-
Orphanet Journal of Rare Diseases Jan 2021Oligosaccharidoses are storage disorders due to enzymatic defects involved in the breakdown of the oligosaccharidic component of glycosylated proteins. The defect cause...
BACKGROUND
Oligosaccharidoses are storage disorders due to enzymatic defects involved in the breakdown of the oligosaccharidic component of glycosylated proteins. The defect cause the accumulation of oligosaccharides (OS) and, depending on the lacking enzyme, results in characteristic profiles which are helpful for the diagnosis. We developed a new tandem mass spectrometry method for the screening of urinary OS which was applied to identify a large panel of storage disorders.
METHODS
The method was set-up in urine and dried urine spots (DUS). Samples were analysed, without derivatization and using maltoheptaose as internal standard, by UHPLC-MS/MS with MRM acquisition of target OS transitions, including Glc4, the biomarker of Pompe disease. The chromatographic run was < 30 min. Samples from patients with known storage disorders were used for clinical validation.
RESULTS
The method allowed to confirm the diagnosis of oligosaccharidoses (sialidosis, α-/β-mannosidosis, fucosidosis, aspartylglucosaminuria) and of GM1 and GM2 (Sandhoff type) gangliosidosis, by detecting specific OS profiles. In other storage disorders (mucolipidosis II and III, mucopolysaccharidosis type IVB) the analyisis revealed abnormal OS excretion with non-specific profiles. Besides Pompe disease, the tetrasaccharide Glc4 was increased also in disorders of autophagy (Vici syndrome, Yunis-Varon syndrome, and Danon disease) presenting cardiomuscular involvement with glycogen storage. Overall, results showed a clear separation between patients and controls, both in urine and in DUS.
CONCLUSION
This new UHPLC/MS-MS method, which is suitable for rapid and easy screening of OS in urine and DUS, expands the detection of storage disorders from oligosaccharidoses to other diseases, including the novel category of inherited disorders of autophagy.
Topics: Chromatography, High Pressure Liquid; Fucosidosis; Glycogen Storage Disease Type II; Humans; Lysosomal Storage Diseases; Oligosaccharides; Tandem Mass Spectrometry
PubMed: 33422100
DOI: 10.1186/s13023-020-01662-8 -
Molecular Genetics and Metabolism Mar 2021Despite profound neurological symptomatology there are only few MRI studies focused on the brain abnormalities in alpha-mannosidosis (AM). Our aim was to characterize...
OBJECTIVE
Despite profound neurological symptomatology there are only few MRI studies focused on the brain abnormalities in alpha-mannosidosis (AM). Our aim was to characterize brain MRI findings in a large cohort of AM patients along with clinical manifestations.
METHODS
Twenty-two brain MRIs acquired in 13 untreated AM patients (8 M/5F; median age 17 years) were independently assessed by three experienced readers and compared to 16 controls.
RESULTS
Focal and/or diffuse hyperintense signals in the cerebral white matter were present in most (85%) patients. Cerebellar atrophy was common (62%), present from the age of 5 years. Progression was observed in two out of 6 patients with follow-up scans. Cortical atrophy (62%) and corpus callosum thinning (23%) were already present in a 13-month-old child. The presence of low T signal intensity in basal ganglia and thalami was excluded by the normalized signal intensity profiling. The enlargement of perivascular spaces in white matter (38%), widening of perioptic CSF spaces (62%), and enlargement of cisterna magna (85%) were also observed. Diploic space thickening (100%), mucosal thickening (69%) and sinus hypoplasia (54%) were the most frequent non-CNS abnormalities.
CONCLUSION
White matter changes and cerebellar atrophy are proposed to be the characteristic brain MRI features of AM. The previously reported decreased T signal intensity in basal ganglia and thalami was not detected in this quantitative study. Rather, this relative MR appearance seems to be related to the diffuse high T signal in the adjacent white matter and not the gray matter iron deposition that has been hypothesized.
