Phenotypic Variability of Andersen-Tawil Syndrome Due to Allelic Mutation c.652C>T in the KCNJ2 Gene-A New Family Case Report.

Andersen-Tawil syndrome (ATS) is a multisystem channelopathy characterized by periodic paralysis, ventricular arrhythmias, prolonged QT interval, and facial dysmorphisms occurring in the first/second decade of life. High phenotypic variability and incomplete penetrance of the genes causing the disease make its diagnosis still a challenge. We describe a three-generation family with six living individuals affected by ATS. The proband is a 37-year-old woman presenting since age 16, with episodes of muscle weakness and cramps in the pre-menstrual period. The father, two brothers, one paternal uncle and one cousin also complained of cramps, muscle stiffness, and weakness. Despite normal serum potassium concentration, treatment with potassium, magnesium, and acetazolamide alleviated paralysis attacks suggesting a dyskalemic syndrome. Dysmorphic features were noted in the proband, only later. On the ECG, all but one had normal QT intervals. The affected males developed metabolic syndrome or obesity. The father had two myocardial infarctions and was implanted with an intracardiac cardioverter defibrillator (ICD). A genetic investigation by WES analysis detected the heterozygous pathogenic variant (NM_000891.2: c.652C>T, p. Arg218Trp) in the KCNJ2 gene related to ATS, confirmed by segregation studies in all affected members. Furthermore, we performed a review of cases with the same mutation in the literature, looking for similarities and divergences with our family case.

Potential of Lipid Biosynthesis under Heterotrophy in the Marine Diatom Cyclotella cryptica.

Despite the theoretical high productivity, microalgae-based oil production is not economically sustainable due to the high cost of photoautotrophic cultures. Heterotrophic growth is a suitable economic alternative to overcoming light dependence and climatic/geographic fluctuations. Here we report data about growth performance, biomass production, and lipid composition of the marine diatom Cyclotella cryptica, chosen as a model strain for biodiesel production in heterothrophy. A repeated-batch process of heterotrophic cultivation has also been investigated to assess the robustness and phenotypic stability. The process consisting of six constant cycle repetitions was carried out for 42 days and led to an average dry biomass production of 1.5 ± 0.1 g L-1 of which 20% lipids composed of 60% triglycerides, 20% phospholipids. and 20% glycolipids. The major fatty acids were C16:0 (∼26%), C16:1 ω-7 (∼57%), and C20:5 ω-3 (∼12%), with a significant reduction in the unsaturated fatty acids in comparison to other microalgae grown in heterotrophy. Fatty acids were differently distributed among the glycerolipid classes, and the lipid composition was used to compare the potential properties of C. cryptica oil with traditional vegetable biofuels.

The Role of TRPM4 Gene Mutations in Causing Familial Progressive Cardiac Conduction Disease: A Further Contribution.

Progressive cardiac conduction disease (PCCD) is a relatively common condition in young and elderly populations, related to rare mutations in several genes, including SCN5A, SCN1B, LMNA and GJA5, TRPM4. Familial cases have also been reported. We describe a family with a large number of individuals necessitating pacemaker implantation, likely due to varying degrees of PCCD. The proband is a 47-year-old-patient, whose younger brother died at 25 years of unexplained sudden cardiac death. Three paternal uncles needed a pacemaker (PM) implantation between 40 and 65 years for unspecified causes. At the age of 42, he was implanted with a PM for two episodes of syncope and the presence of complete atrioventricular block (AVB). NGS analysis revealed the missense variation c. 2351G>A, p.Gly844Asp in the exon 17 of the TRPM4 gene. This gene encodes the TRPM4 channel, a calcium-activated nonselective cation channel of the transient receptor potential melastatin (TRPM) ion channel family. Variations in TRPM4 have been shown to cause an increase in cell surface current density, which results in a gain of gene function. Our report broadens and supports the causative role of TRPM4 gene mutations in PCCD. Genetic screening and identification of the causal mutation are critical for risk stratification and family counselling.

