SNP Shot: Genomic Insights

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a heart condition marked by an irregular heartbeat, or arrhythmia. During physical exertion or emotional stress, the heart rate increases, potentially initiating a dangerously rapid heartbeat known as ventricular tachycardia. This rapid heartbeat can lead to symptoms like light-headedness, dizziness, and fainting (syncope), often appearing in childhood for those with CPVT.

If CPVT goes undiagnosed and untreated, ventricular tachycardia episodes can lead to cardiac arrest, where the heart stops beating, potentially resulting in sudden death. CPVT is believed to be a notable contributor to unexplained sudden deaths in children and young adults with no previously known heart issues.

Inheritance:

When CPVT arises from mutations in the RYR2 gene, it follows an autosomal dominant inheritance pattern. This means that having just one copy of the altered gene in each cell is enough to cause the disorder. Approximately half of affected individuals inherit the RYR2 gene mutation from a parent who also has the condition. The other half of cases are due to new (de novo) mutations in the RYR2 gene. These new mutations occur either during the creation of egg or sperm cells in the parent, or during early development of the embryo. These individuals have no family history of the disorder. When CPVT is caused by mutations in the CASQ2 gene, it almost always follows an autosomal recessive inheritance pattern. This pattern requires that both copies of the gene in each cell have mutations to cause the condition. The parents of someone with an autosomal recessive condition each carry one mutated copy of the gene, but usually don't show any signs or symptoms of CPVT. In rare instances, CASQ2-related CPVT may be inherited in an autosomal dominant manner. When mutations in other genes cause CPVT, it can be inherited through either an autosomal dominant or autosomal recessive pattern.