Therapeutic tools for familial ALS

Familial ALS (FALS) accounts for 10 to 15% of ALS cases. In more than 70% of FALS patients, a causal gene is identified and animal models have been developed for a subset of them, mainly for the most frequently mutated genes. Therapeutic tools to treat those patients are dominated by gene-specific therapy and the most advanced approaches target the SOD1 gene mutations. Either by direct delivery of antisense oligonucleotides (ASO) or using viral vectors such as adenoviruses (AAV) to deliver ASOs, gene specific therapies have shown promising results in animal models. The recent use of subpial injections of AAV9+anti SOD1 ASO now shows that the disease is completely prevented or stopped in the animal, depending on the moment of injection, e.g., before or after disease onset. However, the use of viral vectors in humans seems to be limited at least by their immunogenicity. Antibody-based therapies are also efficient to treat animal models, but to a lesser extent. Most of the experiments targeted the SOD1 protein in its misfolded conformation. This approach seems better tolerated than the AAV one, an important limit being the choice of the epitope. Unexpectedly, some advances in treating the C9ORF72 animal model have been obtained using a modulation of microbiota, and this strategy has the great advantage to have an easy route of administration and a good safety profile. The landscape of experimental FALS treatment is rapidly evolving and results are promising. This is an important unmet need for ALS patients and several human phase I, II and III trials are ongoing.

An amyotrophic lateral sclerosis hot spot in the French Alps associated with genotoxic fungi

Between 1990 and 2018, 14 cases of amyotrophic lateral sclerosis (ALS) were diagnosed in residents of, and in visitors with second homes to, a mountainous hamlet in the French Alps. Systematic investigation revealed a socio-professional network that connected ALS cases. Genetic risk factors for ALS were excluded. Several known environmental factors were scrutinized and eliminated, notably lead and other chemical contaminants in soil, water or home-grown vegetation used for food, radon and electromagnetic fields. Some lifestyle-related behavioral risk factors were identified: Prior to clinical onset of motor neuron disease, some patients had a high degree of athleticism and smoked tobacco. Recent investigations on site, based on a new hypothesis, showed that all patients had ingested wild mushrooms, notably poisonous False Morels. Half of the ALS cohort reported acute illness following Gyromitra gigas mushroom consumption. This finding supports the hypothesis that genotoxins of fungal origin may induce motor neuron degeneration.

Autosomal dominant SPG9: intrafamilial variability and onset during pregnancy

INTRODUCTION

The ALDH18A1 gene, encoding delta-1-pyrroline-5-carboxylate synthase (P5CS), is responsible for an autosomal recessive disease with severe developmental delay; more recently, ALDH18A1 was found to be responsible for SPG9, an autosomal dominant (AD) spastic paraplegia.

CASE REPORT

We report a three-generation family with AD SPG9, initially suspected because of low citrulline on fasting plasma amino acid chromatography (AAC). Interestingly, in two patients, the spastic paraplegia appeared during pregnancy. One subject presented a severe childhood-onset form while another subject had a mild late-onset disease.

CONCLUSION

The description of this family is of particular interest: it highlights the possibility of transient or permanent aggravation of spastic paraplegia due to SPG9 during pregnancy, suggesting a direct link between neurological symptoms and amino acid defect in a period of higher requirements and the potential benefit of amino acid supplementation; it underscores the value of plasma citrulline on fasting plasma AAC as a biomarker for this disease; it shows the variable expression of the disease.

