frequent (two to four times) in women than in men. In recent years, our research group has focused on the role of neurotransmitter release and its regulation. Neurexin (NRXN2) is one of the components of the synaptic vesicle machinery, responsible for connecting intracellular fusion proteins and synaptic vesicles. Our aim was to continue exploring the role and interaction of proteins involved in the control and promotion of neurotransmission in migraine susceptibility. METHODS: A case-control study was performed comprising 183 migraineurs (148 females and 35 males) and 265 migraine-free controls (202 females and 63 males). Tagging single nucleotide polymorphisms of NRXN2 were genotyped to assess the association between NRXN2 and migraine susceptibility. The χ2 test was used to compare allele frequencies in cases and controls and odds ratios were estimated with 95% confidence intervals. Haplotype frequencies were compared between groups. Gene-gene interactions were analysed using the Multifactor Dimensionality Reduction v2.0. RESULTS: We found a statistically significant interaction model (p = 0.009) in the female group between the genotypes CG of rs477138 (NRXN2) and CT of rs1158605 (GABRE). This interaction was validated by logistic regression, showing a significant risk effect [OR = 4.78 (95%CI: 1.76-12.97)] after a Bonferroni correction. Our data also supports a statistically significant interaction model (p = 0.011) in the female group between the GG of rs477138 in NRXN2 and, the rs2244325's GG genotype and rs2998250's CC genotype of CASK. This interaction was also validated by logistic regression, with a protective effect [OR = 0.08 (95%CI: 0.01-0.75)]. A weak interaction model was found between NRXN2-SYT1. We have not found any statistically significant allelic or haplotypic associations between NRXN2 and migraine susceptibility. CONCLUSIONS: This study unravels, for the first time, the gene-gene interactions between NRXN2, GABRE - a GABAA-receptor - and CASK, importantly it shows the synergetic effect between those genes and its relation with migraine susceptibility. These gene interactions, which may be a part of a larger network, can potentially help us in better understanding migraine aetiology and in development of new therapeutic approaches.
Assuntos
Predisposição Genética para Doença , Transtornos de Enxaqueca , Proteínas do Tecido Nervoso/genética , Estudos de Casos e Controles , Feminino , Frequência do Gene , Genótipo , Guanilato Quinases/genética , Humanos , Masculino , Transtornos de Enxaqueca/genética , Polimorfismo de Nucleotídeo Único , Receptores de GABA-A/genética , Sinaptotagmina I/genéticaRESUMO
OBJECTIVE: Transthyretin (TTR)-related familial amyloid polyneuropathy (FAP) is an autosomal dominant neurological disease, caused most frequently by a Val30Met (now classified as Val50Met) substitution in TTR. Age at onset (AO) ranges from 19 to 82 years, and variability exists mostly between generations. Unstable oligonucleotide repeats in various genes are the mechanism behind several neurological diseases, found also to act as modifiers for other disorders. Our aim was to investigate whether large normal repeat alleles of 10 genes had a possible modifier effect in AO in Portuguese TTR-FAP Val30Met families. METHODS: We analyzed 329 Portuguese patients from 123 families. Repeat length (at ATXN1, ATXN2, ATXN3, ATXN7, TBP, ATN1, HTT, JPH3, AR, and DMPK) was assessed by single and multiplex polymerase chain reaction, using fluorescently labeled primers, followed by capillary electrophoresis. We used a family-centered approach, and generalized estimating equations were used to account for AO correlation between family members. RESULTS: For ATXN2, the presence of at least 1 allele longer than 22 CAGs was significantly associated with an earlier onset in TTR-FAP Val30Met, decreasing mean AO by 6 years (95% confidence interval = -8.81 to -2.19, p = 0.001). No association was found for the remaining repeat loci. INTERPRETATION: Length of normal repeats at ATXN2 may modify AO in TTR-FAP Val30Met and may function as a risk factor. This can be due to the role of ATXN2 in RNA metabolism and as a modulator of various cellular processes, including mitochondrial stress. This may have relevant implications for prognosis and the follow-up of presymptomatic carriers. ANN NEUROL 2019;85:251-258.
