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1.
J Med Genet ; 60(10): 965-973, 2023 10.
Article in English | MEDLINE | ID: mdl-37197784

ABSTRACT

BACKGROUND: Limb-girdle muscular dystrophies (LGMD) are a heterogeneous group of genetically determined muscle disorders. TRAPPC11-related LGMD is an autosomal-recessive condition characterised by muscle weakness and intellectual disability. METHODS: A clinical and histopathological characterisation of 25 Roma individuals with LGMD R18 caused by the homozygous TRAPPC11 c.1287+5G>A variant is reported. Functional effects of the variant on mitochondrial function were investigated. RESULTS: The c.1287+5G>A variant leads to a phenotype characterised by early onset muscle weakness, movement disorder, intellectual disability and elevated serum creatine kinase, which is similar to other series. As novel clinical findings, we found that microcephaly is almost universal and that infections in the first years of life seem to act as triggers for a psychomotor regression and onset of seizures in several individuals with TRAPPC11 variants, who showed pseudometabolic crises triggered by infections. Our functional studies expanded the role of TRAPPC11 deficiency in mitochondrial function, as a decreased mitochondrial ATP production capacity and alterations in the mitochondrial network architecture were detected. CONCLUSION: We provide a comprehensive phenotypic characterisation of the pathogenic variant TRAPPC11 c.1287+5G>A, which is founder in the Roma population. Our observations indicate that some typical features of golgipathies, such as microcephaly and clinical decompensation associated with infections, are prevalent in individuals with LGMD R18.


Subject(s)
Intellectual Disability , Microcephaly , Muscular Dystrophies, Limb-Girdle , Muscular Dystrophies , Roma , Humans , Roma/genetics , Phenotype , Muscular Dystrophies, Limb-Girdle/genetics , Muscle Weakness , Vesicular Transport Proteins
2.
Eur J Neurol ; 30(1): 215-223, 2023 01.
Article in English | MEDLINE | ID: mdl-36256504

ABSTRACT

BACKGROUND AND PURPOSE: Myotonic dystrophy type 1 (DM1) is a hereditary and multisystemic disease that is characterized by heterogeneous manifestations. Although muscular impairment is central to DM1, a premanifest DM1 form has been proposed for those characterized by the absence of muscle signs in precursory phases. Nevertheless, subtle signs and/or symptoms related to other systems, such as the central nervous system (CNS), may emerge and progress gradually. This study aimed to validate the premanifest DM1 concept and to characterize and track affected individuals from a CNS centred perspective. METHODS: Retrospective data of 120 participants (23 premanifest DM1, 25 manifest DM1 and 72 healthy controls) were analysed transversally and longitudinally (over 11.17 years). Compiled data included clinical, neuropsychological and neuroradiological (brain volume and white matter lesion, WML) measures taken at two time points. RESULTS: Manifest DM1 showed significantly more molecular affectation, worse performance on neuropsychological domains, lower grey and white matter volumes and a different pattern of WMLs than premanifest DM1. The latter was slightly different from healthy controls regarding brain volume and WMLs. Additionally, daytime sleepiness and molecular expansion size explained 50% of the variance of the muscular deterioration at follow-up in premanifest individuals. CONCLUSIONS: Premanifest DM1 individuals showed subtle neuroradiological alterations, which suggests CNS involvement early in the disease. Based on follow-up data, a debate emerges around the existence of a 'non-muscular DM1' subtype and/or a premanifest phase, as a precursory stage to other DM1 manifestations.


Subject(s)
Myotonic Dystrophy , White Matter , Humans , Myotonic Dystrophy/psychology , Follow-Up Studies , Retrospective Studies , White Matter/pathology
3.
JCI Insight ; 7(19)2022 10 10.
Article in English | MEDLINE | ID: mdl-36040809