Autotrophic vs. Heterotrophic Cultivation of the Marine Diatom Cyclotella cryptica for EPA Production.

Recently, the marketable value of ω-3 fatty acid, particularly eicosapentaenoic acid (EPA), increased considering their health effects for human consumption. Microalgae are considered a valuable and "green" source of EPA alternative to fish oils, but considerable efforts are necessary for their exploitation at an industrial level. Due to the high operation costs of photoautotrophic microalgae cultivation, heterotrophic growth represents a promising economic solution. Marine diatoms are the major ecological producers of ω-3 fatty acids. Few species of diatoms are capable to grow in the dark using organic carbon sources. The marine diatom Cyclotella cryptica was cultivated for 14 days under photoautotrophic and heterotrophic conditions to define the effects on growth parameters, lipid production, total fatty acids and EPA content. Photoautotrophic conditions led to a total EPA production of 1.6% of dry weight, 12.2 mg L-1 culture and productivity of 0.9 mg L-1 day-1. The heterotrophy cultures reported a total EPA production of 2.7% of dry cell weight, 18 mg L-1 culture, a productivity of 1.3 mg L-1 day-1, which are promising values in the prospective of improving culture parameters for the biotechnological exploitation of dark cultivation. C. cryptica could be a potential candidate for the heterotrophic production of EPA, also considering its robustness, capacity to resist to bacterial contaminations and plasticity of lipid metabolism.

Are there real benefits to implanting cardiac devices in patients with end-stage dilated dystrophinopathic cardiomyopathy? Review of literature and personal results.

Cardiomyopathy associated with dystrophinopathies - Duchenne muscular Dystrophy (DMD), Becker muscular dystrophy (BMD), X-linked dilated cardiomyopathy (XL-CM) and cardiomyopathy of Duchenne/Becker (DMD/BMD carriers - is an almost constant manifestation of these neuromuscular disorders and contribute significantly to their morbidity and mortality. Dystrophinopathic cardiomyopathy is the result of the dystrophin protein deficiency at the myocardium level, parallel to that occurring at the skeletal muscle level. Typically, cardiomyopathy begins as a "presymptomatic" stage in the first decade of life and evolves in a stepwise manner toward an end-stage dilated cardiomyopathy. Nearly complete replacement of the myocardium by fibrous and fatty connective tissue results in an irreversible cardiac failure, characterized by a further reduction of ejection fraction (EF < 30%) and frequent episodes of acute heart failure (HF). The picture of a severe dilated cardiomyopathy with intractable heart failure is typical of dystrophinopathies. Despite an appropriate pharmacological treatment, this condition is irreversible because of the extensive loss of myocites. Heart transplantation is the only curative therapy for patients with end-stage heart failure, who remain symptomatic despite an optimal medical therapy. However there is a reluctance to perform heart transplantation (HT) in these patients due to the scarcity of donors and the concerns that the accompanying myopathy will limit the benefits obtained through this therapeutic option. Therefore the only possibility to ameliorate clinical symptoms, prevent fatal arrhythmias and cardiac death in dystrophinopathic patients could be the implantation of intracardiac device (ICD) or resynchronizing devices with defibrillator (CRT-D). This overview reports the personal series of patients affected by DMD and BMD and DMD carriers who received ICD or CRT-D system, describe the clinical outcomes so far published and discuss pro and cons in the use of such devices.

Heart transplantation in a patient with Myotonic Dystrophy type 1 and end-stage dilated cardiomyopathy: a short term follow-up.

Myotonic dystrophy type 1 (DM1) or Steinert's disease is the most common muscular dystrophy in adult life with an estimated prevalence of 1:8000. Cardiac involvement, including arrhythmias and conduction disorders, contributes significantly to the morbidity and mortality of the disease. Mild ventricular dysfunction has also been reported associated with conduction disorders, but severe ventricular systolic dysfunction is not a frequent feature and usually occurs late in the course of the disease. Heart transplantation is currently considered the ultimate gold standard surgical approach in the treatment of refractory heart failure in general population. To date, considering the shortage of donors that limit the achievement of a greater number of heart transplants and the reluctance of the cardiac surgeons to transplant patients with dystrophic cardiomyopathy, little is known about the number of patients with DM1 transplanted and their outcome. We report the case of a 44 year old patient with Steinert disease who showed an early onset ventricular dysfunction refractory to optimal medical and cardiac resincronization therapy, and underwent to successful heart transplantation. At our knowledge, this is the second heart transplantation performed in a patient affected by Steinert disease after the one reported by Conraads et al in 2002.