Topics: Adolescent; Adult; Atrophy; Brain; Cerebellum; Child; Child, Preschool; Female; Humans; Infant; Magnetic Resonance Imaging; Male; Nervous System Malformations; Neuroimaging; White Matter; Young Adult; alpha-Mannosidosis
PubMed: 33317989
DOI: 10.1016/j.ymgme.2020.11.008 -
Clinical Dysmorphology Apr 2021
Topics: Adult; Alleles; Child, Preschool; Consanguinity; DNA Mutational Analysis; Facies; Female; Fluorescein Angiography; Genetic Association Studies; Genetic Predisposition to Disease; Humans; Male; Mutation; Pedigree; Phenotype; Retinal Dystrophies; Symptom Assessment; alpha-Mannosidase; alpha-Mannosidosis
PubMed: 33290291
DOI: 10.1097/MCD.0000000000000361 -
Advances in Therapy Jan 2021Alpha-mannosidosis is a rare lysosomal storage disorder that generally presents in early childhood. It is a progressive, highly heterogeneous disease that is difficult...
Alpha-mannosidosis is a rare lysosomal storage disorder that generally presents in early childhood. It is a progressive, highly heterogeneous disease that is difficult to recognize, and a diagnosis is usually reached after referrals to multiple specialists. It is important to understand the challenges faced by patients and their caregiver up to and after a diagnosis of alpha-mannosidosis. In this report, we describe the process of alpha-mannosidosis diagnosis and treatment from the caregivers' and physicians' perspectives. For the caregivers' perspective, the mothers of two patients with alpha-mannosidosis ('Adele' aged 35 years and 'Amedeo' aged 40 years) were interviewed in their homes in Italy, and anonymized transcripts were used to describe their experiences. Adele lived in a large city with access to hospitals and specialized centers and was diagnosed with alpha-mannosidosis before 3 years of age. Amedeo was from a small village and was diagnosed when he was 10-11 years old. In both cases, their mothers sought help from pediatricians and other specialists for recurrent infections and delayed speech and motor development in the first years of their lives, but diagnosis was delayed. Although the diagnostic pathway was concerning and frustrating for her mother, Adele was able to live at home and receive multidisciplinary care and psychosocial support locally, but the transition from pediatric to adult services was difficult. She is currently waiting for access to enzyme replacement therapy. Amedeo had to travel widely and frequently to receive a diagnosis and access supportive treatment. The cumulative morbidity resulting from the delays and poor access to care necessitated long-term residential care. From the physicians' perspective, greater awareness of alpha-mannosidosis is required among healthcare professionals and more support is needed for patients and caregivers, particularly those living in rural areas or small centers.
Topics: Adult; Caregivers; Child; Child, Preschool; Female; Humans; Italy; Male; Physicians; alpha-Mannosidase; alpha-Mannosidosis
PubMed: 33231860
DOI: 10.1007/s12325-020-01574-w -
Orphanet Journal of Rare Diseases Sep 2020Alpha-mannosidosis is a lysosomal storage disorder caused by reduced enzymatic activity of alpha-mannosidase. SPARKLE is an alpha-mannosidosis registry intended to...
BACKGROUND
Alpha-mannosidosis is a lysosomal storage disorder caused by reduced enzymatic activity of alpha-mannosidase. SPARKLE is an alpha-mannosidosis registry intended to obtain long-term safety and effectiveness data on the use of velmanase alfa during routine clinical care in patients with alpha-mannosidosis. It is a post-approval commitment to European marketing authorization for Velmanase alfa (Lamzede), the first enzyme replacement therapy for the treatment of non-neurologic manifestations in patients with mild to moderate alpha-mannosidosis. In addition, SPARKLE will expand the current understanding of alpha-mannosidosis by collecting data on the clinical manifestations, progression, and natural history of the disease in treated and untreated patients, respectively.
RESULTS
The SPARKLE registry is designed as a multicenter, multinational, noninterventional, prospective cohort study of patients with alpha-mannosidosis, starting patient enrollment in 2020. Patients will be followed for up to 15 years. Safety and effectiveness as post-authorization outcomes under routine clinical care in patients with treatment will be evaluated. The primary safety outcomes are the rate of adverse events (anti-velmanase alfa-immunoglobulin G antibody development, infusion-related reactions, and hypersensitivity). Secondary safety outcomes include the evaluation of medical events, change in vital signs, laboratory tests, physical examination, and electrocardiogram results. The primary effectiveness outcome is a global treatment response rate, evaluated as the individual aggregate of single endpoints from pharmacodynamic, functional, and quality-of-life effectiveness outcomes; secondary effectiveness outcomes are to characterize the population of patients with alpha-mannosidosis with regard to clinical manifestation, progression, and natural history of the disease. Any patient in the European Union with a diagnosis of alpha-mannosidosis who is willing to participate will likely be eligible for inclusion in the registry. Publications to disseminate scientific insights from the registry are planned.