ABSTRACT

Myotonic dystrophy type 1 (DM1; MIM #160900) is an autosomal dominant disorder, clinically characterized by progressive muscular weakness and multisystem degeneration. The broad phenotypes observed in patients with DM1 resemble the appearance of an accelerated aging process. However, the molecular mechanisms underlying these phenotypes remain largely unknown. Transcriptomic analysis of fibroblasts derived from patients with DM1 and healthy individuals revealed a decrease in cell cycle activity, cell division, and DNA damage response in DM1, all of which related to the accumulation of cellular senescence. The data from transcriptome analyses were corroborated in human myoblasts and blood samples, as well as in mouse and Drosophila models of the disease. Serial passage studies in vitro confirmed the accelerated increase in senescence and the acquisition of a senescence-associated secretory phenotype in DM1 fibroblasts, whereas the DM1 Drosophila model showed reduced longevity and impaired locomotor activity. Moreover, functional studies highlighted the impact of BMI1 and downstream p16INK4A/RB and ARF/p53/p21CIP pathways in DM1-associated cellular phenotypes. Importantly, treatment with the senolytic compounds Quercetin, Dasatinib, or Navitoclax reversed the accelerated aging phenotypes in both DM1 fibroblasts in vitro and in Drosophila in vivo. Our results identify the accumulation of senescence as part of DM1 pathophysiology and, therefore, demonstrate the efficacy of senolytic compounds in the preclinical setting.


Subject(s)
Myotonic Dystrophy , Animals , Dasatinib , Drosophila , Humans , Mice , Myotonic Dystrophy/genetics , Quercetin , Senotherapeutics , Tumor Suppressor Protein p53
4.
Sci Rep ; 12(1): 3988, 2022 03 07.
Article in English | MEDLINE | ID: mdl-35256728

ABSTRACT

Myotonic Dystrophy Type 1 (DM1) is a multisystemic disease that affects gray and white matter (WM) tissues. WM changes in DM1 include increased hyperintensities and altered tract integrity distributed in a widespread manner. However, the precise temporal and spatial progression of the changes are yet undetermined. MRI data were acquired from 8 adult- and late-onset DM1 patients and 10 healthy controls (HC) at two different timepoints over 9.06 years. Fractional anisotropy (FA) and mean diffusivity (MD) variations were assessed with Tract-Based Spatial Statistics. Transversal and longitudinal intra- and intergroup analyses were conducted, along with correlation analyses with clinical and neuropsychological data. At baseline, reduced FA and increased MD values were found in patients in the uncinate, anterior-thalamic, fronto-occipital, and longitudinal tracts. At follow-up, the WM disconnection was shown to have spread from the frontal part to the rest of the tracts in the brain. Furthermore, WM lesion burden was negatively correlated with FA values, while visuo-construction and intellectual functioning were positively correlated with global and regional FA values at follow-up. DM1 patients showed a pronounced WM integrity loss over time compared to HC, with a neurodegeneration pattern that suggests a progressive anterior-posterior disconnection. The visuo-construction domain stands out as the most sensitive neuropsychological measure for WM microstructural impairment.


Subject(s)
Myotonic Dystrophy , White Matter , Adult , Anisotropy , Brain/diagnostic imaging , Brain/pathology , Diffusion Tensor Imaging , Follow-Up Studies , Humans , Myotonic Dystrophy/diagnostic imaging , Myotonic Dystrophy/pathology , Neuropsychological Tests , White Matter/diagnostic imaging , White Matter/pathology
5.
J Stroke Cerebrovasc Dis ; 30(12): 106130, 2021 Dec.
Article in English | MEDLINE | ID: mdl-34597987

ABSTRACT

Cerebral cavernous malformations (CCMs) are dilated aberrant leaky capillaries located in the Central Nervous System. Familial CCM is an autosomal dominant inherited disorder related to mutations in KRIT1, Malcavernin or PDCD10. We show two unrelated families presenting familial CCM due to two new mutations in KRIT1 and PDCD10, producing truncated proteins. Clinical phenotype was highly variable among patients from asymptomatic individuals to diplopia, seizures or severe intracranial hemorrhage. PDCD10 patients usually show a more aggressive course and they frequently showed multiple meningiomas. This work provides evidence for the pathogenicity of two new mutations in CCM genes and supports previous findings regarding familial CCM and multiple meningiomas.


