Ataxia and Myoclonus with a Cherry-Red Spot Unfurling an Unusual Phenotypic Presentation of Sialidosis Type 1.
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ABSTRACT:
SUBMITTER: Mukherjee D
PROVIDER: S-EPMC8490189 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Sialidosis type 1 is a rare lysosomal storage disorder caused by mutations of the neuraminidase gene. Specific features suggesting this condition include myoclonus, ataxia and macular cherry-red spots. However, phenotypic variability exists. Here, we present detailed clinical and video description of three patients with this rare condition. We also provide an in-depth characterization of eye movement abnormalities, as an additional tool to investigate pathophysiological mechanisms and to facilitate diagnosis. In our patients, despite phenotypic differences, eye movement deficits largely localized to the cerebellum.
| S-EPMC8681143 | biostudies-literature
Project description:Sialidosis is an inborn error of metabolism due to a defect in the NEU1 gene and manifests as two phenotypes: mild type I and severe type II. The cherry red spot (CRS) is a characteristic feature in both types of sialidosis; reports of sialidosis without a CRS are rare. We report two cases of genetically confirmed sialidosis type I with a typical presentation of progressive cortical myoclonus and ataxia but without the CRS. A previously reported homozygous pathogenic variant p.Arg294Cys was detected in the first case, and a novel homozygous pathogenic variant p.Arg305Pro was detected in the second case. Additionally, we reviewed the literature describing cases with similar mutations to find a genetic basis for the absence of a CRS. Milder mutation of both alleles detected in both patients may be the reason for the absence of a CRS.
| S-EPMC7840231 | biostudies-literature
Project description:AimTo describe the ophthalmologic findings on the largest cohort of patients with sialidosis type I due to deficiency of the lysosomal sialidase, neuraminidase 1 (NEU1) and to introduce a quantitative neuroretinal image analysis approach to the associated 'macular cherry-red spot'.MethodsSeven patients with sialidosis type I (mutations in NEU1) and one with galactosialidosis (mutations in CTSA) were included. All patients underwent detailed ophthalmological examinations. The reflectivity of macular optical coherence tomography (OCT) was measured using greyscale analysis (Fiji) and compared with age-matched healthy volunteers. Four patients were evaluated over a time of 1.5+0.5 years.ResultsThe mean age of the patients at their first visit was 27.5+9.8 years. All patients had a macular cherry-red spot, clear corneas and visually non-significant lenticular opacities. The mean visual acuity was LogMar 0.4 (20/50)+0.4 (20/20 to 20/125). Six patients had good visual function. Optic atrophy was present in two individuals with reduced acuity. A significant increase in macular reflectivity was present in all patients compared to age-matched controls (p<0.0001).ConclusionMost of our patients (75%) have preserved visual acuity, even in adulthood. The presence of optic atrophy is associated with poor visual acuity. Increased macular reflectivity by OCT greyscale measurements is noted in all patients, although the underlying biological basis is unknown. These findings complement the current methods for examining and monitoring disease progression, especially in patients for whom visualisation of the cherry-red spot is not entirely clear.Trial registration numberNCT00029965.
| S-EPMC8142419 | biostudies-literature
Project description:Sialidosis is an autosomal recessive lysosomal storage disease caused by pathogenic variants in NEU1 which encodes lysosomal sialidase (neuraminidase 1). Lysosomal neuraminidase catalyzes the removal of terminal sialic acid molecules from glycolipids, glycoproteins and oligosaccharides. Sialidosis is classified into two types, based on phenotype and age of onset. Patients with the milder type 1 typically present late, usually in the second or third decade, with myoclonus, ataxia and visual defects. Type 2 is more severe and presents earlier with coarse facial features, developmental delay, hepatosplenomegaly and dysostosis multiplex. Presentation and severity of the disease are related to whether lysosomal sialidase is inactive or there is some residual activity. Diagnosis is suspected based on clinical features and increased urinary bound sialic acid excretion and confirmed by genetic testing showing pathogenic variants in NEU1. We report a patient with type 1 sialidosis who presented mainly with ataxia and both generalized and myoclonic seizures but no visual involvement. Whole exome sequencing of the proband detected compound heterozygous likely pathogenic variants (S182G and G227R) in NEU1.
| S-EPMC6047061 | biostudies-literature
Project description:BACKGROUND:Lysosomal storage diseases (LSD) often manifest with cherry red macular spots. Diagnosis is based on clinical features and specific biochemical and enzymatic patterns. In uncertain cases, genetic testing with next generation sequencing can establish a diagnosis, especially in milder or atypical phenotypes. We report on the diagnostic work-up in a boy with sialidosis type I, presenting initially with marked cherry red macular spots but non-specific urinary oligosaccharide patterns and unusually mild excretion of bound sialic acid. METHODS:Biochemical, enzymatic and genetic tests were performed in the patient. The clinical and electrophysiological data was reviewed and a genotype-phenotype analysis was performed. In addition a systematic literature review was carried out. CASE REPORT AND RESULTS:Cherry red macular spots were first noted at 6 years of age after routine screening myopia. Physical examination, psychometric testing, laboratory investigations as well as cerebral MRI were unremarkable at 9 years of age. So far no clinical myoclonic seizures occurred, but EEG displays generalized epileptic discharges and visual evoked potentials are prolonged bilaterally. Urine thin layer chromatography showed an oligosaccharide pattern compatible with different LSD including sialidosis, galactosialidosis, GM1 gangliosidosis or mucopolysaccharidosis type IV B. Urinary bound sialic acid excretion was mildly elevated in spontaneous and 24 h urine samples. In cultured fibroblasts, ?-sialidase activity was markedly decreased to < 1%; however, bound and free sialic acid were within normal range. Diagnosis was eventually established by multigene panel next generation sequencing of genes associated to LSD, identifying two novel, compound heterozygous variants in NEU1 gene (c.699C > A, p.S233R in exon 4 and c.803A > G; p.Y268C in Exon 5 in NEU1 transcript NM_000434.3), leading to amino acid changes predicted to impair protein function. DISCUSSION:Sialidosis should be suspected in patients with cherry red macular spots, even with non-significant urinary sialic acid excretion. Multigene panel next generation sequencing can establish a definite diagnosis, allowing for counseling of the patient and family.