Pre-symptomatic diagnosis in ALS

Pathophysiology of amyotrophic lateral sclerosis (ALS) remains partially understood even though it is accepted worldwide that motor neuron death results from a pluri-factorial process with a variable role of genetic factors. Although not distinguishable from a clinical point of view, familial forms of ALS (fALS, 10% of cases) and sporadic forms (sALS, 90% of cases) can be described. Since the identification of superoxide dismutase 1 gene (SOD1) mutations, more than 30 genes have been linked to fALS. Among these genes, five (C9ORF72, SOD1, TARDBP, FUS, TBK1) seem predominant with mutation frequencies of 40%, 20%, 5%, <5%, <5% in fALS and 6%, 3%, and <1% for the last three in sALS, respectively. The situation that classically leads to request genetic screening is the presence of a familial history of motor neuron disorders (MND) or fronto-temporal lobar dementia (FTLD). However, this dichotomy between fALS and sALS based on familial history can lead to mistakes since illegitimacy, ignorance of MND, FTD or psychiatric disorders within the family due to a familial censorship or lack of familial relationship, or a recessive autosomal inheritance could wrongly lead to failing to recognize a familial form. The significant development of genetic research and easier access to genetic tests in fALS increase the number of situations for which gene mutations are identified. The consequence is an increase in genetic requests from relatives of ALS patients who are eager to know their own genetic status and their own individual risk to develop ALS. Pre-symptomatic testing is thus becoming a daily issue in ALS Centers. This led us to propose a framework for such pre-symptomatic genetic testing for people at risk for developing ALS.

MACVIA-LR (Fighting Chronic Diseases for Active and Healthy Ageing in Languedoc-Roussillon): A Success Story of the European Innovation Partnership on Active and Healthy Ageing

The Région Languedoc Roussillon is the umbrella organisation for an interconnected and integrated project on active and healthy ageing (AHA). It covers the 3 pillars of the European Innovation Partnership on Active and Healthy Ageing (EIP on AHA): (A) Prevention and health promotion, (B) Care and cure, (C) and (D) Active and independent living of elderly people. All sub-activities (poly-pharmacy, falls prevention initiative, prevention of frailty, chronic respiratory diseases, chronic diseases with multimorbidities, chronic infectious diseases, active and independent living and disability) have been included in MACVIA-LR which has a strong political commitment and involves all stakeholders (public, private, patients, policy makers) including CARSAT-LR and the Eurobiomed cluster. It is a Reference Site of the EIP on AHA. The framework of MACVIA-LR has the vision that the prevention and management of chronic diseases is essential for the promotion of AHA and for the reduction of handicap. The main objectives of MACVIA-LR are: (i) to develop innovative solutions for a network of Living labs in order to reduce avoidable hospitalisations and loss of autonomy while improving quality of life, (ii) to disseminate the innovation. The three years of MACVIA-LR activities are reported in this paper.

Chitinase 3-like proteins as diagnostic and prognostic biomarkers of multiple sclerosis

Background:

Despite sensitivity of MRI to diagnose multiple sclerosis (MS), prognostic biomarkers are still needed for optimized treatment.

Objective:

The objective of this paper is to identify cerebrospinal fluid (CSF) diagnostic biomarkers of MS using quantitative proteomics and to analyze their expression at different disease stages.

Methods:

We conducted differential analysis of the CSF proteome from control and relapsing–remitting MS (RRMS) patients followed by verification by ELISA of candidate biomarkers in CSF and serum in control, clinically isolated syndrome (CIS), RRMS and progressive MS (PMS) patients.

Results:

Twenty-two of the 527 quantified proteins exhibited different abundances in control and RRMS CSF. These include chitinase 3-like protein 1 (CHI3L1) and 2 (CHI3L2), which showed a strong expression in brain of MS patients, especially in astrocytes and microglial cells from white matter plaques. CSF and serum CHI3L1 levels increased with the disease stage and CIS patients with high CSF (>189 ng/ml) and serum (>33 ng/ml) CHI3L1 converted more rapidly to RRMS (log rank test, p < 0.05 and p < 0.001, respectively). In contrast, CSF CHI3L2 levels were lower in PMS than in RRMS patients. Accordingly, CSF CHI3L1/CHI3L2 ratio accurately discriminated PMS from RRMS.

Conclusions:

CSF CHI3L1 and CHI3L2 and serum CHI3L1 might help to define MS disease stage and have a prognostic value in CIS.