Subject(s)
Hemangioma, Cavernous, Central Nervous System , Mutation , Apoptosis Regulatory Proteins/genetics , Hemangioma, Cavernous, Central Nervous System/genetics , Humans , KRIT1 Protein/genetics , Membrane Proteins/genetics , Meningioma/genetics , Mutation/genetics , Proto-Oncogene Proteins/genetics
6.
Aging (Albany NY) ; 12(17): 16690-16708, 2020 Sep 09.
Article in English | MEDLINE | ID: mdl-32903216

ABSTRACT

The research of new biomarkers for Parkinson's disease is essential for accurate and precocious diagnosis, as well as for the discovery of new potential disease mechanisms and drug targets. The main objective of this work was to identify metabolic changes that might serve as biomarkers for the diagnosis of this neurodegenerative disorder. For this, we profiled the plasma metabolome from mice with neurotoxin-induced Parkinson's disease as well as from patients with familial or sporadic Parkinson's disease. By using mass spectrometry technology, we analyzed the complete metabolome from healthy volunteers compared to patients with idiopathic or familial (carrying the G2019S or R1441G mutations in the LRRK2 gene) Parkinson's disease, as well as, from mice treated with 6-hydroxydopamine to induce Parkinson disease. Both human and murine Parkinson was accompanied by an increase in plasma levels of unconjugated bile acids (cholic acid, deoxycholic acid and lithocholic acid) and purine base intermediary metabolites, in particular hypoxanthine. The comprehensive metabolomic analysis of plasma from Parkinsonian patients underscores the importance of bile acids and purine metabolism in the pathophysiology of this disease. Therefore, plasma measurements of certain metabolites related to these pathways might contribute to the diagnosis of Parkinson's Disease.

7.
Ann Clin Transl Neurol ; 7(10): 1802-1815, 2020 10.
Article in English | MEDLINE | ID: mdl-32881379

ABSTRACT

OBJECTIVE: To characterize the progression of brain structural abnormalities in adults with pediatric and adult/late onset DM1, as well as to examine the potential predictive markers of such progression. METHODS: 21 DM1 patients (pediatric onset: N = 9; adult/late onset: N = 12) and 18 healthy controls (HC) were assessed longitudinally over 9.17 years through brain MRI. Additionally, patients underwent neuropsychological, genetic, and muscular impairment assessment. Inter-group comparisons of total and voxel-level regional brain volume were conducted through Voxel Based Morphometry (VBM); cross-sectionally and longitudinally, analyzing the associations between brain changes and demographic, clinical, and cognitive outcomes. RESULTS: The percentage of GM loss did not significantly differ in any of the groups compared with HC and when assessed independently, adult/late DM1 patients and their HC group suffered a significant loss in WM volume. Regional VBM analyses revealed subcortical GM damage in both DM1 groups, evolving to frontal regions in the pediatric onset patients. Muscular impairment and the outcomes of certain neuropsychological tests were significantly associated with follow-up GM damage, while visuoconstruction, attention, and executive function tests showed sensitivity to WM degeneration over time. INTERPRETATION: Distinct patterns of brain atrophy and its progression over time in pediatric and adult/late onset DM1 patients are suggested. Results indicate a possible neurodevelopmental origin of the brain abnormalities in DM1, along with the possible existence of an additional neurodegenerative process. Fronto-subcortical networks appear to be involved in the disease progression at young adulthood in pediatric onset DM1 patients. The involvement of a multimodal integration network in DM1 is discussed.


Subject(s)
Executive Function/physiology , Magnetic Resonance Imaging , Myotonic Dystrophy/pathology , Neurodegenerative Diseases/pathology , Adult , Atrophy/pathology , Disease Progression , Female , Follow-Up Studies , Gray Matter/pathology , Humans , Magnetic Resonance Imaging/methods , Male , Middle Aged , Neuropsychological Tests , White Matter/pathology
8.
Genes (Basel) ; 11(5)2020 05 11.
Article in English | MEDLINE | ID: mdl-32403337