| S-EPMC5137178 | biostudies-literature
Project description:BackgroundA myriad of disorders combine myoclonus and ataxia. Most causes are genetic and an increasing number of genes are being associated with myoclonus-ataxia syndromes (MAS), due to recent advances in genetic techniques. A proper etiologic diagnosis of MAS is clinically relevant, given the consequences for genetic counseling, treatment, and prognosis.ObjectivesTo review the causes of MAS and to propose a diagnostic algorithm.MethodsA comprehensive and structured literature search following PRISMA criteria was conducted to identify those disorders that may combine myoclonus with ataxia.ResultsA total of 135 causes of combined myoclonus and ataxia were identified, of which 30 were charted as the main causes of MAS. These include four acquired entities: opsoclonus-myoclonus-ataxia syndrome, celiac disease, multiple system atrophy, and sporadic prion diseases. The distinction between progressive myoclonus epilepsy and progressive myoclonus ataxia poses one of the main diagnostic dilemmas.ConclusionsDiagnostic algorithms for pediatric and adult patients, based on clinical manifestations including epilepsy, are proposed to guide the differential diagnosis and corresponding work-up of the most important and frequent causes of MAS. A list of genes associated with MAS to guide genetic testing strategies is provided. Priority should be given to diagnose or exclude acquired or treatable disorders.
| S-EPMC7780951 | biostudies-literature
Project description:BACKGROUND:Cortical myoclonus with ataxia has only rarely been reported in association with Coeliac Disease (CD). Such reports also suggested that it is unresponsive to gluten-free diet. We present detailed electro-clinical characteristics of a new syndrome of progressive cortical hyperexcitability with ataxia and refractory CD. At our gluten/neurology clinic we have assessed and regularly follow up over 600 patients with neurological manifestations due to gluten sensitivity. We have identified 9 patients with this syndrome. RESULTS:All 9 patients (6 male, 3 female) experienced asymmetrical irregular myoclonus involving one or more limbs and sometimes face. This was often stimulus sensitive and became more widespread over time. Three patients had a history of Jacksonian march and five had at least one secondarily generalised seizure. Electrophysiology showed evidence of cortical myoclonus. Three had a phenotype of epilepsia partialis continua at onset. There was clinical, imaging and/or pathological evidence of cerebellar involvement in all cases. All patients adhered to a strict gluten-free diet with elimination of gluten-related antibodies in most. However, there was still evidence of enteropathy in all, suggestive of refractory celiac disease. Two died from enteropathy-associated lymphoma and one from status epilepticus. Five patients were treated with mycophenolate and one in addition with rituximab and IV immunoglobulins. Their ataxia and enteropathy improved but myoclonus remained the most disabling feature of their illness. CONCLUSIONS:This syndrome may well be the commonest neurological manifestation of refractory CD. The clinical involvement, apart from ataxia, covers the whole clinical spectrum of cortical myoclonus.
| S-EPMC4552176 | biostudies-literature
Project description: Not available
| S-EPMC7436437 | biostudies-literature
Project description:Neurological manifestations of coronavirus disease (COVID-19) have increasingly been reported since the onset of the pandemic. Herein, we report a relatively new presentation. A patient in the convalescence period following a febrile illness with lower respiratory tract infection (fever, myalgia, nonproductive cough) presented with generalized disabling myoclonus, which is phenotypically suggestive of brainstem origin, along with additional truncal cerebellar ataxia. His neurology work-ups, such as brain MRI, electroencephalography, serum autoimmune and paraneoplastic antibody testing, were normal. His CT chest scan revealed right lower lung infiltrates, and serological and other laboratory testing did not show evidence of active infection. COVID-19 titers turned out to be strongly positive, suggestive of post-COVID-19 lung sequelae. He responded partially to antimyoclonic drugs and fully to a course of steroids, suggesting a para- or postinfectious immune-mediated pathophysiology. Myoclonusataxia syndrome appears to be a neurological manifestation of COVID-19 infection, and knowledge regarding this phenomenon should be increased among clinicians for better patient care in a pandemic situation.
| S-EPMC8175811 | biostudies-literature
Project description:Background:Spinocerebellar ataxia type 23 (SCA23) is an autosomal dominant cerebellar ataxia caused by pathogenic variants in the prodynorphin gene (PDYN). The frequency of PDYN variants is reportedly very low (~?0.1%) in several ataxia cohorts screened to date. Case presentations:We found five cases of SCA23 in two families (mean age at onset: 37.8?±?5.5?years; mean age at examination: 64.2?±?12.3?years) with a novel PDYN variant (c.644G?>?A:p.R215H). We identified marked heterogeneity in the clinical features in Family 1: the proband showed clinical and neuroimaging features suggestive of multiple system atrophy with predominant parkinsonism (MSA-P). Conversely, the proband's mother with the PDYN p.R215H variant had no subjective symptoms; she had not come to medical attention before our survey, although she showed apparent cerebellar atrophy on brain magnetic resonance imaging (MRI). The other two patients in Family 1 and a patient in Family 2 showed slowly progressive cerebellar ataxia. Conclusions:We here report two Japanese families with SCA23, one of which showed considerable phenotypic variation in affected members. Our findings support that SCA23 can phenotypically overlap with MSA.
| S-EPMC7310450 | biostudies-literature