Anoctamin-5 related muscle disease: clinical and genetic findings in a large European cohort.

Anoctamin-5 related muscle disease is caused by biallelic pathogenic variants in the anoctamin-5 gene (ANO5) and shows variable clinical phenotypes: limb-girdle muscular dystrophy type 12 (LGMD-R12), distal muscular dystrophy type 3 (MMD3), pseudometabolic myopathy or asymptomatic hyperCKaemia. In this retrospective, observational, multicentre study we gathered a large European cohort of patients with ANO5-related muscle disease to study the clinical and genetic spectrum and genotype-phenotype correlations. We included 234 patients from 212 different families, contributed by 15 centres from 11 European countries. The largest subgroup was LGMD-R12 (52.6%), followed by pseudometabolic myopathy (20.5%), asymptomatic hyperCKaemia (13.7%) and MMD3 (13.2%). In all subgroups, there was a male predominance, except for pseudometabolic myopathy. Median age at symptom onset of all patients was 33 years (range 23-45 years). The most frequent symptoms at onset were myalgia (35.3%) and exercise intolerance (34.1%), while at last clinical evaluation most frequent symptoms and signs were proximal lower limb weakness (56.9%) and atrophy (38.1%), myalgia (45.1%) and atrophy of the medial gastrocnemius muscle (38.4%). Most patients remained ambulatory (79.4%). At last evaluation, 45.9% of patients with LGMD-R12 additionally had distal weakness in the lower limbs and 48.4% of patients with MMD3 also showed proximal lower limb weakness. Age at symptom onset did not differ significantly between males and females. However, males had a higher risk of using walking aids earlier (P = 0.035). No significant association was identified between sportive versus non-sportive lifestyle before symptom onset and age at symptom onset nor any of the motor outcomes. Cardiac and respiratory involvement that would require treatment occurred very rarely. Ninety-nine different pathogenic variants were identified in ANO5 of which 25 were novel. The most frequent variants were c.191dupA (p.Asn64Lysfs*15) (57.7%) and c.2272C>T (p.Arg758Cys) (11.1%). Patients with two loss-of function variants used walking aids at a significantly earlier age (P = 0.037). Patients homozygous for the c.2272C>T variant showed a later use of walking aids compared to patients with other variants (P = 0.043). We conclude that there was no correlation of the clinical phenotype with the specific genetic variants, and that LGMD-R12 and MMD3 predominantly affect males who have a significantly worse motor outcome. Our study provides useful information for clinical follow up of the patients and for the design of clinical trials with novel therapeutic agents.

Tissue donations for multiple sclerosis research: current state and suggestions for improvement.

Although major progress in multiple sclerosis research has been made during the last decades, key questions related to the cause and the mechanisms of brain and spinal cord pathology remain unresolved. These cover a broad range of topics, including disease aetiology, antigenic triggers of the immune response inside and/or outside the CNS and mechanisms of inflammation, demyelination neurodegeneration and tissue repair. Most of these questions can be addressed with novel molecular technologies in the injured CNS. Access to brain and spinal cord tissue from multiple sclerosis patients is, therefore, of critical importance. High-quality tissue is provided in part by the existing brain banks. However, material from early and highly active disease stages is limited. An initiative, realized under the patronage of the European Charcot Foundation, gathered together experts from different disciplines to analyse the current state of multiple sclerosis tissues collected post-mortem or as biopsies. Here, we present an account of what material is currently available and where it can be accessed. We also provide recommendations on how tissue donation from patients in early disease stages could be potentially increased and for procedures of tissue sampling and preservation. We also suggest to create a registry of the available tissues that, depending on the source (autopsy versus biopsy), could be made accessible to clinicians and researchers.

Clinical spectrum of the anti-GQ1b antibody syndrome: a case series of eight patients.

Anti-GQ1b antibodies can be detected in the serum of patients with Miller Fisher syndrome (MFS) and its incomplete forms such as acute ophthalmoparesis (AO), acute ptosis, acute mydriasis, acute oropharyngeal palsy and acute ataxic neuropathy (AAN), as well as in pharyngeal-cervical-brachial weakness, Bickerstaff brainstem encephalitis (BBE) and in overlap syndromes with Guillain-Barré syndrome (MFS-GBS, BBE-GBS). We searched the laboratory medicine database at University Hospitals Leuven between 2002 and 2017 for serum samples with anti-GQ1b IgG antibodies. We identified eight patients with anti-GQ1b antibodies: 4 MFS, 2 AO, 1 MFS-GBS and 1 AAN. Mean age was 57 years and five patients were males. Preceding illness was present in all patients. At nadir, we observed most frequently gait disturbance, external ophthalmoplegia and absent/decreased reflexes. Albumino-cytological dissociation was present in four patients. Mean time between onset and nadir was 4 days, between onset and recovery 2.5 months. Five patients recovered completely and three had minor residual symptoms. Interestingly, one patient with AO experienced a second identical episode, approximately 1 year after the first one. Our data confirm the broad clinical spectrum associated with the presence of anti-GQ1b IgG antibodies. Incomplete MFS subtypes such as AO are a challenge for diagnosis, because of the limited (though invalidating) clinical presentation and the lack of confirming ancillary tests. Subacute onset of ophthalmoplegia and/or ataxia should urge the clinician to include the anti-GQ1b antibody syndrome in the differential diagnosis.