Publications by authors named "Alexander Lossos"

In this Correspondence, B. Minassian and colleagues report that GHF201, an autophagy activator shown to diminish abnormal glycogen aggregates in a mouse model of Adult Polyglucosan Body Disease, fails to reduce such accumulations in a mouse model of Lafora disease. [Image: see text]

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Background: Radiotherapy has an important role in the treatment of brain metastases but carries risk of short and/or long-term toxicity, termed radiation-induced brain injury (RBI). As the diagnosis of RBI is crucial for correct patient management, there is an unmet need for reliable biomarkers for RBI. The aim of this proof-of concept study is to determine the utility of brain-derived circulating free DNA (BncfDNA), identified by specific methylation patterns for neurons, astrocytes, and oligodendrocytes, as biomarkers brain injury induced by radiotherapy.

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Unlabelled: Immune checkpoint inhibition (ICI) is effective for replication-repair-deficient, high-grade gliomas (RRD-HGG). The clinical/biological impact of immune-directed approaches after failing ICI monotherapy is unknown. We performed an international study on 75 patients treated with anti-PD-1; 20 are progression free (median follow-up, 3.

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Background: We report a rare case of ipsilateral multiple cranial neuropathy and ipsilateral lymphadenopathy following mRNA-COVID-19 vaccination.

Case Presentation: A 41-year-old male visited our emergency room complaining of dysphagia and hoarseness that started a week after receiving COVID19 mRNA vaccination (in his right arm). During his hospitalization, he also complained of right side hearing loss and diplopia.

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The management of primary central nervous system (PCNSL) is one of the most controversial topics in neuro-oncology because of the complexity of the disease and the limited number of controlled studies available. In 2021, given recent advances and the publication of practice-changing randomized trials, the European Association of Neuro-Oncology (EANO) created a multidisciplinary task force to update the previously published evidence-based guidelines for immunocompetent adult patients with PCNSL and added a section on immunosuppressed patients. The guideline provides consensus considerations and recommendations for the treatment of PCNSL, including intraocular manifestations and specific management of the elderly.

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Background: Monogenic neurodegenerative diseases represent a heterogeneous group of disorders caused by mutations in genes involved in various cellular functions including autophagy, which mediates degradation of cytoplasmic contents by their transport into lysosomes. Abnormal autophagy is associated with hereditary ataxia and spastic paraplegia, amyotrophic lateral sclerosis and frontal dementia, characterised by intracellular accumulation of non-degraded proteins. We investigated the genetic basis of complex HSP in a consanguineous family of Arab-Muslim origin, consistent with autosomal recessive inheritance.

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Article Synopsis
  • - AOA2 is a rare disease in adolescents, marked by symptoms like brain atrophy, nerve damage, and high alpha-fetoprotein levels, caused by mutations in the SETX gene related to DNA repair and RNA function.
  • - Gene sequencing in two families identified new mutations in the SETX gene, which were linked to increased chromosome damage and higher sensitivity to oxidative stress, showcasing the impact of these mutations on cellular health.
  • - The findings suggest a broader range of clinical symptoms for AOA2 and hint at new therapeutic strategies due to the discovery of a potential "poison exon" in the SETX gene, which might help in creating customized treatments.
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The optimal high-dose methotrexate (HDMTX)-based combination therapy for primary central nervous system lymphoma is unknown. We report our experience with rituximab, HDMTX, procarbazine and lomustine (R-MPL) given as first-line treatment in our center. Fifty-two patients between 2006 and 2019 were included.

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Objective: Human genomics established that pathogenic variation in diverse genes can underlie a single disorder. For example, hereditary spastic paraplegia is associated with >80 genes, with frequently only few affected individuals described for each gene. Herein, we characterize a large cohort of individuals with biallelic variation in ENTPD1, a gene previously linked to spastic paraplegia 64 (Mendelian Inheritance in Man # 615683).

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Article Synopsis
  • * A study involving 45 tumors from 38 patients indicated that immune checkpoint inhibitors (ICIs) can lead to improved survival rates, especially in tumors with ultra-high mutation rates or specific genetic characteristics.
  • * The research highlights the importance of mutation burden and microsatellite instability (MS-indels) in predicting ICI treatment responses, showing that even tumors typically classified as non-responsive can benefit from this type of immunotherapy.
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  • SCLC (Small Cell Lung Cancer) is linked to paraneoplastic syndromes like dermatomyositis, which is marked by specific autoantibodies, particularly anti-TIF1-γ.
  • A case study reveals a patient with SCLC and dermatomyositis who tested positive for the anti-TIF1-γ antibody and had a point mutation in the TIF1-γ gene.
  • The patient showed a significant clinical response to chemoradiation, leading to the suggestion that the identified mutation is pathogenic and contributes to the development of malignancy-associated dermatomyositis through immune cross-reactivity.
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This work employs adult polyglucosan body disease (APBD) models to explore the efficacy and mechanism of action of the polyglucosan-reducing compound 144DG11. APBD is a glycogen storage disorder (GSD) caused by glycogen branching enzyme (GBE) deficiency causing accumulation of poorly branched glycogen inclusions called polyglucosans. 144DG11 improved survival and motor parameters in a GBE knockin (Gbe ) APBD mouse model.

