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Dystrophinopathies are muscle diseases caused by pathogenic variants in DMD, the largest gene described in humans, representing a spectrum of diseases ranging from asymptomatic creatine phosphokinase elevation to severe Duchenne muscular dystrophy (DMD). Several therapeutic strategies are currently in use or under development, each targeting different pathogenic variants. However, little is known about the genetic profiles of northeast Brazilian patients with dystrophinopathies. We describe the spectrum of pathogenic DMD variants in a single center in northeast Brazil. This is an observational, cross-sectional study carried out through molecular-genetic analysis of male patients diagnosed with dystrophinopathies using Multiplex Ligation-dependent Probe Amplification (MLPA) followed by Next-Generation Sequencing (NGS)-based strategies. A total of 94 male patients were evaluated. Deletions (43.6%) and duplications (10.6%) were the most recurring patterns of pathogenic variants. However, small variants were present in 47.1% of patients, most of them nonsense variants (27.6%). This is the largest South American single-center case series of dystrophinopathies to date. We found a higher frequency of treatment-amenable nonsense single-nucleotide variants than most previous studies. These findings may have implications for diagnostic strategies in less-known populations, as a higher frequency of nonsense variants may mean a higher possibility of treating patients with disease-modifying drugs. [ABSTRACT FROM AUTHOR]

Quarter horses (QH), a prominent athletic breed in Brazil, are affected by muscular genetic disorders such as myosin-heavy chain myopathy (MYHM), polysaccharide storage myopathy (PSSM1), hyperkalemic periodic paralysis (HyPP), and malignant hyperthermia (MH). Bull-catching (vaquejada), primarily involving QH, is a significant equestrian sport in Brazil. Since the allele frequencies (AF) of MYHM, PSSM1, HyPP, and MH in vaquejada QH remain unknown, this study evaluated the AF in 129 QH vaquejada athletes, specifically from the Brazilian Northeast. These variants were exclusively observed in heterozygosity. The MYHM exhibited the highest AF (0.04 ±0.01), followed by PSSM1 (0.01 ±0.01) and the HyPP variant (0.004 ±0.01), while the MH variant was not identified in this study. This study represents the first identification of these variants in vaquejada QH, emphasizing the need to implement measures to prevent the transmission of pathogenic alleles and reduce the occurrence of clinical cases of these genetic diseases., Competing Interests: Declaration of competing interest No competing interests have been declared., (Copyright © 2024 Elsevier Inc. All rights reserved.)

The epidemiological, clinical and pathological findings of field and experimental Senna obtusifolia (sicklepod; coffee senna) poisoning in cattle are described. The low availability of good quality forage and high rate of infestation of pastures by S. obtusifolia were the factors that led to poisonous plant ingestion. In this study, the morbidity ranged between 2% and 27.9%, and the lethality was 100%. For the experimental study, six cattle were fed with the aerial parts of S. obtusifolia collected in three different seasons at 9%–38% of the animal's body weight. The experimental and field diseases were similar. The main clinical signs were diarrhea, reluctance to move, muscular weakness and recumbency. The gross findings included pale discoloration of the skeletal muscle. Microscopically, the affected cattle showed degeneration and necrosis of the skeletal muscles and occasionally of the cardiac muscles. Additionally, two cattle showed centrilobular hepatic necrosis. In this study, S. obtusifolia collected from the same farm showed seasonal variation in toxicity. Poisoning by S. obtusifolia is an important cause of death of cattle in the Central Western region of Brazil. The toxicosis caused by this plant is similar to S. occidentalis poisoning; however, in S. obtusifolia poisoning, acute hepatic necrosis is sometimes present. [ABSTRACT FROM AUTHOR]

Abstract: Context: Chronic pain is a common complaint among patients with muscular disease. The Wisconsin Brief Pain Questionnaire (WBPQ) has been used to quantify pain severity and pain interference with daily functions. Objectives: To translate the WBPQ for use with Brazilian patients and to evaluate the psychometric properties of the adaptation. Methods: We conducted a cross-cultural adaptation of the original English version of the WBPQ for use in Brazil (WBPQ-B) and evaluated the psychometric properties of the adapted version. The original questionnaire was translated, evaluated by an expert panel, pilot tested in 40 patients, and back-translated. Subsequently, the tool was administered, in a cross-sectional study, to 100 adult patients who had muscular disease and were being attended to at our university hospital. Results: We performed a confirmatory factor analysis and assessed the reliability and validity of the questionnaire (Appendix). The two-factor structure (pain intensity and pain interference) was confirmed satisfactorily. Internal consistency for both scales was adequate (Cronbach's alpha = 0.74 and 0.79, respectively), as was the interrater stability (intraclass correlation coefficients = 0.88 and 0.92, respectively). Convergent validity with the 36-Item Short Form Health Survey was supported by confirmation of a priori hypotheses of negative and satisfactory correlations between the WBPQ-B and some of the 36-Item Short Form Health Survey domains. The pain interference scale correlated higher with the mental summary component. Known-group validity analysis showed that the pain intensity items and scale of the WBPQ-B were higher in the groups where patients with exercise intolerance were concentrated. Conclusion: We found the WBPQ-B to be a reliable and valid instrument for pain assessment of Brazilians who have muscular disease. The survey presents similar psychometric properties to the original version. [Copyright &y& Elsevier]