CONCLUSION
This study will provide real-world data on the long-term safety and effectiveness of velmanase alfa in patients with alpha-mannosidosis during routine clinical care and increase the understanding of the natural course, clinical manifestations, and progression of this ultra-rare disease.
Topics: Enzyme Replacement Therapy; Humans; Multicenter Studies as Topic; Prospective Studies; Registries; alpha-Mannosidase; alpha-Mannosidosis
PubMed: 32993743
DOI: 10.1186/s13023-020-01549-8 -
JIMD Reports Sep 2020Alpha mannosidosis is an ultrarare pathology with variable phenotypic manifestations, characterized by the deficiency of lysosomal alpha mannosidase which causes...
Alpha mannosidosis is an ultrarare pathology with variable phenotypic manifestations, characterized by the deficiency of lysosomal alpha mannosidase which causes accumulation of neutral oligosaccharides. Until recently, the hematopoietic stem cell transplantation was the only clinical feasible therapeutic option. Only in 2018, the European Medicines Agency's committee approved the recombinant enzyme velmanase alfa for long-term treatment of non-neurological manifestations in mild and moderate forms of alpha-mannosidosis. In this study, the very early biochemical effects of enzyme replacement therapy in in a 7-month-old patient with alpha-mannosidosis were described. Velmanase alpha was administered as supporting therapy awaiting for hematopoietic stem cell transplantation, the treatment chosen for the patient because of the early onset form. The results showed that the enzyme replacement therapy was able to reduce the content of three different mannosyl-oligosaccharides monitored by tandem mass spectrometry after 2 months of treatment. In particular, the mean relative changes from baseline values were -67% in urine and -53% in serum at the latest observation. The study also showed that the enzymatic activity detected in serum 1 week after the first infusion was four times higher than the normal values and constant in the following points of observation. These findings led us to assume that velmanase alfa might be biologically active in this young patient.
PubMed: 32905047
DOI: 10.1002/jmd2.12144 -
Brain : a Journal of Neurology Jul 2020Intravascular injection of certain adeno-associated virus vector serotypes can cross the blood-brain barrier to deliver a gene into the CNS. However, gene distribution...
Intravascular injection of certain adeno-associated virus vector serotypes can cross the blood-brain barrier to deliver a gene into the CNS. However, gene distribution has been much more limited within the brains of large animals compared to rodents, rendering this approach suboptimal for treatment of the global brain lesions present in most human neurogenetic diseases. The most commonly used serotype in animal and human studies is 9, which also has the property of being transported via axonal pathways to distal neurons. A small number of other serotypes share this property, three of which were tested intravenously in mice compared to 9. Serotype hu.11 transduced fewer cells in the brain than 9, rh8 was similar to 9, but hu.32 mediated substantially greater transduction than the others throughout the mouse brain. To evaluate the potential for therapeutic application of the hu.32 serotype in a gyrencephalic brain of larger mammals, a hu.32 vector expressing the green fluorescent protein reporter gene was evaluated in the cat. Transduction was widely distributed in the cat brain, including in the cerebral cortex, an important target since mental retardation is an important component of many of the human neurogenetic diseases. The therapeutic potential of a hu.32 serotype vector was evaluated in the cat homologue of the human lysosomal storage disease alpha-mannosidosis, which has globally distributed lysosomal storage lesions in the brain. Treated alpha-mannosidosis cats had reduced severity of neurological signs and extended life spans compared to untreated cats. The extent of therapy was dose dependent and intra-arterial injection was more effective than intravenous delivery. Pre-mortem, non-invasive magnetic resonance spectroscopy and diffusion tensor imaging detected differences between the low and high doses, and showed normalization of grey and white matter imaging parameters at the higher dose. The imaging analysis was corroborated by post-mortem histological analysis, which showed reversal of histopathology throughout the brain with the high dose, intra-arterial treatment. The hu.32 serotype would appear to provide a significant advantage for effective treatment of the gyrencephalic brain by systemic adeno-associated virus delivery in human neurological diseases with widespread brain lesions.
