RyR2mutationer

RyR2 mutations are alterations in the RYR2 gene, which provides instructions for making the ryanodine receptor 2. This receptor is a protein found primarily in the membrane of the sarcoplasmic reticulum, a specialized organelle within heart muscle cells that stores and releases calcium. The controlled release of calcium from the sarcoplasmic reticulum is essential for initiating and regulating the contraction of the heart muscle.

Mutations in the RYR2 gene can lead to a condition known as catecholaminergic polymorphic ventricular tachycardia (CPVT). CPVT is a serious inherited heart rhythm disorder. In individuals with RYR2 mutations, the ryanodine receptor 2 can become unstable, leading to abnormal and excessive calcium release from the sarcoplasmic reticulum, particularly in response to stress or physical activity. This chaotic calcium signaling disrupts the normal electrical activity of the heart, causing dangerous ventricular arrhythmias.

These arrhythmias can manifest as rapid, irregular heartbeats originating from the ventricles, the lower chambers of the heart. Symptoms of CPVT often include fainting (syncope), palpitations, and in severe cases, sudden cardiac arrest. The severity of CPVT can vary depending on the specific RYR2 mutation and other genetic and environmental factors. Diagnosis typically involves electrocardiogram (ECG) monitoring, often with exercise or drug challenge, and genetic testing to confirm the presence of an RYR2 mutation. Treatment strategies aim to prevent arrhythmias and may include beta-blockers, which help to reduce the heart's response to adrenaline, and sometimes more invasive procedures.