Genetic and Epidemiological Study of Adult Ataxia and Spastic Paraplegia in Eastern Quebec.

OBJECTIVE: To estimate the minimum prevalence of adult hereditary ataxias (HA) and spastic paraplegias (HSP) in Eastern Quebec and to evaluate the proportion of associated mutations in identified genes. METHODS: We conducted a descriptive cross-sectional study of patients who met clinical criteria for the diagnosis of HA (n = 241) and HSP (n = 115) in the East of the Quebec province between January 2007 and July 2019. The primary outcome was the prevalence per 100,000 persons with a 95% confidence interval (CI). The secondary outcome was the frequency of mutations identified by targeted next-generation sequencing (NGS) approach. Minimum carrier frequency for identified variants was calculated based on allele frequency values and the Hardy-Weinberg (HW) equation. RESULTS: The minimum prevalence of HA in Eastern Quebec was estimated at 6.47/100 000 [95% CI; 6.44-6.51]; divided into 3.73/100 000 for autosomal recessive (AR) ataxias and 2.67/100 000 for autosomal dominant (AD) ataxias. The minimum prevalence of HSP was 4.17/100 000 [95% CI; 4.14-4.2]; with 2.05/100 000 for AD-HSP and 2.12/100 000 for AR-HSP. In total, 52.4% of patients had a confirmed genetic diagnosis. AR cerebellar ataxia type 1 (2.67/100 000) and AD spastic paraplegia SPG4 (1.18/100 000) were the most prevalent disorders identified. Mutations were identified in 23 genes and molecular alterations in 7 trinucleotides repeats expansion; the most common mutations were c.15705-12 A > G in SYNE1 and c.1529C > T (p.A510V) in SPG7. CONCLUSIONS: We described the minimum prevalence of genetically defined adult HA and HSP in Eastern Quebec. This study provides a framework for international comparisons and service planning.

Molecular imaging in dementia: Past, present, and future.

Molecular imaging techniques using 18F-fluorodeoxyglucose, amyloid tracers, and, more recently, tau ligands have taken dementia research by storm and undoubtedly improved our understanding of neurodegenerative diseases. The ability to image in vivo the pathological substrates of degenerative diseases and visualize their downstream impact has led to improved models of pathogenesis, better differential diagnosis of atypical conditions, as well as focused subject selection and monitoring of treatment in clinical trials aimed at delaying or preventing the symptomatic phase of Alzheimer's disease. In this article, we present the main molecular imaging techniques used in research and practice. We further summarize the key findings brought about by each technique individually and more recently, as adjuncts to each other. Specific limitations of each imaging modality are discussed, as well as recommendations to overcome them. A nonvalidated clinical algorithm is proposed for earlier and more accurate identification of complex/atypical neurodegenerative diseases.

Autologous Hematopoietic Stem Cell Transplantation for Multiple Sclerosis, the Ottawa Protocol.

Autologous hematopoietic stem cell transplantation (aHSCT) is increasingly used to treat patients with highly active multiple sclerosis (MS) refractory to disease-modifying therapy. Briefly, cyclophosphamide and filgrastim are used to mobilize autologous hematopoietic stem cells (HSC) into the circulation. HSC are harvested by leukapheresis, purified using a CD34 immunomagnetic selection process, and cryopreserved. Busulphan, cyclophosphamide, and rabbit anti-thymocyte globulin are used to destroy the patient's autoreactive immune system, followed by infusion of the previously collected HSC, which reconstitute a naïve and self-tolerant immune system. Many MS patients experience durable remissions with no evidence of new disease activity following aHSCT. Treatment-related toxicity is rare, but potentially life-threatening complications necessitate appropriate patient selection by MS neurologists and HSCT physicians. AHSCT must be performed with a highly trained multidisciplinary team expert to minimize morbidity and mortality. We present the current aHSCT procedure for an MS indication at The Ottawa Hospital, developed from our program's 20-year experience. © 2022 Wiley Periodicals LLC. Basic Protocol 1: Candidate selection Basic Protocol 2: Autologous hematopoietic stem cell mobilization, collection, purification, and cryopreservation Basic Protocol 3: Autologous hematopoietic stem cell transplantation Basic Protocol 4: Supportive care following recovery from aHSCT (Beyond 100 days) Basic Protocol 5: Ongoing evaluation of multiple sclerosis.

The Occurrence of FUS Mutations in Pediatric Amyotrophic Lateral Sclerosis: A Case Report and Review of the Literature.

Amyotrophic lateral sclerosis (ALS) is a progressive motor neuron disease affecting both upper and lower motor neurons and leading to progressive paralysis. Most cases are sporadic, and the symptoms generally begin in the sixth or seventh decade. Juvenile ALS appears in a rare subgroup of patients with onset before the age of 25 years old. Contrary to the classical adult phenotype where 90% of cases are sporadic, most cases of juvenile ALS are caused by a genetic mutation in either SOD1 (superoxide dismutase one), SETX (senataxin), or FUS (fused in sarcoma). In the pediatric population, ALS is more infrequent and rarely considered in the differential diagnosis. There are few reports of ALS in children. Here, we describe a 14-year-old boy with a very fast progressing classical ALS phenotype and tremor caused by a c.1554_1557delACAG mutation in FUS. Our review of the literature advocates that pediatric ALS is highly suggestive of FUS mutations and that gene should be tested in children presenting with symptoms of ALS. The children with FUS-related ALS may have no family history and present initially with learning disabilities, tremor, and mild motor developmental delay.