Novel risk predictor of arrhythmias for patients with potassium channel-related congenital long QT syndrome.

Background: Congenital long QT syndrome (LQTS) is characterized by delayed ventricular repolarization, predisposing to potentially lethal ventricular arrhythmias. The variability in disease severity among patients remains largely unexplored, underscoring the limitations of current risk stratification methods.

Objective: We aimed to evaluate the potential utility of electrocardiographic markers from the exercise stress test (EST) in identifying patients with high-risk LQTS.

Human Genetics of Cardiac Arrhythmias.

Inherited forms of cardiac arrhythmias mostly are rare diseases (prevalence <1:2000) and considered to be either "primary electrical heart disorders" due to the absence of structural heart abnormalities or "cardiac ion channel disorders" due to the myocellular structures involved. Precise knowledge of the electrocardiographic features of these diseases and their genetic classification will enable early disease recognition and prevention of cardiac events including sudden cardiac death.The genetic background of these diseases is complex and heterogeneous.

KCNQ1 is an essential mediator of the sex-dependent perception of moderate cold temperatures.

Low temperatures and cooling agents like menthol induce cold sensation by activating the peripheral cold receptors TRPM8 and TRPA1, cation channels belonging to the TRP channel family, while the reduction of potassium currents provides an additional and/or synergistic mechanism of cold sensation. Despite extensive studies over the past decades to identify the molecular receptors that mediate thermosensation, cold sensation is still not fully understood and many cold-sensitive peripheral neurons do not express the well-established cold sensor TRPM8. We found that the voltage-gated potassium channel KCNQ1 (Kv7.

Generation of a patient-specific hiPS cell line with heterozygous GNB2 mutation (UKMi003-A) causative for human sinus node dysfunction and a corresponding CRISPR/Cas9-corrected isogenic control (UKMi004-A).

The heterozygous mutation c.155G > T in GNB2 clinically leads to sinus bradycardia and sinus node dysfunction. Here, patient-specific skin fibroblasts of the mutation carrier were used for Sendai virus reprogramming into human induced-pluripotent stem cells (hiPSC).

[Cardiogenetics in Germany- a view and review].

The development of the cardiogenetics field in Germany has been increasing since the mid-1990s with many national contributions, some of them were really important and groundbreaking. The starting point was and still is the patient and his family, e.g.

Case Report: Hypertrophic cardiomyopathy with recurrent episodes of ventricular fibrillation and concurrent sinus arrest.

Background: Hypertrophic cardiomyopathy (HCM) is a serious hereditary cardiomyopathy. It is characterized morphologically by an increased left ventricular wall thickness and mass and functionally by enhanced global chamber function and myocellular contractility, diastolic dysfunction, and myocardial fibrosis development. Typically, patients with HCM experience atrial fibrillation (AF), syncope, and ventricular fibrillation (VF), causing severe symptoms and cardiac arrest.

The W101C Mutation Induces Slower Pacing by Constitutively Active GIRK Channels in hiPSC-Derived Cardiomyocytes.

Mutations in the gene, encoding one of the major subunits of cardiac G-protein-gated inwardly rectifying K (GIRK) channels, have been recently linked to inherited forms of sinus node dysfunction. Here, the pathogenic mechanism of the W101C mutation underlying sinus bradycardia in a patient-derived cellular disease model of sinus node dysfunction (SND) was investigated. A human-induced pluripotent stem cell (hiPSCs) line of a mutation carrier was generated, and CRISPR/Cas9-based gene targeting was used to correct the familial mutation as a control line.

Patient-derived stem cell line UKMi005-A (hiPSC) harboring a non-synonymous heterozygous KCNJ5 gene variant.

A published heterozygous gain-of-function variant in the KCNJ5 gene (p.Trp101Cys) encoding the G-protein-activated inward-rectifier potassium channel 4 subunit of the I channel is associated with human sinus node dysfunction (SND). Differentiated hiPSC-cardiomyocytes may serve as an in-vitro model to study SND and to develop pharmacological rescue strategies.

Cardiomyopathy related desmocollin-2 prodomain variants affect the intracellular cadherin transport and processing.

Background: Arrhythmogenic cardiomyopathy can be caused by genetic variants in desmosomal cadherins. Since cardiac desmosomal cadherins are crucial for cell-cell-adhesion, their correct localization at the plasma membrane is essential.

Methods: Nine desmocollin-2 variants at five positions from various public genetic databases (p.

Whole Exome Sequencing Identifies a Heterozygous Variant in the Cav1.3 Gene Associated with Familial Sinus Node Dysfunction and Focal Idiopathic Epilepsy.

Cav1.3 voltage-gated L-type calcium channels (LTCCs) are involved in cardiac pacemaking, hearing and hormone secretion, but are also expressed postsynaptically in neurons. So far, homozygous loss of function mutations in encoding the Cav1.

mTOR-Activating Mutations in Are Causative for Kidney Tubulopathy and Cardiomyopathy.

Background: Over the last decade, advances in genetic techniques have resulted in the identification of rare hereditary disorders of renal magnesium and salt handling. Nevertheless, approximately 20% of all patients with tubulopathy lack a genetic diagnosis.

Methods: We performed whole-exome and -genome sequencing of a patient cohort with a novel, inherited, salt-losing tubulopathy; hypomagnesemia; and dilated cardiomyopathy.