ABSTRACT

The term neuromuscular disorder (NMD) includes many genetic and acquired diseases and differential diagnosis can be challenging. Next-generation sequencing (NGS) is especially useful in this setting given the large number of possible candidate genes, the clinical, pathological, and genetic heterogeneity, the absence of an established genotype-phenotype correlation, and the exceptionally large size of some causative genes such as TTN, NEB and RYR1. We evaluated the diagnostic value of a custom targeted next-generation sequencing gene panel to study the mutational spectrum of a subset of NMD patients in Spain. In an NMD cohort of 207 patients with congenital myopathies, distal myopathies, congenital and adult-onset muscular dystrophies, and congenital myasthenic syndromes, we detected causative mutations in 102 patients (49.3%), involving 42 NMD-related genes. The most common causative genes, TTN and RYR1, accounted for almost 30% of cases. Thirty-two of the 207 patients (15.4%) carried variants of uncertain significance or had an unidentified second mutation to explain the genetic cause of the disease. In the remaining 73 patients (35.3%), no candidate variant was identified. In combination with patients' clinical and myopathological data, the custom gene panel designed in our lab proved to be a powerful tool to diagnose patients with myopathies, muscular dystrophies and congenital myasthenic syndromes. Targeted NGS approaches enable a rapid and cost-effective analysis of NMD- related genes, offering reliable results in a short time and relegating invasive techniques to a second tier.


Subject(s)
DNA Mutational Analysis/methods , High-Throughput Nucleotide Sequencing/methods , Mutation , Neuromuscular Diseases/genetics , Adolescent , Adult , Aged , Child , Child, Preschool , Female , Genetic Association Studies/methods , Humans , Infant , Infant, Newborn , Male , Middle Aged , Mitochondrial Diseases/diagnosis , Mitochondrial Diseases/epidemiology , Mitochondrial Diseases/genetics , Muscular Diseases/diagnosis , Muscular Diseases/epidemiology , Muscular Diseases/genetics , Neuromuscular Diseases/diagnosis , Neuromuscular Diseases/epidemiology , Spain/epidemiology , Young Adult
9.
Article in English | MEDLINE | ID: mdl-32106710

ABSTRACT

Objective: To perform a comprehensive lipid profiling to evaluate potential lipid metabolic differences between patients with amyotrophic lateral sclerosis (ALS) and controls, and to provide a more profound understanding of the metabolic abnormalities in ALS. Methods: Twenty patients with ALS and 20 healthy controls were enrolled in a cross-sectional study. Untargeted lipidomics profiling in fasting serum samples were performed by optimized UPLC-MS platforms for broad lipidome coverage. Datasets were analyzed by univariate and a variety of multivariate procedures. Results: We provide the most comprehensive blood lipid profiling of ALS to date, with a total of 416 lipids measured. Univariate analysis showed that 28 individual lipid features and two lipid classes, triacylglycerides and oxidized fatty acids (FAs), were altered in patients with ALS, although none of these changes remained significant after multiple comparison adjustment. Most of these changes remained constant after removing from the analysis individuals treated with lipid-lowering drugs. The non-supervised principal component analysis did not identify any lipid clustering of patients with ALS and controls. Despite this, we performed a variety of linear and non-linear supervised multivariate models to select the most reliable features that discriminate the lipid profile of patients with ALS from controls. These were the monounsaturated FAs C24:1n-9 and C14:1, the triglyceride TG(51:4) and the sphingomyelin SM(36:2). Conclusions: Peripheral alterations of lipid metabolism are poorly defined in ALS, triacylglycerides and certain types of FAs could contribute to the different lipid profile of patients with ALS. These findings should be validated in an independent cohort.


Subject(s)
Amyotrophic Lateral Sclerosis/blood , Amyotrophic Lateral Sclerosis/diagnosis , Lipidomics/methods , Tandem Mass Spectrometry/methods , Aged , Chromatography, High Pressure Liquid/methods , Cross-Sectional Studies , Female , Humans , Male , Middle Aged
11.
J Neuropsychol ; 14(1): 121-134, 2020 03.
Article in English | MEDLINE | ID: mdl-31407859