Neurotrophic factors in development and plasticity of spinal neurons

Factors affecting neuronal growth may be considered to fall into two major categories: those required for neuronal survival during development or following a lesion, and those which enhance growth or regeneration of axonal or dendritic processes. We briefly review here some recent studies on the former in spinal cord development and plasticity as an introduction to other papers in the session on Factors controlling Neural Growth, and then present in more detail work on factors affecting motoneuron development in vitro. The neurotrophins are a closely-related family of basic neurotrophic factors including nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) and neurotrophins -3, -4 and -5 that enhance neuronal survival by binding to surface receptors whose major components are the trk tyrosine kinases and p75NGF-R. Only the latter has been studied in the context of spinal cord neuroplasticity: its levels on motoneurons are up-regulated following central or peripheral trauma, although its function there remains unknown. Much evidence exists for the existence of 'motoneuron growth factors' involved in regulation of survival and development of spinal motoneurons. Following a critical comparison of techniques for their purification, we review results obtained in vitro and in vivo using known growth factors such as ciliary neurotrophic factor (CNTF), basic fibroblast growth factor (bFGF) and transforming growth factor (TGF/β1). Although none of them satisfies all the criteria for the embryonic 'motoneuron growth factor', CNTF is of potential interest for reducing motoneuron loss in pathological situations.

Respiratory onset in an ALS family with L144F SOD1 mutation

Familial amyotrophic lateral sclerosis (FALS) cases linked to SOD1 mutations may sometimes present with unusual clinical features such as pure lower motor neuron involvement or sensory signs. The authors describe a FALS pedigree with the L144F SOD1 mutation in which all cases had respiratory involvement as a first symptom. Although atypical clinical features are not rare in ALS families, this is the first pedigree with respiratory-onset in three affected members. This unusual presentation led to delayed diagnosis in the proband and highlights the fact that respiratory-onset can occur in familial ALS cases carrying SOD1 mutation.

[Demyelinating disease affecting both central and peripheral nervous system]

INTRODUCTION

Demyelinating disease affecting both the central and the peripheral nervous systems has rarely been reported.

CASE REPORT

A 30-year-old man, presented with ataxia and diffuse areflexia due to polyneuropathy fullfilling demyelination criteria. His medical history was notable for central nervous system demyelination compatible with multiple sclerosis. He improved transiently with intravenous immunoglobulin and then stabilized with methotrexate.

CONCLUSION

This case report distinguishes a new kind of inflammatory disease affecting both central and peripheral nervous system. It seems to be different from multiple sclerosis and chronic immune demyelinating polyneuropathy, because of high hyperproteinorachia and absence of oligoclonal bands in the cerebrospinal fluid.

APOE ε4 allele is associated with an increased risk of bulbar-onset amyotrophic lateral sclerosis in men

OBJECTIVE

  Several association studies have identified possible susceptibility factors for sporadic amyotrophic lateral sclerosis (SALS). Studies on the APOE gene provided conflicting results, especially about the effect on bulbar onset. We assessed the possible role of APOE gene in a large cohort of patients with ALS and matched controls.

METHODS

  The APOE alleles were determined in 1482 patients with SALS and 955 controls and analysed by univariate and multivariate statistics, taking into account gender, site-of-onset and age-at-onset.

RESULTS

  Patients with bulbar onset were more likely to be women [odds ratio (OR)=2.17; 95% CI: 1.74-2.72] and to be older (OR=3.47; 95% CI: 2.58-4.67). The ε4-carriers were more frequent in the bulbar-onset group than in the limb-onset group (OR=1.39 bulbar onset versus limb onset; 95% CI: 1.08-1.80) but this association was observed amongst men (OR=1.78; 95% CI: 1.25-2.53) and not women (OR=1.09; 95% CI: 0.75-1.59).

