Identification and characterisation of novel genes in motor neuron disorders

Hereditary Motor Sensory Neuropathy (HMSN), also known as Charcot-Marie-Tooth disease (MIM118300), is an heterogeneous group of Mendelian diseases which affects the peripheral motor and sensory nervous system (PNS). With a prevalence of about 1/2500 individuals, it is considered the most common inherited neuromuscular disorder. The clinical hallmarks include slow and progressive muscular weakness of distal limbs, peroneal atrophy and bilateral pes cavus, however they are often associated with other signs such as spastic paraplegia, ataxia, mental retardation and incontinence. Distal HMN disorders are a subgroup of HMSN characterized by a predominant motor involvement and minor or no sensory loss. To date, more than 50 genes have been detected for HMSN and 17 genes for dHMN, but many disease-genes have to be identified yet. This study aims to identify and, whenever possible, functionally characterise novel genes causing different forms of peripheral neuropathy. In order to achieve this objective, four families affected by complex HMSN or distal HMN and showing no mutations in known disease-genes were examined. The identification of novel genes was performed by using a strategy which integrates the traditional positional cloning approach with the next-generation whole-exome sequencing. In all the four families candidate linkage regions were identified by genome-wide linkage analysis, specifically for the recessive forms they were identified also by homozygosity mapping and identity-by-descent analysis using high-density SNPs arrays and STR markers. In one family a candidate-genes screening by Sanger sequencing was preferred for the small size of the critical region. In the remaining three families the whole-exome sequencing (WES) approach was adopted in order to inspect all coding variants within the previously identified linkage regions. Considering the advantage of having variants within the whole exome, known disease-related genes were also analysed and less stringent genome wide searches were even conducted. Moreover, coverage analysis was performed and poorly-covered exons were sequenced. The best candidate variants were selected by filtering and prioritization analyses which allowed to evaluate the putative pathogenicity of variants. For the variants which represented potential mutations, further confirmations were obtained by in silico analyses, control population screening, unrelated patients characterization and functional studies. This work represents the first step to demonstrate the pathogenicity of a candidate variant and dissect the mechanisms underlying peripheral neuropathies

Avaliação do transtorno de estresse pós-traumático em sobreviventes de câncer infantil

Objetivo: avaliar sintomas de transtorno de estresse pós-traumático (TEPT) em sobreviventes de câncer infantil. Método: Participaram 65 sobreviventes que responderam a uma ficha de dados sociodemográficos e clínicos, Escala de Rastreio de Sintomas de Stress Pós-Traumático (SPTSS-17) e PTSD Checklist - Civilian Version (PCL-C). Resultados: A presença de sintomas de TEPT variou entre 9,2% e 18,5% nessa amostra. Com relação à sintomatologia, 41% apresentaram sintomas aumentados de revivência, 16,9% de evitação e 35,4% de excitabilidade aumentada. Não foram encontradas correlações significativas nos índices de TEPT e características sociodemográficas e clínicas da amostra. Conclusão: Os prejuízos dos sintomas de TEPT e a própria experiência traumática do câncer repercutem negativamente na vida do sobrevivente em longo prazo e podem não ser avaliados adequadamente pelos profissionais da saúde.Purpose: evaluate symptoms of post-traumatic stress disorder (PTSD) in childhood cancer survivors. Method: 65 survivors who answered to a clinical and sociodemographic questionnaire. PTSD symptoms screening scale (PTSDS-17) and PTSD checklist- Civilian version (PCL-C). Results: within the sample, PTSD symptoms presence varied between 9,2% and 18,5%. Referred to symptomatology, 41% showed symptoms of revival, 16,9% of avoidance and 35,4% of increased excitability. The PTSD, sociodemographic and clinical indexes of the sample showed no significant correlations. Conclusion: Cancer traumatic experience and PTSD symptoms harms will be of negative repercussion on survivors life in the long run and may not be adequately evaluated by health professionals

Posttraumatic Stress Disorder and Illness Perception in Young Survivors of Childhood Cancer