ABSTRACT

BACKGROUND: Myotonic dystrophy type 1 (DM1) is an inherited multi-systemic disease involving the central nervous system (CNS) and is consequently characterized by a range of cognitive impairments. However, whether this cognitive profile progresses over time is still a matter of debate. The aim of this study was to longitudinally assess a DM1 sample, in order to compare, for the first time, this progression with that of a control group. Clinical and socio-demographic predictive factors potentially implicated in this possible decline are analysed. METHOD: Seventy-five DM1 patients with childhood, juvenile, adult, and late-onset, and 54 control participants were re-assessed in an 11-year follow-up with a comprehensive neuropsychological battery. The analyses employed were mixed ANOVA for repeated measures to test intergroup comparisons over time and multiple linear regression for predictive variable analysis. RESULTS: Myotonic dystrophy type 1 patients significantly worsened in visuospatial/visuoconstructive abilities and visual memory compared with controls. Multiple linear regression revealed that progression of cognitive impairment measured by copy of the Rey-Osterrieth complex figure was predicted by muscular impairment, whilst on the block design test age predicted the change with a cut-off at 31 years of age. DISCUSSION: A domain-specific progressive cognitive decline was found in DM1, with visuospatial/visuoconstructive abilities showing the greatest vulnerability to the passage of time. In addition to important clinical implications, these results suggest the need for the scientific community to delve deeper into the potential mechanisms underlying early cognitive decline in this population.


Subject(s)
Cognitive Dysfunction/complications , Myotonic Dystrophy/psychology , Adolescent , Adult , Age Factors , Case-Control Studies , Disease Progression , Female , Follow-Up Studies , Humans , Longitudinal Studies , Male , Memory , Middle Aged , Multivariate Analysis , Neuropsychological Tests , Young Adult
12.
Ann Clin Transl Neurol ; 7(1): 105-111, 2020 01.
Article in English | MEDLINE | ID: mdl-31854126

ABSTRACT

OBJECTIVE: To identify causative mutations in a patient affected by ataxia and spastic paraplegia. METHODS: Whole-exome sequencing (WES) and whole-genome sequencing (WGS) were performed using patient's DNA sample. RT-PCR and cDNA Sanger sequencing were performed on RNA extracted from patient's fibroblasts, as well as western blot. RESULTS: A novel missense variant in SPG7 (c.2195T> C; p.Leu732Pro) was first found by whole-exome sequencing (WES), while the second, also unreported, deep intronic variant (c.286 + 853A>G) was identified by whole-genome sequencing (WGS). RT-PCR confirmed the in silico predictions showing that this variant activated a cryptic splice site, inducing the inclusion of a pseudoexon into the mRNA sequence, which encoded a premature stop codon. Western blot showed decreased SPG7 levels in patient's fibroblasts. INTERPRETATION: Identification of a deep intronic variant in SPG7, which could only have been detected by performing WGS, led to a diagnosis in this HSP patient. This case challenges the notion of an autosomal dominant inheritance for SPG7, and illustrates the importance of performing WGS subsequently or alternatively to WES to find additional mutations, especially in patients carrying one variant in a gene causing a predominantly autosomal recessive disease.


Subject(s)
ATPases Associated with Diverse Cellular Activities/genetics , Gait Ataxia/diagnosis , Introns/genetics , Metalloendopeptidases/genetics , Spastic Paraplegia, Hereditary/diagnosis , Gait Ataxia/genetics , Humans , Male , Middle Aged , Mutation, Missense , RNA Splicing , Spastic Paraplegia, Hereditary/genetics , Exome Sequencing , Whole Genome Sequencing
13.
Neuroimage Clin ; 24: 102078, 2019.
Article in English | MEDLINE | ID: mdl-31795042

ABSTRACT

BACKGROUND: Myotonic Dystrophy type 1 (DM1) is a slowly progressive myopathy characterized by varying multisystemic involvement. Several cerebral features such as brain atrophy, ventricular enlargement, and white matter lesions (WMLs) have frequently been described. The aim of this study is to investigate the structural organization of the brain that defines the disease through multimodal imaging analysis, and to analyze the relation between structural cerebral changes and DM1 clinical and neuropsychological profiles. METHOD: 31 DM1 patients and 57 healthy controls underwent an MRI scan protocol, including T1, T2 and DTI. Global gray matter (GM), global white matter (WM), and voxel-level Voxel Based Morphometry (VBM) and voxel-level microstructural WM abnormalities through Diffusion Tensor Imaging (DTI) were assessed through group comparisons and linear regression analysis with age, degree of muscular impairment (MIRS score), CTG expansion size and neuropsychological outcomes from a comprehensive assessment. RESULTS: Compared with healthy controls, DM1 patients showed a reduction in both global GM and WM volume; and further regional GM decrease in specific primary sensory, multi-sensory and association cortical regions. Fractional anisotropy (FA) was reduced in both total brain and regional analysis, being most marked in frontal, paralimbic, temporal cortex, and subcortical regions. Higher ratings on muscular impairment and longer CTG expansion sizes predicted a greater volume decrease in GM and lower FA values. Age predicted global GM reduction, specifically in parietal regions. At the cognitive level, the DM1 group showed significant negative correlations between IQ estimate, visuoconstructive and executive neuropsychological scores and both global and regional volume decrease, mainly distributed in the frontal, parietal and subcortical regions. CONCLUSIONS: In this study, we describe the structural brain signatures that delineate the involvement of the CNS in DM1. We show that specific sensory and multi-sensory - as well as frontal cortical areas - display potential vulnerability associated with the hypothesized neurodegenerative nature of DM1 brain abnormalities.