Assuntos
Neuropatias Amiloides Familiares/genética , Ataxina-2/genética , Pré-Albumina/genética , Expansão das Repetições de Trinucleotídeos/genética , Adulto , Idade de Início , Doenças Assintomáticas , Feminino , Genes Modificadores , Humanos , Masculino , Pessoa de Meia-Idade , Portugal , Prognóstico , População Branca/genética , Adulto JovemRESUMO
OBJECTIVE: A number of observations, including among our study population, have implicated variants in the syntaxin-1A, a component of the synaptic vesicles, in migraine susceptibility. Therefore, we hypothesize that variants in other components of the vesicle machinery are involved in migraine. BACKGROUND: Migraine is a common and complex neurologic disorder that affects approximately 15-18% of the general population. The exact cause of migraine is unknown; however, genetic studies have made possible substantial progress toward the identification of underlying molecular pathways. Neurotransmitters have been for long considered to have a key role in migraine pathophysiology; so we investigated common variants in genes involved in the synaptic vesicle machinery and their impact in migraine susceptibility. METHODS: We performed a case-control study comprising 188 unrelated patients with headache and 286 healthy controls in a population from the north of Portugal. Benefiting from the presence of linkage disequilibrium, we selected and genotyped 119 tagging single-nucleotide polymorphisms in 18 genes. RESULTS: We found significant associations between single-nucleotide variants and migraine in 7 genes, SYN1, SYN2, SNAP25, VAMP2, STXBP1, STXBP5, and UNC13A, either conferring an increased risk or protection of migraine. Due to SYN1 X-chromosomal location, we performed the statistical analysis separated by gender and, in the female group, the C allele of rs5906435 increased the risk for migraine susceptibility (P = .021; OR = 1.69; 95% CI: 1.21-2.34). In contrast, the TT genotype of the same variant emerged as a potential protective factor (P = .003; OR = 0.45; 95% CI: 0.27-0.74). The SYN2 analysis supported the rs3773364's G allele (P = .014) as a risk factor for migraine, and although not statistically significant after correction, the AG genotype (P = .006; OR = 1.86; 95% CI: 1.20-2.90) reinforced the allelic findings. Additionally, we found the SNAP25-rs363039's CT genotype (P = .001; OR = 2.14; 95% CI: 1.36-3.34), the STXBP5-rs1765028's T allele (P = .041; OR = 1.46; 95% CI: 1.13-1.90), and the UNC13B-rs7851161's TT genotype (P = .001; OR = 2.14; 95% CI: 1.36-3.34) as statistically significant risk factors for migraine liability. VAMP2-rs1150's G allele revealed a risk association to migraine, not statistically significant after correction (P = .068). Additionally, we found haplotypes in SYN1, SYN2, STXBP1, and UNC13B to be associated with migraine. CONCLUSIONS: Overall, this study provides a new insight into migraine liability, identifying possible starting points for functional studies.
Assuntos
Transtornos de Enxaqueca/genética , Vesículas Sinápticas/genética , Adulto , Estudos de Casos e Controles , Feminino , Humanos , Desequilíbrio de Ligação , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , PortugalRESUMO
Human infection due to eating fish parasitized by live Anisakis larvae in the third stage is considered an important health problem, and the application of treatments to ensure their mortality in the fish products is crucial to prevent the risk of infection. Mobility is used to assess viability, but mobile larvae may not always be infective and immobile larvae may be erroneously considered as non-viable. The objective was to establish whether the analysis of respiratory activity by means of the oxygen consumption rate (OCR) of Anisakis could be used to identify subtle differences between larvae that were still considered viable in terms of their mobility but had been subjected to thermal and/or chemical stress. The metabolic modulators FCCP [carbonyl cyanide 4-(trifluoromethoxy) phenylhydrazone] and sodium azide were used and the basal, maximum, spare and residual respiration rates calculated. Results showed that maximum respiratory capacity of larvae subjected to freezing significantly decreased immediately after thawing, but after some acclimatization, they recovered their capacity fully. However, when these larvae were stored at 4.6 °C, their mitochondria became dysfunctional faster than those of untreated larvae. OCR also showed that mitochondria of larvae were affected by incubation at 37 °C in NaCl or gastric juice. To conclude, OCR of Anisakis in the presence of metabolic modulators can help to identify subtle changes that occur in the larva. These measurements could be used to characterize larvae subjected to various stresses so that a broader picture of Anisakis pathogenic potential can be gained.