Objetivo: Este estudo teve como objetivo avaliar a presença de Transtorno de Estresse Pós-Traumático (TEPT) e a sua relação com a perceção da doença numa amostra de 65 jovens sobreviventes de cancro infantil, com uma média de idades de 19 anos (DP = 2,70) e que tinham terminado o tratamento, em média, há sete anos. Método: Foram aplicados instrumentos para obtenção de dados sociodemográficos e clínicos, de sintomas de TEPT – “Posttraumatic Stress Disorder Checklist – Civilian” (PCL-C) e de perceção da doença – “Revised Illness Perception Questionnaire for Healthy People” (IPQ-RH). Resultados: A presença de sintomas de TEPT variade 9,2% a 18,5% na amostra, e a perceção da doença esteve correlacionada com os sintomas deste transtorno. As subescalas Representação Emocional e Coerência da Doença (IPQ-RH), foram preditoras dos sintomas de Reexperiência (β = 0,0370; p < 0,01; β = 0,261; p < 0,05, respetivamente). A subescala Representação Emocional (IPQ-RH) também foi preditora de sintomas de Esquiva (β = 0,330; p < 0,001). Conclusão: Concluiu-se que a perceção da doença deve ser investigada para prevenir os sintomas de TEPT em sobreviventes de câncer infantil.Aim: This study assessed the presence of posttraumatic stress disorder (PTSD) symptoms and their relation to illness perception in a sample of 65 young survivors of childhood cancer, mean age of 19 years (SD = 2.70) and who had completed treatment, on average, seven years ago.  Method: The instruments used were: sociodemographic and clinical form, PTSD - Posttraumatic Stress Disorder Checklist – Civilian (PCL-C) and Illness Perception questionnaire - Revised Illness Perception Questionnaire for Healthy People (IPQ-RH). Results: The presence of PTSD symptoms ranged between 9.2% and 18.5% in this sample, and illness perception was correlated with the symptoms of this disorder. Emotional representations and Coherence (IPQ-RH) were predictive of Re-experience symptoms (ß = .0370, p < .01; ß = .261, p < .05, respectively). Emotional Representation subscale (IPQ-RH) was also predictive of Avoidance symptoms (ß = .330, p < .001). Conclusion: It was concluded that illness perception should be examined to prevent PTSD symptoms in childhood cancer survivors

Identification and characterisation of novel genes in motor neuron disorders

Hereditary Motor Sensory Neuropathy (HMSN), also known as Charcot-Marie-Tooth disease (MIM118300), is an heterogeneous group of Mendelian diseases which affects the peripheral motor and sensory nervous system (PNS). With a prevalence of about 1/2500 individuals, it is considered the most common inherited neuromuscular disorder. The clinical hallmarks include slow and progressive muscular weakness of distal limbs, peroneal atrophy and bilateral pes cavus, however they are often associated with other signs such as spastic paraplegia, ataxia, mental retardation and incontinence. Distal HMN disorders are a subgroup of HMSN characterized by a predominant motor involvement and minor or no sensory loss. To date, more than 50 genes have been detected for HMSN and 17 genes for dHMN, but many disease-genes have to be identified yet. This study aims to identify and, whenever possible, functionally characterise novel genes causing different forms of peripheral neuropathy. In order to achieve this objective, four families affected by complex HMSN or distal HMN and showing no mutations in known disease-genes were examined. The identification of novel genes was performed by using a strategy which integrates the traditional positional cloning approach with the next-generation whole-exome sequencing. In all the four families candidate linkage regions were identified by genome-wide linkage analysis, specifically for the recessive forms they were identified also by homozygosity mapping and identity-by-descent analysis using high-density SNPs arrays and STR markers. In one family a candidate-genes screening by Sanger sequencing was preferred for the small size of the critical region. In the remaining three families the whole-exome sequencing (WES) approach was adopted in order to inspect all coding variants within the previously identified linkage regions. Considering the advantage of having variants within the whole exome, known disease-related genes were also analysed and less stringent genome wide searches were even conducted. Moreover, coverage analysis was performed and poorly-covered exons were sequenced. The best candidate variants were selected by filtering and prioritization analyses which allowed to evaluate the putative pathogenicity of variants. For the variants which represented potential mutations, further confirmations were obtained by in silico analyses, control population screening, unrelated patients characterization and functional studies. This work represents the first step to demonstrate the pathogenicity of a candidate variant and dissect the mechanisms underlying peripheral neuropathies.La neuropatia ereditaria sensitivo-motoria (HMSN), anche denominata malattia di Charcot-Marie-Tooth (MIM118300), costituisce un gruppo eterogeneo di disordini mendeliani che colpiscono il sistema nervoso periferico motorio e sensitivo. Tale malattia è considerata il disordine neuromuscolare ereditario più comune, con una prevalenza stimata di 1 caso su 2500 nella popolazione. I segni clinici distintivi includono una progressiva ipostenia e ipotrofia dei muscoli distali degli arti, un’atrofia peroneale e piede cavo bilaterale. Questo fenotipo clinico è di frequente associato ad altri sintomi, quali la paraparesi spastica, il ritardo mentale, atassia e disturbi urinari. Le neuropatie ereditarie motorie distali (dHMN) costituiscono un sottogruppo delle neuropatie ereditarie sensitive-motorie, caratterizzato da un prevalente coinvolgimento motorio e un minore o assente interessamento sensitivo. Ad oggi, più di 50 geni sono stati associati alle neuropatie ereditarie sensitivo-motorie e 17 alle forme motorie distali, tuttavia molti geni rimangono ancora sconosciuti. Il presente studio si prefigge di identificare e possibilmente caratterizzare dal punto di vista funzionale, nuovi geni causativi di varianti ereditarie di neuropatia periferica. A tale scopo sono state studiate quattro famiglie in cui erano presenti soggetti affetti da HMSN complesse o dHMN e nelle quali erano state escluse le mutazioni nei geni malattia già noti. Al fine di identificare nuovi geni causativi, in questo lavoro è stata adottata una strategia che va ad integrare l’approccio tradizionale di clonaggio posizionale con il sequenziamento next-generation dell’esoma. Nelle quattro famiglie oggetto di studio, mediante SNPs ad alta densità e marcatori microsatelliti, è stata svolta una analisi di linkage genome-wide e si sono identificate regioni candidate; inoltre per le forme recessive si è proceduto con il mappaggio per omozigosità e l’analisi di identità per discendenza (IBD). In una di queste famiglie, data la ridotta estensione della regione candidata, lo screening mutazionale dei geni candidati è avvenuto per mezzo del sequenziamento diretto. Nelle rimanenti tre famiglie, invece, è stato adottato l’approccio di sequenziamento next-generation dell’esoma, al fine di analizzare tutte le varianti presenti negli esoni codificanti delle regioni in linkage. Il vantaggio di avere un’informazione estesa all’intero esoma ha permesso un’analisi genome-wide meno stringente e la ricerca delle varianti nei geni malattia già noti. L’analisi dell’efficienza di copertura delle regioni candidate ha permesso invece di sequenziare gli esoni poco coperti di queste regioni. Un’approfondita e dettagliata analisi di filtraggio e prioritizzazione ha reso possibile valutare la possibile patogenicità delle varianti e di identificare le migliori candidate. A partire da queste, ulteriori validazioni sono state poi ottenute mediante studi in silico, screening di popolazione di controllo, caratterizzazione di pazienti non imparentati e studi funzionali. Tale studio costituisce il primo step fondamentale per identificare nuovi geni causativi e studiare nel dettaglio i meccanismi alla base delle neuropatie distali. A tale scopo screening genetici su coorti di pazienti e studi funzionali potranno far luce sull’effettivo coinvolgimento di questi nuovi geni candidati nelle neuropatie periferiche