Subject(s)
Cognitive Dysfunction/diagnostic imaging , Gray Matter/diagnostic imaging , Myotonic Dystrophy/diagnostic imaging , White Matter/diagnostic imaging , Adolescent , Adult , Aged , Anisotropy , Atrophy , Case-Control Studies , Cognitive Dysfunction/psychology , Diffusion Tensor Imaging , Female , Gray Matter/pathology , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Myotonic Dystrophy/genetics , Myotonic Dystrophy/physiopathology , Myotonic Dystrophy/psychology , Myotonin-Protein Kinase/genetics , Trinucleotide Repeat Expansion , White Matter/pathology , Young Adult
15.
Proc Natl Acad Sci U S A ; 116(50): 25203-25213, 2019 12 10.
Article in English | MEDLINE | ID: mdl-31754023

ABSTRACT

Myotonic dystrophy type 1 (DM1) is a life-threatening and chronically debilitating neuromuscular disease caused by the expansion of a CTG trinucleotide repeat in the 3' UTR of the DMPK gene. The mutant RNA forms insoluble structures capable of sequestering RNA binding proteins of the Muscleblind-like (MBNL) family, which ultimately leads to phenotypes. In this work, we demonstrate that treatment with the antiautophagic drug chloroquine was sufficient to up-regulate MBNL1 and 2 proteins in Drosophila and mouse (HSALR) models and patient-derived myoblasts. Extra Muscleblind was functional at the molecular level and improved splicing events regulated by MBNLs in all disease models. In vivo, chloroquine restored locomotion, rescued average cross-sectional muscle area, and extended median survival in DM1 flies. In HSALR mice, the drug restored muscular strength and histopathology signs and reduced the grade of myotonia. Taken together, these results offer a means to replenish critically low MBNL levels in DM1.


Subject(s)
Chloroquine/administration & dosage , DNA-Binding Proteins/metabolism , Drosophila Proteins/metabolism , Myotonic Dystrophy/drug therapy , Myotonic Dystrophy/metabolism , Nuclear Proteins/metabolism , RNA-Binding Proteins/metabolism , Animals , Autophagy/drug effects , DNA-Binding Proteins/genetics , Disease Models, Animal , Drosophila , Drosophila Proteins/genetics , Female , Humans , Male , Mice , Muscles/drug effects , Muscles/metabolism , Myoblasts/drug effects , Myoblasts/metabolism , Myotonic Dystrophy/genetics , Myotonic Dystrophy/physiopathology , Nuclear Proteins/genetics , Phenotype , RNA Splicing/drug effects , RNA-Binding Proteins/genetics
16.
Mov Disord ; 34(10): 1547-1561, 2019 10.
Article in English | MEDLINE | ID: mdl-31433872