Assuntos
Anisakis/metabolismo , Carbonil Cianeto p-Trifluormetoxifenil Hidrazona/farmacologia , Inibidores Enzimáticos/farmacologia , Larva/metabolismo , Mitocôndrias/metabolismo , Consumo de Oxigênio/fisiologia , Azida Sódica/farmacologia , Aclimatação/fisiologia , Animais , Anisaquíase/veterinária , Anisakis/embriologia , Doenças dos Peixes/parasitologia , Peixes/parasitologia , Humanos , Alimentos Marinhos/parasitologia , Cloreto de Sódio/farmacologiaRESUMO
Hereditary autosomal-recessive cerebellar ataxias are a genetically and clinically heterogeneous group of disorders. We used homozygosity mapping and exome sequencing to study a cohort of nine Portuguese families who were identified during a nationwide, population-based, systematic survey as displaying a consistent phenotype of recessive ataxia with oculomotor apraxia (AOA). The integration of data from these analyses led to the identification of the same homozygous PNKP (polynucleotide kinase 3'-phosphatase) mutation, c.1123G>T (p.Gly375Trp), in three of the studied families. When analyzing this particular gene in the exome sequencing data from the remaining cohort, we identified homozygous or compound-heterozygous mutations in five other families. PNKP is a dual-function enzyme with a key role in different pathways of DNA-damage repair. Mutations in this gene have previously been associated with an autosomal-recessive syndrome characterized by microcephaly; early-onset, intractable seizures; and developmental delay (MCSZ). The finding of PNKP mutations associated with recessive AOA extends the phenotype associated with this gene and identifies a fourth locus that causes AOA. These data confirm that MCSZ and some forms of ataxia share etiological features, most likely reflecting the role of PNKP in DNA-repair mechanisms.
Assuntos
Síndrome de Cogan/genética , Enzimas Reparadoras do DNA/genética , Fosfotransferases (Aceptor do Grupo Álcool)/genética , Degenerações Espinocerebelares/genética , Apraxias/congênito , Criança , Pré-Escolar , Dano ao DNA , Reparo do DNA , Enzimas Reparadoras do DNA/metabolismo , Feminino , Heterozigoto , Homozigoto , Humanos , Lactente , Masculino , Microcefalia/genética , Mutação , Linhagem , Fenótipo , Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo , Ataxias Espinocerebelares/congênitoRESUMO
BACKGROUND: Transthyretin-related familial amyloid polyneuropathy (TTR-FAP Val30Met) shows a wide variation in age-at-onset (AO) between generations and genders, as in Portuguese families, where women display a later onset and a larger anticipation (>10 years). Mitochondrial DNA (mtDNA) copy number was assessed to clarify whether it has a modifier effect on AO variability in Portuguese patients. METHODS: The mtDNA copy number of 262 samples (175 Val30Met TTR carriers and 87 controls (proven Val30Val)) was quantified by quantitative real-time PCR. Statistical analysis was performed using IBM SPSS V.23 software. RESULTS: This study shows that Val30Met TTR carriers have a significantly higher (p<0.001) mean mtDNA copy number than controls. Furthermore, the highest mtDNA copy number mean was observed in early-onset patients (AO <40 years). Importantly, early-onset offspring showed a significant increase (p=0.002) in the mtDNA copy number, when compared with their late AO parents. CONCLUSIONS: The present findings suggest, for the first time, that mtDNA copy number may be associated with earlier events and may therefore be further explored as a potential biomarker for follow-up of TTR-FAP Val30Met carriers.
Assuntos
Neuropatias Amiloides Familiares/genética , Variações do Número de Cópias de DNA/genética , DNA Mitocondrial/genética , Pré-Albumina/genética , Adolescente , Adulto , Idade de Início , Idoso , Idoso de 80 Anos ou mais , Antecipação Genética , Doenças Assintomáticas , Estudos de Casos e Controles , Feminino , Heterozigoto , Humanos , Masculino , Pessoa de Meia-Idade , Mutação , Reação em Cadeia da Polimerase em Tempo Real , Fatores Sexuais , Adulto JovemRESUMO
The expansion in the C9orf72 gene has been recently reported as a genetic cause of Huntington's disease (HD) phenocopies. We aim to assess the frequency of the C9orf72 gene expansion in a Portuguese HD phenocopies cohort. Twenty HD phenotype-like patients without diagnosis were identified in our institutional database. C9orf72 gene expansion was detected using repeat-primed PCR. Clinical files were reviewed to characterize the phenotype of expansion-positive cases. One patient (5%) was positive for the C9orf72 expansion. A second patient presented 27 repeats-within the intermediate size interval. Both had familial neuropsychiatric disease characterized by diverse movement disorders, dementia, and psychiatric dysfunction that was distinct in severity and clinical expression. C9orf72 disease is clinically heterogeneous and without evident imaging markers. The definition of the role of intermediate alleles and of the pathological threshold for C9orf72 repeat expansions may have diagnostic implications.