CONCLUSION

  Our study provides evidence for a contribution of the ε4 allele in the occurrence of bulbar-onset ALS amongst men. We propose that men are normally protected by androgens against bulbar onset and that the ε4 allele inhibits this protection, perhaps by interfering with the androgen pathway.

High-risk syndrome for neuromyelitis optica: a descriptive and comparative study

Background: Neuromyelitis optica (NMO) frequently begins with a monofocal episode of optic neuritis or myelitis. A concept named high-risk syndrome (HRS) for NMO has been proposed for patients with monofocal episodes and NMO-IgG antibodies.

Objective: To describe HRS patients and compare them with NMO patients.

Methods: We identified 30 patients with HRS: 18 with extensive myelitis (HRM) and 12 with optic neuritis (HRON), in a database pooling patients from 25 centres in France. Clinical, laboratory/magnetic resonance imaging (MRI) data and outcome were analysed and compared with a national cohort of 125 NMO patients extracted from the same database.

Results: Mean follow-up was 4.8 years. Mean age at onset was 42.8 years (range: 12.4–70) with a female:male ratio of 0.9. Asymptomatic lesions were report on visual evoked potentials in 4/8 tested HRM patients and on spinal cord MRI in 2/7 HRON patients. Three patients died, two owing to a cervical lesion. HRS and NMO patients had similar clinical/paraclinical data, except for a predominance of men in the HRS group and a later mean age at onset in the HRM subgroup.

Conclusion: The description of HRS patients is compatible with a monofocal form of NMO. Asymptomatic lesions could be included in a new set of NMO diagnostic criteria.

Long-term follow-up of neuromyelitis optica with a pediatric onset

BACKGROUND

Neuromyelitis optica (NMO) is a rare inflammatory disease. Average age at onset is 35 years. Few data exist on patients with pediatric-onset NMO (p-NMO), with disease onset before age 18 years. We report the clinical and paraclinical features and long-term outcome of patients with p-NMO and compare them with a large adult-onset NMO (a-NMO) cohort.

METHODS

We performed a retrospective, multicenter study of patients with p-NMO in pediatric and adult medical centers. We identified 125 patients with NMO (12 p-NMO; 113 a-NMO) fulfilling the 2006 criteria. Data were collected using hospital files and standardized assessment forms for NMO.

RESULTS

Patients with p-NMO were followed up during a mean 19.3 years. Median age at onset was 14.5 years (4.1-17.9) with a female:male ratio of 3:1. Three patients (25%) fulfilled Paty criteria for multiple sclerosis on first brain MRI, including one patient with acute disseminated encephalomyelitis. Median interval between onset and residual Expanded Disability Status Scale (EDSS) score 4 was 20.7 years, score 6 was 26 years, and score 7 was 28.7 years. Median interval between onset and residual visual loss ≤1/10 was 1.3 years. Compared with a-NMO, p-NMO showed a longer time to EDSS scores 4 and 6, largely explained by the severity of the first myelitis in the a-NMO group. Time to first treatment was longer in the p-NMO group (13.1 vs 3.4 years).

CONCLUSION

Patients with p-NMO can present a diffuse inflammatory process on first brain MRI and have a longer time to disability than patients with a-NMO.

[Longitudinal study of health related quality of life in multiple sclerosis: correlation with MRI parameters]

INTRODUCTION

Health related quality of life (HRQOL) is often affected in multiple sclerosis (MS). Nevertheless, to our knowledge, there is no longitudinal study in the literature about the correlation between MRI parameters and HRQOL in MS patients.

METHODS

We included 28 patients with clinically definite relapsing remitting MS. All patients initiated subcutaneous interferon beta-1a therapy. To assess HRQOL, we used the SEP-59 scale, the French validated translation of MSQOL-54, and the MusiQoL scale. Conventional MRI was performed every year. Lesion load (LL) and brain atrophy were automatically measured using SepINRIA, a free software developed by INRIA in Sophia Antipolis.

