👤 Joaquim M S Cabral

To investigate the moderating role of physical activity intensity and sedentary break patterns on the association between sedentary time (ST) and cardiometabolic risk in older adults. This cross-sectional study included 248 community-dwelling older adults without major cardiovascular diseases (66.0 ± 4.6 years; 78% female). Physical activity and ST were measured using a hip-worn accelerometer over seven consecutive days. Cardiometabolic disease risk was assessed using a sex-specific continuous metabolic syndrome score (cMetS). ST was entered as the explanatory variable for cMetS, while moderate-to-vigorous physical activity (MVPA), light physical activity (LPA), and the number of short (1-5 min) and long (>5 min) sedentary breaks were tested as moderators. All analyses were adjusted for traditional cardiometabolic risk factors and accelerometer wear time. MVPA (β = -0.005, p = 0.046), LPA (β = -0.030, p = 0.050), short (β = -0.003, p = 0.070) and long (β = -0.010, p = 0.011) sedentary breaks moderated the association between ST and cMetS. The Johnson-Neyman technique revealed that the association between ST and cMetS became non-significant (p ≥ 0.05) at thresholds of MVPA ≥ 19 min/day, LPA ≥ 5.9 h/day, short breaks ≥ 87/day, and long breaks ≥ 10/day. Our findings suggest that specific thresholds of MVPA and LPA, as well as short and long sedentary breaks may offset the deleterious association between ST and cardiometabolic risk in older adults. Show less

Complex diseases arise from the interplay of genetic and environmental factors. We present a case where complex diseases seem to coexist. A 12-month-old girl was referred for short stature and hypotonia. Initial evaluation revealed central hypothyroidism, growth hormone deficiency and a small pituitary gland with ectopic neurohypophysis. Replacement therapy improved growth, but developmental delay and strabismus ensued. At age 10, she experienced a first seizure treated with levetiracetam. At age 12, she presented diabetic ketoacidosis and functional insulin therapy was started; positive autoantibodies confirmed autoimmune etiology. Initial genetic testing performed by microarray analysis retrieved normal results, but exome sequencing revealed a heterozygous pathogenic variant in KANSL1 gene, allowing for the diagnosis of Koolen-de Vries syndrome. In this patient, Koolen-de Vries syndrome presented initially as hypopituitarism and only later epilepsy. Afterwards, type 1 diabetes mellitus ensued, highlighting the complexity of intertwined conditions. Show less

Hypertrophic cardiomyopathy (HCM) is the most prevalent inherited cardiomyopathy and a leading cause of sudden death. Genetic testing and familial cascade screening play a pivotal role in the clinical management of HCM patients. However, conventional genetic tests primarily focus on the detection of exonic and canonical splice site variation. Oversighting intronic non-canonical splicing variants potentially contributes to a proportion of HCM patients remaining genetically undiagnosed. Here, using a non-integrative reprogramming strategy, we generated induced pluripotent stem cell (iPSC) lines from four individuals carrying one of two variants within intronic regions of MYBPC3: c.1224-52G > A and c.1898-23A > G. Upon differentiation to iPSC-derived cardiomyocytes (iPSC-CMs), mis-spliced mRNAs were identified in cells harbouring these variants. Both abnormal mRNAs contained a premature termination codon (PTC), fitting the criteria for activation of nonsense mediated decay (NMD). However, the c.1898-23A > G transcripts escaped this mRNA quality control mechanism, while the c.1224-52G > A transcripts were degraded. The newly generated iPSC lines represent valuable tools for studying the functional consequences of intronic variation and for translational research aimed at reversing splicing abnormalities to prevent disease progression. Show less

