CACNA1C Awareness Day Date in the current year: October 1, 2025

The CACNA1C gene provides instructions for making a protein that forms part of a calcium channel in the membranes of certain cells, particularly in the heart and brain. These channels open and close to allow calcium ions to move into cells. This process is crucial because it helps control electrical signals in nerve cells, coordinate heart muscle contraction, and influence gene activity.

Mutations in the CACNA1C gene cause neurological and heart disorders, such as Timothy syndrome and Brugada syndrome. Timothy syndrome is characterized by an abnormally long QT interval on an electrocardiogram (long QT syndrome), cardiac arrhythmia, structural heart defects, autism spectrum disorder, facial deformities, and dental problems.

There are two types of Timothy syndrome: type 1 (classical) and type 2. Patients with the classical type usually have syndactyly (webbed fingers or toes), while patients with type 2 Timothy syndrome do not have syndactyly but often have musculoskeletal issues, such as hyperflexible joints and hip dysplasia, as well as more pronounced facial deformities.

There is no cure for Timothy syndrome. Treatment options include surgery to correct syndactyly and heart abnormalities, as well as the use of beta-blockers and pacemaker implantation to combat arrhythmia. More than half of children with Timothy syndrome die by an average age of 2.5 years, and survivors usually have severe developmental delays. With proper care, some patients are able to live into their mid- or late twenties.

Brugada syndrome is characterized by an increased risk of abnormal heart rhythms. These rhythms present as a short QT interval on an electrocardiogram, making Brugada syndrome a subtype of short QT syndrome. The syndrome typically does not present with any obvious symptoms, but arrhythmia episodes may cause fainting or sudden cardiac death. These episodes often occur after a heavy meal or excessive alcohol consumption. They can also be triggered by fever and sodium-channel-blocking medications.

Like Timothy syndrome, Brugada syndrome is incurable. Treatment focuses on reducing the risk of sudden cardiac death and may include lifestyle changes to avoid possible arrhythmia triggers, such as avoiding alcohol consumption and certain medications and promptly treating fevers. Treatment may also include implanting an implantable cardioverter-defibrillator, taking antiarrhythmic medications, or undergoing catheter ablation.

CACNA1C Awareness Day is spearheaded by the Timothy Syndrome Alliance, a UK-based charity whose mission is to improve the diagnosis, treatment, and care of individuals with Timothy syndrome and other CACNA1C-related disorders. Observed on October 1, the day aims to educate the public about disorders caused by mutations in the CACNA1C gene, support patients and their families, and encourage research to improve early diagnosis and treatment strategies.