Transtorno de estresse pós-traumático e perceção da doença em jovens sobreviventes de cancro infantil

Objetivo: Este estudo teve como objetivo avaliar a presença de Transtorno de Estresse Pós-Traumático (TEPT) e a sua relação com a perceção da doença numa amostra de 65 jovens sobreviventes de cancro infantil, com uma média de idades de 19 anos (DP = 2,70) e que tinham terminado o tratamento, em média, há sete anos. Método: Foram aplicados instrumentos para obtenção de dados sociodemográficos e clínicos, de sintomas de TEPT – “Posttraumatic Stress Disorder Checklist – Civilian” (PCL-C) e de perceção da doença – “Revised Illness Perception Questionnaire for Healthy People” (IPQ-RH). Resultados: A presença de sintomas de TEPT variade 9,2% a 18,5% na amostra, e a perceção da doença esteve correlacionada com os sintomas deste transtorno. As subescalas Representação Emocional e Coerência da Doença (IPQ-RH), foram preditoras dos sintomas de Reexperiência (β = 0,0370; p < 0,01; β = 0,261; p < 0,05, respetivamente). A subescala Representação Emocional (IPQ-RH) também foi preditora de sintomas de Esquiva (β = 0,330; p < 0,001). Conclusão: Concluiu-se que a perceção da doença deve ser investigada para prevenir os sintomas de TEPT em sobreviventes de câncer infantil.Aim: This study assessed the presence of posttraumatic stress disorder (PTSD) symptoms and their relation to illness perception in a sample of 65 young survivors of childhood cancer, mean age of 19 years (SD = 2.70) and who had completed treatment, on average, seven years ago. Method: The instruments used were: sociodemographic and clinical form, PTSD - Posttraumatic Stress Disorder Checklist – Civilian (PCL-C) and Illness Perception questionnaire - Revised Illness Perception Questionnaire for Healthy People (IPQ-RH). Results: The presence of PTSD symptoms ranged between 9.2% and 18.5% in this sample, and illness perception was correlated with the symptoms of this disorder. Emotional representations and Coherence (IPQ-RH) were predictive of Re-experience symptoms (β = .0370, p < .01; β = .261, p < .05, respectively). Emotional Representation subscale (IPQ-RH) was also predictive of Avoidance symptoms (β = .330, p < .001). Conclusion: It was concluded that illness perception should be examined to prevent PTSD symptoms in childhood cancer survivors

Y-chromosome haplotypes and clan structure of the Sherpa of the Solukhumbu (Nepal): preliminary ethnogenetic considerations.

