Publications by authors named "Marcela Machado Costa"

Background: Transthyretin amyloidosis (ATTR) is an infiltrative disease caused by abnormal protein deposition mainly in the heart and peripheral nervous system. When it affects the heart, the disease presents as restrictive cardiomyopathy; when it affects the peripheral and autonomic nervous system, it manifests as polyneuropathy, and is called familial amyloid polyneuropathy (FAP). There are two ATTR subtypes: wild-type ATTR, where there is no mutation, and mutant ATTR (ATTRm), which is characterized by a mutation in the gene encoding the transthyretin protein (TTR).

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Spinal muscular atrophy linked to chromosome 5 (SMA-5q) is an autosomal recessive genetic disease caused by mutations in the . SMA-5q is characterized by progressive degeneration of the spinal cord and bulbar motor neurons, causing severe motor and respiratory impairment with reduced survival, especially in its more severe clinical forms. In recent years, highly effective disease-modifying therapies have emerged, either acting by regulating the splicing of exon 7 of the gene or adding a copy of the gene through gene therapy, providing a drastic change in the natural history of the disease.

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Article Synopsis
  • * Treatment options have improved significantly; liver transplantation has been available since 1990, and there are now at least three approved drugs in various countries, including Brazil.
  • * In June 2017, Brazil held its first consensus meeting on ATTRv-PN, and a second edition was organized in light of recent developments, involving a group of experts who reviewed and updated previous findings.
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Background: Amyotrophic lateral sclerosis (ALS) is a degenerative disease of the nervous system that primarily affects motor neurons. ALS type 8 (ALS8) is a familiar form with predominant involvement of lower motor neurons, tremor, and slow progression.

Objective: The aim of this study was to describe sensory involvement in a cohort of ALS8 patients and compare it with the characteristics of sporadic ALS (sALS) patients and controls.

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Nemaline myopathy (NM), a structural congenital myopathy, presents a significant clinical and genetic heterogeneity. Here, we compiled molecular and clinical data of 30 Brazilian patients from 25 unrelated families. Next-generation sequencing was able to genetically classify all patients: sixteen families (64%) with mutation in NEB, five (20%) in ACTA1, two (8%) in KLHL40, and one in TPM2 (4%) and TPM3 (4%).

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The involvement of cranial nerves is rare in ATTR amyloidosis. However, involvement has occasionally been reported in the p.Val50Met variant, the most commonly studied worldwide.

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Article Synopsis
  • The study aimed to analyze the genetic variations in the survival motor neuron 1 (SMN1) gene among Brazilian patients with spinal muscular atrophy (SMA) and to connect these variants with disease severity.
  • Out of 450 patients, the majority (89.3%) had a common deletion in exon 7, while others had a mix of this deletion and additional point mutations, with certain variants being more prevalent in compound heterozygous cases.
  • The research concluded that specific variants (c.460C>T and c.5C>G) were linked to milder disease forms, and that the copy number of the gene did not consistently predict disease severity among these patients.*
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Amyloidosis, caused by a mutation in the transthyretin (TTR) gene, is the most common hereditary type disease. More than 120 mutations have been described, with extensive phenotypic heterogeneity. Val30Met (p.

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Objective: ANO5-related myopathy is an important cause of limb-girdle muscular dystrophy (LGMD) and hyperCKemia. The main descriptions have emerged from European cohorts, and the burden of the disease worldwide is unclear. We provide a detailed characterization of a large Brazilian cohort of ANO5 patients.

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Limb-girdle muscular dystrophies (LGMD) are a group of genetically heterogeneous disorders characterized by predominantly proximal muscle weakness. We aimed to characterize epidemiological, clinical and molecular data of patients with autosomal recessive LGMD2/LGMD-R in Brazil. A multicenter historical cohort study was performed at 13 centers, in which index cases and their affected relatives' data from consecutive families with genetic or pathological diagnosis of LGMD2/LGMD-R were reviewed from July 2017 to August 2018.

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Amyotrophic lateral sclerosis (ALS) is an incurable neuromuscular disease that leads to a profound loss of life quality and premature death. Around 10% of the cases are inherited and ALS8 is an autosomal dominant form of familial ALS caused by mutations in the vamp-associated protein B/C (VAPB) gene. The VAPB protein is involved in many cellular processes and it likely contributes to the pathogenesis of other forms of ALS besides ALS8.

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