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We report a multiplex family with extended multisystem neurological phenotype associated with a CRYAB variant. Two affected siblings were evaluated with whole exome sequencing, muscle biopsy, laser microdissection, and mass spectrometry-based proteomic analysis. Both patients and their mother manifested a combination of early-onset cataracts, cardiomyopathy, cerebellar ataxia, optic atrophy, cognitive impairment, and myopathy.

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Background: G lioblastoma (GBM) is associated with poor overall survival. Recently, we showed that androgen receptor (AR) protein is overexpressed in 56% of GBM specimens and AR antagonists induced dose-dependent death in several GBM cell lines and significantly reduced tumor growth and prolonged the lifespan of mice implanted with human GBM. 16β-18F-fluoro-5α-dihydrotestosterone ([F]-FDHT) is a positron emission tomography (PET) tracer used to detect AR expression in prostate and breast cancers.

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POLR3A encodes the largest subunit of the DNA-dependent RNA polymerase III. Pathogenic variants in this gene are associated with dysregulation of tRNA production and other non-coding RNAs. POLR3A-related disorders include variable phenotypes.

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Objective: Von Hippel-Lindau (VHL) syndrome is a rare and complex disease. In 1996, we described a 3 generation VHL 2A kindred with 11 mutation carriers. We aim to share our experience regarding the long-term follow-up of this family and the management of all our other VHL patients focusing on frequently encountered neuroendocrine neoplasms: pheochromocytoma/paraganglioma and pancreatic neuroendocrine neoplasms (PNEN).

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Article Synopsis
  • Replication repair deficiency, resulting from mismatch repair deficiency (MMRD) and/or loss of DNA polymerase proofreading, leads to hypermutation in cancer, with microsatellite instability (MSI) being a key indicator of MMRD.
  • Genome-wide analysis reveals a connection between loss of polymerase proofreading and MSI, particularly when both replication repair mechanisms are compromised, highlighting distinct mutation signatures (MS-sigs).
  • The study emphasizes the clinical utility of MS-sigs in identifying replication repair deficiencies in cancer patients and predicting their responses to immunotherapy, enhancing diagnosis and treatment strategies.
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Background: Lymphoma of the nervous system is rare and usually involves the brain, spinal cord, or peripheral nerves. Hence, it has varied clinical presentations, and correct diagnosis is often challenging. Incorrect diagnosis delays the appropriate treatment and affects prognosis.

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Replication repair deficiency (RRD) leading to hypermutation is an important driving mechanism of high-grade glioma (HGG) occurring predominantly in the context of germline mutations in RRD-associated genes. Although HGG presents specific patterns of DNA methylation corresponding to oncogenic mutations, this has not been well studied in replication repair-deficient tumors. We analyzed 51 HGG arising in the background of gene mutations in RRD utilizing either 450 k or 850 k methylation arrays.

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Purpose Of Review: Until recently, the gene associated with the recessive form of familial brain calcification (PFBC, Fahr disease) was unknown. MYORG, a gene that causes recessive PFBC was only recently discovered and is currently the only gene associated with a recessive form of this disease. Here, we review the radiological and clinical findings in adult MYORG mutation homozygous and heterozygous individuals.

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Objective: To investigate the genetic basis of the recessive form of primary familial brain calcification and study pathways linking a novel gene with known dominant genes that cause the disease.

Methods: Whole exome sequencing and Sanger-based segregation analysis were used to identify possible disease causing mutations. Mutation pathogenicity was validated by structural protein modeling.

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Adult polyglucosan body disease (APBD) is a late-onset disease caused by intracellular accumulation of polyglucosan bodies, formed due to glycogen-branching enzyme (GBE) deficiency. To find a treatment for APBD, we screened 1,700 FDA-approved compounds in fibroblasts derived from APBD-modeling GBE1-knockin mice. Capitalizing on fluorescent periodic acid-Schiff reagent, which interacts with polyglucosans in the cell, this screen discovered that the flavoring agent guaiacol can lower polyglucosans, a result also confirmed in APBD patient fibroblasts.

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