Assuntos
Proteína C9orf72/genética , Doença de Huntington/genética , Idoso , Alelos , Esclerose Lateral Amiotrófica/genética , Estudos de Coortes , Expansão das Repetições de DNA/genética , Feminino , Humanos , Masculino , FenótipoRESUMO
Mutations in DJ-1 (encoded by PARK7) are a very rare cause of early-onset recessive Parkinson's disease. We describe a patient with early-onset parkinsonism, starting at the age of 22, with poor response to levodopa and additional features in progression (dystonia, pyramidal signs and dementia), who died when he was 49 years old. The neuropathological study showed severe substantia nigra and locus coeruleus neuronal loss, with diffuse Lewy body pathology (Lewy bodies, aberrant neurites, grain-like structures, spheroids and scattered glial pathology). Genetic analysis revealed a novel c.515T > A; p.L172Q mutation in the PARK7 gene. To evaluate the pathogenicity of this new mutation we explored DJ-1 expression levels in vitro showing a massive reduction in DJ-1 protein levels due to a highly unstable and rapidly degraded L172Q mutant. DJ-1 immunohistochemistry of brain tissue revealed no staining in our case. This is the first neuropathological report of a brain from DJ-1-linked parkinsonism that, although based on a single case study, suggests that DJ-1 mutations are causative of α-synucleinopathy. These results can help in the understanding of Parkinson's disease pathophysiology, promote research studies to increase the knowledge on the pathways involved in the neurodegeneration process, and pave the way for new therapeutic interventions.
Assuntos
Corpos de Lewy/patologia , Locus Cerúleo/patologia , Doença de Parkinson/genética , Doença de Parkinson/patologia , Proteína Desglicase DJ-1/genética , Substância Negra/patologia , Encéfalo/metabolismo , Encéfalo/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Mutação , Degeneração Neural/complicações , Degeneração Neural/patologia , Proteína Desglicase DJ-1/biossínteseRESUMO
More than 600 human disorders afflict the nervous system. Of these, neurodegenerative diseases are usually characterised by onset in late adulthood, progressive clinical course, and neuronal loss with regional specificity in the central nervous system. They include Alzheimer's disease and other less frequent dementias, brain cancer, degenerative nerve diseases, encephalitis, epilepsy, genetic brain disorders, head and brain malformations, hydrocephalus, stroke, Parkinson's disease, multiple sclerosis, amyotrophic lateral sclerosis (ALS or Lou Gehrig's Disease), Huntington's disease, and Prion diseases, among others. Neurodegeneration usually affects, but is not limited to, the cerebral cortex, intracranial white matter, basal ganglia, thalamus, hypothalamus, brain stem, and cerebellum. Although the majority of neurodegenerative diseases are sporadic, Mendelian inheritance is well documented. Intriguingly, the clinical presentations and neuropathological findings in inherited neurodegenerative forms are often indistinguishable from those of sporadic cases, suggesting that converging genomic signatures and pathophysiologic mechanisms underlie both hereditary and sporadic neurodegenerative diseases. Unfortunately, effective therapies for these diseases are scarce to non-existent. In this chapter, we highlight the clinical and genetic features associated with the rare inherited forms of neurodegenerative diseases, including ataxias, multiple system atrophy, spastic paraplegias, Parkinson's disease, dementias, motor neuron diseases, and rare metabolic disorders.
Assuntos
Genômica/métodos , Mutação , Doenças Neurodegenerativas/genética , Doenças Raras/genética , Análise Mutacional de DNA , Marcadores Genéticos , Predisposição Genética para Doença , Hereditariedade , Humanos , Doenças Neurodegenerativas/diagnóstico , Doenças Neurodegenerativas/epidemiologia , Doenças Neurodegenerativas/terapia , Fenótipo , Valor Preditivo dos Testes , Prognóstico , Doenças Raras/diagnóstico , Doenças Raras/epidemiologia , Doenças Raras/terapia , Fatores de RiscoRESUMO
A general overview, focusing on new trends in the different techniques used in restructured seafood product processing has been described in this work. Heat-induced gelation has been more widely studied in scientific literature than cold gelation technology. This latter technology includes the use of hydrocolloids (alginates and glucomannan) or enzymes (microbial transglutaminase) for making both raw and cooked restructured products. In restructuration processes, fortification processing with some functional ingredients is studied, giving as a result extra value to the products as well as increasing the variety of new seafood products. The process of alleviating heavy metals and organic pollutants from the raw material used has also been reviewed in the present paper.