RESULTS

The mean EDSS score was 1.7 and disease duration was 2.5 years. Our results revealed that HRQOL was significantly correlated to T1 and T2-LL with both SEP-59 and MusiQoL scales. T1-LL was better correlated with physical dimensions and T2-LL was better correlated with mental components. At 1-year follow-up, patients whose MRI showed either an increase of T1 LL or at least one gadolinium enhancing lesion had a worse HRQOL at the end of the study. Initial brain parenchymal fraction (BPF) measure was also correlated with the long-term follow-up HRQOL. EDSS scored at the end of the study had not significantly changed (1.3; P>0.05).

CONCLUSION

Our study revealed pertinent clinicoradiological correlations between HRQOL and MRI parameters in our cohort.

Neuromyelitis optica in France: a multicenter study of 125 patients

BACKGROUND

There have been few epidemiologic studies on neuromyelitis optica (NMO) and none used the recent 2006 diagnostic criteria. Here we describe the clinical, laboratory, MRI, and disability course of NMO in a French cohort of 125 patients.

METHODS

We performed an observational, retrospective, multicenter study. Data were collected from September 2007 through August 2008, corresponding to the endpoint of the study. We identified 125 patients fulfilling the 2006 NMO criteria. Selection was made using hospital files and a specific clinical questionnaire for NMO.

RESULTS

Mean age at onset was 34.5 years (range 4-66) with a mean disease duration of 10 +/- 7.8 years at the endpoint. The patients were mainly (87%) Caucasian, with a female:male ratio of 3:1. In 90% of cases, the association of optic neuritis, longitudinal extensive myelitis, and a Paty-negative initial brain MRI was sufficient to fulfill the supportive criteria. Eighty-eight percent of patients were treated with immunosuppressive therapies. Median delay from onset to Expanded Disability Status Scale (EDSS) score 4 was 7 years; score 6, 10 years; and score 7, 21 years. The first episode of myelitis was immediately followed by an EDSS score > or = 4 in 37.3% of cases, and a severe residual visual loss was observed in 22% of patients after the first episode of optic neuritis. Multivariate analysis did not reveal any predictors of a poor evolution other than a high number of MRI brain lesions at diagnosis, which were predictive of a residual visual acuity < or = 1/10.

CONCLUSIONS

Our demographic data provide new data on disability in patients with neuromyelitis optica, most of whom were receiving treatment.

Mutations in FUS cause FALS and SALS in French and French Canadian populations

BACKGROUND

The identification of mutations in the TARDBP and more recently the identification of mutations in the FUS gene as the cause of amyotrophic lateral sclerosis (ALS) is providing the field with new insight about the mechanisms involved in this severe neurodegenerative disease.

METHODS

To extend these recent genetic reports, we screened the entire gene in a cohort of 200 patients with ALS. An additional 285 patients with sporadic ALS were screened for variants in exon 15 for which mutations were previously reported.

RESULTS

In total, 3 different mutations were identified in 4 different patients, including 1 3-bp deletion in exon 3 of a patient with sporadic ALS and 2 missense mutations in exon 15 of 1 patient with familial ALS and 2 patients with sporadic ALS.

CONCLUSIONS

Our study identified sporadic patients with mutations in the FUS gene. The accumulation and description of different genes and mutations helps to develop a more comprehensive picture of the genetic events underlying amyotrophic lateral sclerosis.

Hypocretinergic dysfunction in neuromyelitis optica with coma-like episodes

Devic's neuromyelitis optica (NMO) is a severe demyelinating disease of the central nervous system, often misdiagnosed as multiple sclerosis, and involving mainly optic nerves and the spinal cord. We report on a peculiar case of relapsing NMO with severe recurrent dysautonomia and hypersomnia, in which we had the opportunity to observe a dramatic decrease in hypocretin/orexin cerebrospinal fluid level.