Topics: Animals; Brain; Cats; Dependovirus; Disease Models, Animal; Gene Transfer Techniques; Genetic Therapy; Genetic Vectors; Transduction, Genetic; alpha-Mannosidosis
PubMed: 32671406
DOI: 10.1093/brain/awaa161 -
Brain : a Journal of Neurology Jul 2020This scientific commentary refers to ‘Global CNS correction in a large brain model of human alpha-mannosidosis by intravascular gene therapy’, by Yoon...
This scientific commentary refers to ‘Global CNS correction in a large brain model of human alpha-mannosidosis by intravascular gene therapy’, by Yoon (doi:10.1093/brain/awaa161).
Topics: Animals; Brain; Brain Diseases; Genetic Therapy; Humans; Mice; alpha-Mannosidosis
PubMed: 32671401
DOI: 10.1093/brain/awaa189 -
Journal of the American Chemical Society Jul 2020Golgi mannosidase II (GMII) catalyzes the sequential hydrolysis of two mannosyl residues from GlcNAcManGlcNAc to produce GlcNAcManGlcNAc, the precursor for all complex...
Golgi mannosidase II (GMII) catalyzes the sequential hydrolysis of two mannosyl residues from GlcNAcManGlcNAc to produce GlcNAcManGlcNAc, the precursor for all complex -glycans, including the branched -glycans associated with cancer. Inhibitors of GMII are potential cancer therapeutics, but their usefulness is limited by off-target effects, which produce α-mannosidosis-like symptoms. Despite many structural and mechanistic studies of GMII, we still lack a potent and selective inhibitor of this enzyme. Here, we synthesized manno--cyclophellitol epoxide and aziridines and demonstrate their covalent modification and time-dependent inhibition of GMII. Application of fluorescent manno--cyclophellitol aziridine derivatives enabled activity-based protein profiling of α-mannosidases from both human cell lysate and mouse tissue extracts. Synthesized probes also facilitated a fluorescence polarization-based screen for dGMII inhibitors. We identified seven previously unknown inhibitors of GMII from a library of over 350 iminosugars and investigated their binding modalities through X-ray crystallography. Our results reveal previously unobserved inhibitor binding modes and promising scaffolds for the generation of selective GMII inhibitors.
Topics: Cyclohexanols; Drug Discovery; Enzyme Inhibitors; Humans; Mannosidases; Molecular Structure
PubMed: 32605368
DOI: 10.1021/jacs.0c03880 -
Cells Jun 2020The glycoprotein disorders are a group of lysosomal storage diseases (α-mannosidosis, aspartylglucosaminuria, β-mannosidosis, fucosidosis, galactosialidosis,... (Review)
Review
The glycoprotein disorders are a group of lysosomal storage diseases (α-mannosidosis, aspartylglucosaminuria, β-mannosidosis, fucosidosis, galactosialidosis, sialidosis, mucolipidosis II, mucolipidosis III, and Schindler Disease) characterized by specific lysosomal enzyme defects and resultant buildup of undegraded glycoprotein substrates. This buildup causes a multitude of abnormalities in patients including skeletal dysplasia, inflammation, ocular abnormalities, liver and spleen enlargement, myoclonus, ataxia, psychomotor delay, and mild to severe neurodegeneration. Pharmacological treatment options exist through enzyme replacement therapy (ERT) for a few, but therapies for this group of disorders is largely lacking. Hematopoietic cell transplant (HCT) has been explored as a potential therapeutic option for many of these disorders, as HCT introduces functional enzyme-producing cells into the bone marrow and blood along with the engraftment of healthy donor cells in the central nervous system (presumably as brain macrophages or a type of microglial cell). The outcome of HCT varies widely by disease type. We report our institutional experience with HCT as well as a review of the literature to better understand HCT and outcomes for the glycoprotein disorders.
Topics: Animals; Enzyme Replacement Therapy; Glycoproteins; Hematopoietic Stem Cell Transplantation; Humans; Lysosomal Storage Diseases
PubMed: 32517081
DOI: 10.3390/cells9061411