Hypertrophic cardiomyopathy (HCM) is frequently caused by mutations in the MYPBC3 gene, which encodes the cardiac myosin-binding protein C (cMyBP-C). Most pathogenic variants in MYPBC3 are either nonsense mutations or result in frameshifts, suggesting that the primary disease mechanism involves reduced functional cMyBP-C protein levels within sarcomeres. However, a subset of MYPBC3 variants are missense mutations, and the molecular mechanisms underlying their pathogenicity remain elusive. Upon in vitro differentiation into cardiomyocytes, induced pluripotent stem cells (iPSCs) derived from HCM patients represent a valuable resource for disease modeling. In this study, we generated two iPSC lines from peripheral blood mononuclear cells (PBMCs) of a female with early onset and severe HCM linked to the MYBPC3: c.772G > A variant. Although this variant was initially classified as a missense mutation, recent studies indicate that it interferes with splicing and results in a frameshift. The generated iPSC lines exhibit a normal karyotype and display hallmark characteristics of pluripotency, including the ability to undergo trilineage differentiation. These novel iPSCs expand the existing repertoire of MYPBC3-mutated cell lines, broadening the spectrum of resources for exploring how diverse mutations induce HCM. They additionally offer a platform to study potential secondary genetic elements contributing to the pronounced disease severity observed in this individual. Show less

Familial hypertrophic cardiomyopathy (HCM) stands as a predominant heart condition, characterised by left ventricle hypertrophy in the absence of any associated loading conditions, with affected individuals having an increased risk of developing heart failure and sudden cardiac death (SCD). Two induced pluripotent stem cell (iPSC) lines were derived from peripheral blood mononuclear cells obtained from two unrelated individuals with previously reported nonsense mutations in the MYBPC3 gene. The first individual is a 48-year-old male (F26) with the MYBPC3 c.1731G > A HCM mutation, whereas the second individual is a 43-year-old female (F82) carrying the MYBPC3 c.2670G > A HCM mutation. The generated iPSCs exhibit appropriate expression of pluripotency markers, trilineage differentiation capacity and a normal karyotype. This resource contributes to gaining deeper insights into the pathophysiological mechanisms that underlie HCM. Show less

Familial hypertrophic cardiomyopathy (HCM) is the most common inherited heart condition. HCM patients show left ventricle hypertrophy without any associated loading conditions, being at risk for heart failure and sudden cardiac death. Two induced pluripotent stem cell (iPSC) lines were generated from peripheral blood mononuclear cells obtained from two unrelated individuals, a 54-year-old male (F81) and a 44-year-old female (F93), both carrying the MYBPC3 c.1484G>A HCM mutation. iPSCs show expression of pluripotency markers, trilineage differentiation capacity and a normal karyotype. This resource enables further assessment of the pathophysiological development of HCM. Show less

The neuronal ceroid-lipofuscinoses are the most common neurodegenerative disorders in childhood characterized by progressive blindness, epilepsy, brain atrophy, and premature death. Based on the age at onset, disease progression and ultrastructural features three classical (infantile, late-infantile, and juvenile) and three variant late-infantile forms are generally distinguished (Finnish variant, Costa Rican variant, and epilepsy with progressive motor retardation). The Finnish variant late-infantile form has been associated with CLN5 gene defects, with only five mutations described to date. We report a patient with vLINCL/CLN5 who represents the first evidence of the disease in the Portuguese population. Mutational screening revealed the previously described missense mutation c.835G>A (D279N) inherited from the mother, and two novel mutations, c.565C>T (Q189X) and c.335G>C (R112P) from paternal and maternal inheritance, respectively. Based on data here reported: (i) the number of possible mutations in CLN5 gene is now 7; (ii) the CLN5 Portuguese case represents the third description of the disease outside northern Europe; (iii) the CLN5/mRNA expression level reduced to 45% supports the existence of one mRNA non-producing allele, further noticeable at the protein level; (iv) Western blotting data using a specific antibody to human CLN5p provided evidence for the presence of four integral membrane isoforms in human fibroblasts; (v) data from differential expression of CLN2, CLN3, and CLN5 suggest down-regulation of CLN3 gene expression in CLN2 and CLN5-deficient human patients and this observation strengths the hypothesis of functional redundancy of the CLN system. Show less