Applicazione del sequenziamento di nuova generazione nella caratterizzazione molecolare delle eredoatassie

La grande eterogenicità genica delle atassie ha reso fino ad oggi l’individuazione del gene causativo mediante sequenziamento tradizionale del DNA (metodo Sanger) una procedura lunga, parziale ed estremamente costosa. L’applicazione del sequenziamento massivo di nuova generazione, consentendo di analizzare una grande quantità di geni contemporaneamente, può facilitare l’individuazione di mutazioni patogenetiche, riducendo tempi di analisi e costi per campione. In questa tesi è stato messo a punto un pannello di sequenziamento massivo targettato a 82 geni, direttamente implicati o correlati con le eredoatassie cerebellari. Questo pannello è stato applicato allo studio molecolare di 30 pazienti affetti da eredoatassia, e non ancora diagnosticati dal punto di vista molecolare. In tutti i pazienti erano state già escluse le forme più frequenti di malattia. Lo sviluppo di una metodica di sequenziamento targettato di nuova generazione amplia la possibilità di comprendere le cause genetiche delle eredoatassie, di identificare nuove mutazioni, e permette di definire nuovi fenotipi clinici offrendo una più completa correlazione genotipo-fenotipo

Integrative Organelle-Based Functional Proteomics: In Silico Prediction of Impaired Functional Annotations in SACS KO Cell Model

Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) is an inherited neurodegenerative disease characterized by early-onset spasticity in the lower limbs, axonal-demyelinating sensorimotor peripheral neuropathy, and cerebellar ataxia. Our understanding of ARSACS (genetic basis, protein function, and disease mechanisms) remains partial. The integrative use of organelle-based quantitative proteomics and whole-genome analysis proposed in the present study allowed identifying the affected disease-specific pathways, upstream regulators, and biological functions related to ARSACS, which exemplify a rationale for the development of improved early diagnostic strategies and alternative treatment options in this rare condition that currently lacks a cure. Our integrated results strengthen the evidence for disease-specific defects related to bioenergetics and protein quality control systems and reinforce the role of dysregulated cytoskeletal organization in the pathogenesis of ARSACS.Peer reviewe

Integrative Organelle-Based Functional Proteomics: In Silico Prediction of Impaired Functional Annotations in SACS KO Cell Model

Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) is an inherited neurodegenerative disease characterized by early-onset spasticity in the lower limbs, axonal-demyelinating sensorimotor peripheral neuropathy, and cerebellar ataxia. Our understanding of ARSACS (genetic basis, protein function, and disease mechanisms) remains partial. The integrative use of organelle-based quantitative proteomics and whole-genome analysis proposed in the present study allowed identifying the affected disease-specific pathways, upstream regulators, and biological functions related to ARSACS, which exemplify a rationale for the development of improved early diagnostic strategies and alternative treatment options in this rare condition that currently lacks a cure. Our integrated results strengthen the evidence for disease-specific defects related to bioenergetics and protein quality control systems and reinforce the role of dysregulated cytoskeletal organization in the pathogenesis of ARSACS

Integrative Organelle-Based Functional Proteomics: In Silico Prediction of Impaired Functional Annotations in SACS KO Cell Model

Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) is an inherited neurodegenerative disease characterized by early-onset spasticity in the lower limbs, axonal-demyelinating sensorimotor peripheral neuropathy, and cerebellar ataxia. Our understanding of ARSACS (genetic basis, protein function, and disease mechanisms) remains partial. The integrative use of organelle-based quantitative proteomics and whole-genome analysis proposed in the present study allowed identifying the affected disease-specific pathways, upstream regulators, and biological functions related to ARSACS, which exemplify a rationale for the development of improved early diagnostic strategies and alternative treatment options in this rare condition that currently lacks a cure. Our integrated results strengthen the evidence for disease-specific defects related to bioenergetics and protein quality control systems and reinforce the role of dysregulated cytoskeletal organization in the pathogenesis of ARSACS

Expanding the clinical and genetic heterogeneity of SPAX5

Mutations in the ATPase family 3-like gene (AFG3L2) have been linked to autosomal-dominant spinocerebellar ataxia type 28 and autosomal recessive spastic ataxia-neuropathy syndrome. Here, we describe the case of a child carrying bi-allelic mutations in AFG3L2 and presenting with ictal paroxysmal episodes associated with neuroimaging suggestive of basal ganglia involvement. Studies in skin fibroblasts showed a significant reduction of AFG3L2 expression. The relatively mild clinical presentation and the benign course, in spite of severe neuroimaging features, distinguish this case from data reported in the literature, and therefore expand the spectrum of neurological and neuroradiological features associated with AFG3L2 mutations

Loss of ap4s1 in zebrafish leads to neurodevelopmental defects resembling spastic paraplegia 52.