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Avaliação do transtorno de estresse pós-traumático em sobreviventes de câncer infantil

Objetivo: avaliar sintomas de transtorno de estresse pós-traumático (TEPT) em sobreviventes de câncer infantil. Método: Participaram 65 sobreviventes que responderam a uma ficha de dados sociodemográficos e clínicos, Escala de Rastreio de Sintomas de Stress Pós-Traumático (SPTSS-17) e PTSD Checklist - Civilian Version (PCL-C). Resultados: A presença de sintomas de TEPT variou entre 9,2% e 18,5% nessa amostra. Com relação à sintomatologia, 41% apresentaram sintomas aumentados de revivência, 16,9% de evitação e 35,4% de excitabilidade aumentada. Não foram encontradas correlações significativas nos índices de TEPT e características sociodemográficas e clínicas da amostra. Conclusão: Os prejuízos dos sintomas de TEPT e a própria experiência traumática do câncer repercutem negativamente na vida do sobrevivente em longo prazo e podem não ser avaliados adequadamente pelos profissionais da saúde.Purpose: evaluate symptoms of post-traumatic stress disorder (PTSD) in childhood cancer survivors. Method: 65 survivors who answered to a clinical and sociodemographic questionnaire. PTSD symptoms screening scale (PTSDS-17) and PTSD checklist- Civilian version (PCL-C). Results: within the sample, PTSD symptoms presence varied between 9,2% and 18,5%. Referred to symptomatology, 41% showed symptoms of revival, 16,9% of avoidance and 35,4% of increased excitability. The PTSD, sociodemographic and clinical indexes of the sample showed no significant correlations. Conclusion: Cancer traumatic experience and PTSD symptoms harms will be of negative repercussion on survivors life in the long run and may not be adequately evaluated by health professionals

A novel SACS mutation results in non-ataxic spastic paraplegia and peripheral neuropathy.

Background and purpose: Mutations in the SACS gene are commonly associated with autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS), a complex neurodegenerative disorder characterized by progressive degeneration of the cerebellum and spinal cord tracts. The aim of this study was to identify the genetic cause of the disease in an Italian family with spastic paraplegia and peripheral neuropathy. Methods: Affected subjects were subjected to a comprehensive neurological examination including electromyography and brain magnetic resonance imaging. Genetic studies included exclusion of known disease genes, genome-wide linkage analysis using high density single nucleotide polymorphism genotyping and candidate gene sequencing. Results: Molecular analyses revealed a novel missense mutation in the SACS gene (c.11,104A>G) occurring in a homozygous state in patients and absent in 700 Italian control chromosomes. The mutation led to the amino acid substitution p.Thr3702Ala in the sacsin protein, in a possible protein-protein interaction site of UBE3A binding domain. Conclusion: This study broadens the genetic spectrum of SACS mutations and expands the clinical ARSACS phenotype suggesting that the SACS gene can be considered in patients with non-canonical ARSACS clinical presentations

The pro-apoptotic BAX protein influences cell growth and differentiation from the nucleus in healthy interphasic cells

International audienceIt has become more and more evident that the BCL-2 family proteins mediate a wide range of non-apoptotic functions. The pro-apoptotic BAX protein has been reported in interphasic nuclei. Whether the nuclear form of BAX could be involved in non-apoptotic function is still unknown. Our study showed for the first time that BAX was associated with chromatin in vitro. Next, we used gain and loss of function approaches to decipher the potential role of nuclear BAX in non-apoptotic cells. In vitro, nuclear BAX promoted cell proliferation in lung epithelial cells and primary human lung fibroblasts by modulating CDKN1A expression. Interestingly, BAX occupancy of CDKN1A promoter was specifically enriched close to the transcription-starting site. Nuclear BAX also modulated the basal myofibroblastic differentiation and migration of primary human lung fibroblasts. Finally, BAX nuclear localization was associated in vivo with the remodelling of lung parenchyma during development, tumorigenesis as well as fibrosis compared to control adult human lungs. Hence, our study established for the first time, a strong link between the nuclear localization of the pro-apoptotic BAX protein and key basic cellular functions in the non-apoptotic setting