ABSTRACT

BACKGROUND: Pathogenic variants in the spastic paraplegia type 7 gene cause a complicated hereditary spastic paraplegia phenotype associated with classical features of mitochondrial diseases, including ataxia, progressive external ophthalmoplegia, and deletions of mitochondrial DNA. OBJECTIVES: To better characterize spastic paraplegia type 7 disease with a clinical, genetic, and functional analysis of a Spanish cohort of spastic paraplegia type 7 patients. METHODS: Genetic analysis was performed in patients suspecting hereditary spastic paraplegia and in 1 patient with parkinsonism and Pisa syndrome, through next-generation sequencing, whole-exome sequencing, targeted Sanger sequencing, and multiplex ligation-dependent probe analysis, and blood mitochondrial DNA levels determined by quantitative polymerase chain reaction. RESULTS: Thirty-five patients were found to carry homozygous or compound heterozygous pathogenic variants in the spastic paraplegia type 7 gene. Mean age at onset was 40 years (range, 12-63); 63% of spastic paraplegia type 7 patients were male, and three-quarters of all patients had at least one allele with the c.1529C>T (p.Ala510Val) mutation. Eighty percent of the cohort showed a complicated phenotype, combining ataxia and progressive external ophthalmoplegia (65% and 26%, respectively). Parkinsonism was observed in 21% of cases. Analysis of blood mitochondrial DNA indicated that both patients and carriers of spastic paraplegia type 7 pathogenic variants had markedly lower levels of mitochondrial DNA than control subjects (228 per haploid nuclear DNA vs. 176 vs. 573, respectively; P < 0.001). CONCLUSIONS: Parkinsonism is a frequent finding in spastic paraplegia type 7 patients. Spastic paraplegia type 7 pathogenic variants impair mitochondrial DNA homeostasis irrespective of the number of mutant alleles, type of variant, and patient or carrier status. Thus, spastic paraplegia type 7 supports mitochondrial DNA maintenance, and variants in the gene may cause parkinsonism owing to mitochondrial DNA abnormalities. Moreover, mitochondrial DNA blood analysis could be a useful biomarker to detect at risk families. © 2019 International Parkinson and Movement Disorder Society.


Subject(s)
DNA, Mitochondrial/genetics , Mitochondria/genetics , Mitochondrial Diseases/genetics , Paraplegia/genetics , Spastic Paraplegia, Hereditary/genetics , Adolescent , Adult , Child , Female , Humans , Male , Middle Aged , Mutation/genetics , Parkinsonian Disorders/genetics , Phenotype , Young Adult
17.
Brain ; 142(9): 2605-2616, 2019 09 01.
Article in English | MEDLINE | ID: mdl-31332438

ABSTRACT

Distal hereditary motor neuropathies are a rare subgroup of inherited peripheral neuropathies hallmarked by a length-dependent axonal degeneration of lower motor neurons without significant involvement of sensory neurons. We identified patients with heterozygous nonsense mutations in the αII-spectrin gene, SPTAN1, in three separate dominant hereditary motor neuropathy families via next-generation sequencing. Variable penetrance was noted for these mutations in two of three families, and phenotype severity differs greatly between patients. The mutant mRNA containing nonsense mutations is broken down by nonsense-mediated decay and leads to reduced protein levels in patient cells. Previously, dominant-negative αII-spectrin gene mutations were described as causal in a spectrum of epilepsy phenotypes.


Subject(s)
Carrier Proteins/genetics , Codon, Nonsense/genetics , Microfilament Proteins/genetics , Mutation/genetics , Peripheral Nervous System Diseases/diagnosis , Peripheral Nervous System Diseases/genetics , Adult , Aged , Aged, 80 and over , Child , Cohort Studies , Female , Humans , Male , Middle Aged , Pedigree , Young Adult
18.
Acta Neuropathol ; 138(2): 237-250, 2019 08.
Article in English | MEDLINE | ID: mdl-31131421

ABSTRACT

The genetic variant rs72824905-G (minor allele) in the PLCG2 gene was previously associated with a reduced Alzheimer's disease risk (AD). The role of PLCG2 in immune system signaling suggests it may also protect against other neurodegenerative diseases and possibly associates with longevity. We studied the effect of the rs72824905-G on seven neurodegenerative diseases and longevity, using 53,627 patients, 3,516 long-lived individuals and 149,290 study-matched controls. We replicated the association of rs72824905-G with reduced AD risk and we found an association with reduced risk of dementia with Lewy bodies (DLB) and frontotemporal dementia (FTD). We did not find evidence for an effect on Parkinson's disease (PD), amyotrophic lateral sclerosis (ALS) and multiple sclerosis (MS) risks, despite adequate sample sizes. Conversely, the rs72824905-G allele was associated with increased likelihood of longevity. By-proxy analyses in the UK Biobank supported the associations with both dementia and longevity. Concluding, rs72824905-G has a protective effect against multiple neurodegenerative diseases indicating shared aspects of disease etiology. Our findings merit studying the PLCγ2 pathway as drug-target.