Autosomal recessive spastic paraplegia 52 is caused by biallelic mutations in AP4S1 which encodes a subunit of the adaptor protein complex 4 (AP-4). Using next-generation sequencing, we identified three novel unrelated SPG52 patients from a cohort of patients with cerebral palsy. The discovered variants in AP4S1 lead to reduced AP-4 complex formation in patient-derived fibroblasts. To further understand the role of AP4S1 in neuronal development and homeostasis, we engineered the first zebrafish model of AP-4 deficiency using morpholino-mediated knockdown of ap4s1. In this model, we discovered several phenotypes mimicking SPG52, including altered CNS development, locomotor deficits, and abnormal neuronal excitability

The association between reasons for first using cannabis, later pattern of use, and risk of first-episode psychosis: the EU-GEI case-control study

BACKGROUND: While cannabis use is a well-established risk factor for psychosis, little is known about any association between reasons for first using cannabis (RFUC) and later patterns of use and risk of psychosis. METHODS: We used data from 11 sites of the multicentre European Gene-Environment Interaction (EU-GEI) case-control study. 558 first-episode psychosis patients (FEPp) and 567 population controls who had used cannabis and reported their RFUC.We ran logistic regressions to examine whether RFUC were associated with first-episode psychosis (FEP) case-control status. Path analysis then examined the relationship between RFUC, subsequent patterns of cannabis use, and case-control status. RESULTS: Controls (86.1%) and FEPp (75.63%) were most likely to report 'because of friends' as their most common RFUC. However, 20.1% of FEPp compared to 5.8% of controls reported: 'to feel better' as their RFUC (χ2 = 50.97; p < 0.001). RFUC 'to feel better' was associated with being a FEPp (OR 1.74; 95% CI 1.03-2.95) while RFUC 'with friends' was associated with being a control (OR 0.56; 95% CI 0.37-0.83). The path model indicated an association between RFUC 'to feel better' with heavy cannabis use and with FEPp-control status. CONCLUSIONS: Both FEPp and controls usually started using cannabis with their friends, but more patients than controls had begun to use 'to feel better'. People who reported their reason for first using cannabis to 'feel better' were more likely to progress to heavy use and develop a psychotic disorder than those reporting 'because of friends'

The association between reasons for first using cannabis, later pattern of use, and risk of first-episode psychosis: the EU-GEI case-control study

Background While cannabis use is a well-established risk factor for psychosis, little is known about any association between reasons for first using cannabis (RFUC) and later patterns of use and risk of psychosis. Methods We used data from 11 sites of the multicentre European Gene-Environment Interaction (EU-GEI) case–control study. 558 first-episode psychosis patients (FEPp) and 567 population controls who had used cannabis and reported their RFUC. We ran logistic regressions to examine whether RFUC were associated with first-episode psychosis (FEP) case–control status. Path analysis then examined the relationship between RFUC, subsequent patterns of cannabis use, and case–control status. Results Controls (86.1%) and FEPp (75.63%) were most likely to report ‘because of friends’ as their most common RFUC. However, 20.1% of FEPp compared to 5.8% of controls reported: ‘to feel better’ as their RFUC (χ2 = 50.97; p < 0.001). RFUC ‘to feel better’ was associated with being a FEPp (OR 1.74; 95% CI 1.03–2.95) while RFUC ‘with friends’ was associated with being a control (OR 0.56; 95% CI 0.37–0.83). The path model indicated an association between RFUC ‘to feel better’ with heavy cannabis use and with FEPp-control status. Conclusions Both FEPp and controls usually started using cannabis with their friends, but more patients than controls had begun to use ‘to feel better’. People who reported their reason for first using cannabis to ‘feel better’ were more likely to progress to heavy use and develop a psychotic disorder than those reporting ‘because of friends’