To identify environmental factors (EF) in a large cohort of patients with systemic sclerosis (SSc) analyzing their clinical and laboratory presentation. A cohort of consecutive patients attended at a single Brazilian SSc outpatient clinic was analyzed regarding EF. Data were analyzed according to clinical, demographic and laboratory characteristics, as well as SSc subtype. In a cohort of 662 patients, 70 (10.6%) had known previous exposure to EF, predominantly organic solvents (51.4%), silica (20%), silicone (12.9%) and pesticides (11.4%). In the SSc cohort, patients with EF had a significantly higher frequency of male gender (p < 0.01), African-Brazilian ethnicity (p = 0.01), myopathy (p = 0.02), and pigmentary disorders (p = 0.04), with shorter disease duration (p = 0.01). When SSc subtypes were analyzed separately, there was positive association with male gender in limited (p < 0.01) and diffuse (p < 0.01) SSc, as well as African-Brazilian ethnicity (p = 0.04), severe interstitial lung disease (p < 0.01), myopathy (p = 0.02) and SD pattern at nailfold capillaroscopy (p = 0.01) in limited SSc, and negative association with esophageal hypomotility (p < 0.01) and ANA positivity (p = 0.02) in diffuse SSc. Multiple regression analyses showed that myopathy was independently associated with previous exposure to EF (OR = 2.09; 95% CI 1.15-3.82), especially silica exposure (OR = 3.09; 95% CI 1.67-5.73). This study showed that SSc patients with previous exposure to EF may have some specific clinical characteristics, mainly a higher frequency of myopathy, also showing more severe ILD, preferably in male and African-Brazilian patients, associated with a lower frequency of ANA positivity.

Objectives: Collagen VI-related dystrophies (COL6-RDs) have a broad clinical spectrum and are caused by mutations in the COL6A1, COL6A2 and COL6A3 genes. Despite the clinical variability, two phenotypes are classically recognized: Bethlem myopathy (BM, milder form) and Ullrich congenital muscular dystrophy (UCMD, more severe form), with many patients presenting an intermediate phenotype. In this work, we present clinical and genetic data from 28 patients (27 families), aged 6-38 years (mean of 16.96 years), with COL6-RDs., Patients and Methods: Clinical, muscle histology and genetic data are presented. COL6A1, COL6A2 and COL6A3 genes were analyzed by next-generation sequencing (NGS)., Results: Homozygous or heterozygous variants were found in COL6A1 (12 families), COL6A2 (12 families) and COL6A3 (3 families). Patients with the severe UCMD phenotype (three cases) had a homogeneous clinical picture characterized by neonatal onset of manifestations, no gait acquisition and a stable course, but with severe respiratory involvement. Most of the patients with the mild UCMD phenotype had neonatal onset of manifestations (88.8 %), delayed motor development (66.6 %), slowly progressive course, pulmonary involvement (55.5 %) and loss of the walking capacity before the age of 10 (66.6 %). In the intermediate group (nine patients), some children had neonatal onset of manifestations (44.5 %) and delayed motor development (88.9 %); but all of them achieved the ability to walk and were still ambulatory. Some patients that had the BM phenotype presented neonatal manifestations (57.1 %); however, all of them had normal motor development and normal pulmonary function. Only one patient from the group of BM lost the walking capacity during the evolution of the disease. Other frequent findings observed in all groups were joint retractions, spinal deformities, distal hyperextensibility, congenital hip dislocation and keloid formation., Conclusion: COL6-RDs present variable clinical manifestations, but common findings are helpful for the clinical suspicion. NGS is a valuable approach for diagnosis, providing useful information for the genetic counseling of families., Competing Interests: Declaration of Competing Interest The authors declare that they have no conflict of interest., (Copyright © 2020 Elsevier B.V. All rights reserved.)