Subject(s)
Dementia/genetics , Longevity/genetics , Mutation , Phospholipase C gamma/genetics , Alleles , Alzheimer Disease/genetics , Amyotrophic Lateral Sclerosis/genetics , Brain/immunology , Brain/metabolism , Brain/pathology , Frontotemporal Dementia/genetics , Genetic Predisposition to Disease , Genome-Wide Association Study , Humans , Lewy Body Disease/genetics , Microglia/metabolism , Multiple Sclerosis/genetics , Neuroimaging , Parkinson Disease/genetics , Risk
19.
Front Aging Neurosci ; 10: 380, 2018.
Article in English | MEDLINE | ID: mdl-30546303

ABSTRACT

Many factors may converge in healthy aging in the oldest old, but their association and predictive power on healthy or functionally impaired aging has yet to be demonstrated. By detecting healthy aging and in turn, poor aging, we could take action to prevent chronic diseases associated with age. We conducted a pilot study comparing results of a set of markers (peripheral blood mononuclear cell or PBMC telomere length, circulating Aß peptides, anti-Aß antibodies, and ApoE status) previously associated with poor aging or cognitive deterioration, and their combinations, in a cohort of "neurologically healthy" (both motor and cognitive) nonagenarians (n = 20) and functionally impaired, institutionalized nonagenarians (n = 38) recruited between 2014 and 2015. We recruited 58 nonagenarians (41 women, 70.7%; mean age: 92.37 years in the neurologically healthy group vs. 94.13 years in the functionally impaired group). Healthy nonagenarians had significantly higher mean PBMC telomere lengths (mean = 7, p = 0.001), this being inversely correlated with functional impairment, and lower circulating Aß40 (total in plasma fraction or TP and free in plasma fraction or FP), Aß42 (TP and FP) and Aß17 (FP) levels (FP40 131.35, p = 0.004; TP40 299.10, p = 0.007; FP42 6.29, p = 0.009; TP42 22.53, p = 0.019; FP17 1.32 p = 0.001; TP17 4.47, p = 0.3), after adjusting by age. Although healthy nonagenarians had higher anti-Aß40 antibody levels (net adsorbed signal or NAS ± SD: 0.211 ± 0.107), the number of participants that pass the threshold (NAS > 3) to be considered as positive did not show such a strong association. There was no association with ApoE status. Additionally, we propose a "Composite Neurologically Healthy Aging Score" combining TP40 and mean PBMC telomere length, the strongest correlation of measured biomarkers with neurologically healthy status in nonagenarians (AUC = 0.904).

20.
PLoS One ; 13(9): e0204227, 2018.
Article in English | MEDLINE | ID: mdl-30248121

ABSTRACT

AIMS: The cognitive profile of Myotonic Dystrophy type 1 (DM1) has been described in recent decades. Moreover, DM1 patients show lowered social engagement and difficulties in social-cognitive functions. The aim of the present study is to explore whether social cognition impairment is present in DM1 taking into account the overall cognitive condition. METHOD: 38 patients and a control group paired in age and gender participated in the study. All the participants had an IQ within the normal range. Subjects were administered an abbreviated neuropsychological battery which comprised a facial emotion recognition test (POFA) and Faux Pas Test, as well as a self-report questionnaire on cognitive and affective empathy (TECA). RESULTS: Statistically significant differences were found only for facial emotion recognition (U = 464.0, p = .006) with a moderate effect size (.31), with the controls obtaining a higher score than the patients. Analyzing each emotion separately, DM1 patients scored significantly lower than controls on the recognition of anger and disgust items. Emotion recognition did not correlate with genetic load, but did correlate negatively with age. No differences were found between patients and controls in any of the other variables related to Theory of Mind (ToM) and empathy. CONCLUSION: DM1 does not manifest specific impairments in ToM since difficulties in this area predominantly rely on the cognitive demand of the tasks employed. However, a more basic process such as emotion recognition appears as a core deficit. The role of this deficit as a marker of aging related decline is discussed.


Subject(s)
Cognition , Myotonic Dystrophy/psychology , Adult , Age Factors , Case-Control Studies , Emotions , Empathy , Facial Recognition , Female , Humans , Male , Middle Aged , Neuropsychological Tests , Self Report , Social Behavior
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