Causes of death amongst French patients with amyotrophic lateral sclerosis: a prospective study

BACKGROUND AND PURPOSE

To prospectively investigate causes of death and the circumstances surrounding death in 302 patients with amyotrophic lateral sclerosis (ALS). The functional status of patients immediately before death was also determined.

METHODS

Information was obtained from neurologists at ALS centres, patients' files, and, when deaths occurred outside a medical facility, attending physicians.

RESULTS

Most patients (63%) died in a medical facility. The most frequently reported cause of death was respiratory failure (77%), including terminal respiratory insufficiency (58%), pneumonia (14%), asphyxia due to a foreign body (3%) and pulmonary embolism (2%). Ten per cent of patients died from other causes: post-surgical or traumatic conditions (5%), cardiac causes (3.4%), suicide (1.3%) and sudden death of unknown origin (0.7%). The cause of death could not be determined in 13% of cases (6% inside a medical facility and 25% outside). At the time of death, only 55% of patients were receiving riluzole, 33% were undergoing non-invasive ventilation, 3% had a tracheotomy and 37% a gastrostomy.

CONCLUSION

The information provided by this study helps to improve our understanding of the natural history of the disease and may help optimize the quality of care we can offer patients at the end of life.

Contribution of TARDBP mutations to sporadic amyotrophic lateral sclerosis

AIMS AND BACKGROUND

Mutations in the TARDBP gene, which encodes the TAR DNA binding protein (TDP-43), have been described in individuals with familial and sporadic amyotrophic lateral sclerosis (ALS). We screened the TARDBP gene in 285 French sporadic ALS patients to assess the frequency of TARDBP mutations in ALS.

RESULTS

Six individuals had potentially deleterious mutations of which three were novel including a Y374X truncating mutation and P363A and A382P missense mutations. This suggests that TARDBP mutations may predispose to ALS in approximately 2% of the individuals followed in this study.

CONCLUSION

Our findings, combined with those from other collections, brings the total number of mutations in unrelated ALS patients to 17, further suggesting that mutations in the TARDBP gene have an important role in the pathogenesis of ALS.

[Sensory-motor neuropathy: a slow and misleading case of leprosy]

The diagnostic process of sensory-motor neuropathies is difficult. Atypical variants and rare etiologies also contribute to delay the diagnosis. We report the case of a 70-year-old woman with slowly progressive asymmetric axonal sensory-motor neuropathy. Leprosy was identified after an eight-year delay. Nerve biopsy was required to establish the diagnosis: electron microscopy revealed debris of Hansen's bacillus in the nerve. Treatment was fully curative after several months. Leprosy is a rare cause of neuropathy in Europeans. Systematic inquiry about travel to endemic areas would be helpful in establishing the diagnosis. In such cases, nerve biopsy is crucial.

Erythema nodosum and glatiramer acetate treatment in relapsing-remitting multiple sclerosis

Glatiramer acetate (GA), a well tolerated immunomodulatory treatment for relapsing—remitting multiple sclerosis (RR-MS), consists of a 4-amino acid polymer that mimics the myelin basic protein (MBP). We report the first case of biopsy-proven erythema nodosum (EN) in a patient presenting RR-MS under GA treatment. Comprehensive exams were negative in the search of the etiology of EN, which spontaneously resolved despite treatment continuation. GA treatment is known to generate reactive polyclonal antibodies that can cross-react with myelin epitopes, like MBP. These antibodies may also be implicated in allergenic reactions and auto-immune adverse events, such as anaphylactic shock, lymphadenopathy, livedo-like dermatitis, or lymphocytic infiltration. EN is an unspecific skin reaction occurring in several disorders and induced by many treatments. As EN can result from a polyclonal antibody response or type I hypersensitivity mechanisms, we hypothesize that GA treatment could be responsible for the occurrence of EN. Multiple Sclerosis 2007; 13: 941—944. http://msj.sagepub.com

SMN1 gene, but not SMN2, is a risk factor for sporadic ALS

BACKGROUND

SMN1 gene deletions cause spinal muscular atrophy, and SMN2 gene deletions have been associated with sporadic lower motor neuron diseases.