Right ventricular morphology and function in top-level athletes: a three-dimensional echocardiographic study.

BACKGROUND: Our objective was to explore the right ventricular (RV) dimensions and function and the effect of long-term intensive training in a large population of top level athletes using real-time three-dimensional (3D) echocardiography. METHODS: A total of 430 top-level athletes (220 endurance-trained athletes [ETAs] and 210 strength-trained athletes; 265 men [61.6%]; mean age 27.4 ± 10.1 years, range 18-40) and 250 healthy controls underwent a transthoracic echocardiographic examination. Three-dimensional RV measurements included serial short-axis reconstructions of the RV volumetric data sets, and the RV endocardial contour was traced with cross-reference to the long-axis images for identification of the tricuspid annulus. The end-diastolic and end-systolic RV volumes and ejection fraction were calculated off-line using the method of the summation of discs. RESULTS: The strength-trained athletes had a greater heart rate, body surface area, and systolic blood pressure at rest than the ETAs and controls. All RV diameters and 3D volumes and all transmitral and transtricuspid Doppler indexes were greater in the ETAs. Also, the left ventricular stroke volume, cardiac index, and pulmonary artery systolic pressure were greater in the ETAs, and all two-dimensional and 3D RV systolic indexes were comparable. On univariate analysis, the 3D RV end-diastolic volume was significantly associated with advanced age, male gender, duration of training, endurance training, increased left ventricular stroke volume, and pulmonary artery systolic pressure. On multivariate analysis, in the overall study population, the type and duration of training (P < .01), pulmonary artery systolic pressure (P < .01), and left ventricular stroke volume (P < .001) were the only independent predictors of RV end-diastolic volume. CONCLUSIONS: The results of the present study have delineated the upper limits of the RV dimensions in highly trained athletes as measured by real-time 3D echocardiography. The RV end-diastolic volume was significantly greater in the ETA than in the strength-trained athletes and controls.

Evaluation of retinal abnormalities in essential hypertension: qualitative fundoscopy versus central retinal artery resistance index as indicators of target organ damage.

PURPOSE: To compare qualitative fundoscopy with resistance index (RI) of the central retinal artery determined using color Doppler examination as indicators of target organ damage in a large population of patients with essential hypertension. METHOD: We compared qualitative fundoscopy and central retinal artery RI (CRARI) in 459 patients with grade I and II essential hypertension. Correlations with left ventricular mass, carotid structural changes, and diastolic function were investigated. The results were analyzed according to the degree of retinopathy (grade I versus grade II) and CRARI (<0.70 versus >or=0.70). All patients underwent carotid sonography, echocardiography, diastolic function, a sonographic examination of the eye with measurement of CRARI, and examination of the fundus oculi. RESULTS: There was no statistical difference in the parameters studied between patients with grade I and patients with grade II retinopathy on fundoscopy. Patients with CRARI >or=0.70 were older and had higher systolic and pulse pressure, more years of hypertension, increased left ventricular mass index, carotid intima media thickness, and diastolic parameters compared with patients with CRARI <0.70 (p < 0.001). A positive correlation was found between CRARI and age, pulse pressure, carotid intima media thickness, systolic blood pressure, and duration of hypertension, whereas a negative correlation was found between CRARI and diastolic parameters. Age, pulse pressure, carotid intima media thickness, and left ventricular mass index were independently related to CRARI. CONCLUSION: Our findings indicate that CRARI is more reliable than traditional fundoscopy in the evaluation of hypertension-induced organ damage and should be used to measure global cardiovascular risk for tailored therapy.