OBJECTIVES

To study the frequency of abnormal SMN1 gene copy numbers and to determine whether SMN2 gene modulates the risk of amyotrophic lateral sclerosis (ALS) or the duration of evolution.

METHOD

The authors studied SMN1 and SMN2 genes in 600 patients with sporadic ALS and 621 controls using a quantitative PCR method.

RESULTS

The authors found an association of ALS with an abnormal copy number (one or three copies) of SMN1 gene (p < 0.0001) with an OR of 2.8 (1.8 to 4.4, 95% CI). There was no association with SMN2 copy numbers and no effect of SMN2 copies on the duration of evolution in ALS independently of SMN1 copy number.

CONCLUSION

Abnormal SMN1 gene copy numbers are a genetic risk factor in sporadic amyotrophic lateral sclerosis. There was no modulator effect of the SMN2 gene.

[Psychological treatment for the patient and caregivers during the course of amyotrophic lateral sclerosis]

Amyotrophic lateral sclerosis is a devastating disorder for which the psychological consequences of both the diagnosis announcement and the evolution of paralysis not only concern the patient but also his family. The role of the psychologist is to develop an individualized follow up considering the patient in his globality. The first consultation is, ideally, initiated after a medical consultation explaining the importance of the psychological area in ALS patient care. The psychological follow up will consist in an empathic listening of history and problems. Information will also be given to the patient by the psychologist who's role should not be only passive. When talking about "globality" of the psychological intervention for a given patient, his family takes a determinant place. The psychologist should be able to establish a contact with the family members concerned by the daily support to the patient. The psychological processes through which a patient will evolve should be explained to the family. Depression frequently affects family members, and a specific follow up in those cases has to be undertaken as soon as possible. Such a depressive reaction may also take place after death and a psychological follow up do not end after the death of a patient. The role of a psychologist in ALS care ideally takes places in the context of a multidisciplinary team such as a motoneuron clinic now largely available in our country. The burden of care is frequently heavy both for the family and the team of professional carers into and outside the hospital. The psychologist has a role of mediation between those persons, facilitating verbal exchanges, paying attention to specific difficulties and maintaining a fruitful exchange between the carers, the patient and his family. More prospectively, the psychologist also has a pedagogic role for the carers explaining psychological processes and giving clues for a constructive relationship between the patient and his family and also between this patient and his carers.

[What is the role of the genetic survey in amyotrophic lateral sclerosis?]

The genetic inquiry in the diagnostic process of amyotrophic lateral sclerosis (ALS) need to be precise and systematic. Several hereditary neurologic disorders may initially mimic ALS, such as dominant spino-cerebellar ataxia or spastic paraplegia. Other hereditary motor neuron disorders are clinically more difficult to distinct from ALS such as Kennedy's disease, adult-onset spinal muscular atrophies or juvenile ALS. When a final diagnostic of ALS is established, the genetic inquiry aims at identifying a familial ALS (FALS) case. Almost 10 to 20 percent of ALS cases are familial. It is now admitted that 10 to 20 percent of those cases are due to SOD1 gene mutations. Such mutations may have a dominant or recessive inheritance. They are mainly found in multigenerational families. In 80 percent of the FALS cases, only two ALS cases are found in the pedigree. One cannot know whether this represent dominant cases with low penetrance, recessive inheritance or a multigenic, hereditary complex, disorder. More other, not all the SOD1 mutations have been demonstrated as causal. These elements are strong enough to suggest to precisely study, in the presence of a given SOD1 mutation, both the clinical phenotype, the data from the literature and, as often as possible, the segregation of the mutation into the family, before ascertaining that the mutation is responsible for a hereditary case of ALS. In every case, the genetic inquiry together with its conclusions should be done with caution, taking into account both the patient's need of a clear information and his anxiety regarding his descent.