Sarawak Heart Foundation Contributes to Fund for Genetic Testing for Inherited Cardiovascular Disease

The Foundation has contributed RM 50,000 to start up a fund for genetic testing for inherited cardiovascular disease at Sarawak Heart Centre.

An inherited cardiovascular disease is one that has been passed on through families. Many cardiac diseases can be inherited, including cardiomyopathy, high cholesterol, arrhythmias and congenital heart disease. They can affect people of any age. People with inherited cardiovascular can present with palpitations, fainting spells, shortness of breath, chest pain and sudden death. Some may have no symptoms at all. If one parent has a faulty gene, there is a 50% chance that a person could have it too. And if the person carries the faulty gene, there is a 50% chance that it can be passed down to his or her children.

Since January this year, the Department of Cardiology has started engaging genetic testing service from a US-based company called INVITAE (https://www.invitae.com/en). A single genetic test costs USD 250 (approximately RM 1000) per person. Including transportation fees ranging from RM250 to RM260 (depending on current fuel price), a person needs to pay up to RM1260 for the test. The company provides free testing for first-degree family members if the person is tested positive for a pathogenic mutation. Whenever there is a clinical suspicion of inherited cardiovascular disease, the treating cardiologist will counsel the patient about genetic testing. After obtaining the patient’s written consent, a date will be arranged for sample collection (saliva). The results will be available in approximately 3 weeks from the time of sample collection.

One patient who has heart failure for the past 2 years, has undertaken the test under Sarawak Heart Foundation’s funding and is diagnosed to have hereditary transthyretin cardiac amyloidosis. This heart disease is not common and requires special treatment. A few others are still waiting for their turn.

The fund will help patients from the low-income group who cannot afford the test. Besides benefitting the patients, the genetic test will enable early detection of disease among their close family members.

Inherited Cardiovascular Disease and Genetic Testing

Contrary to many people’s beliefs, inherited cardiovascular diseases are not uncommon. In our center, the commonest inherited cardiovascular disease seen is hypertrophic cardiomyopathy (HCM). HCM is a disease affecting the heart muscle, causing it to thicken abnormally. Patients with HCM can present with shortness of breath, chest pain, palpitations and fainting spells. However, many patients with HCM under our care, are healthy individuals who display no symptoms. They are usually referred to us because of abnormal heart findings from a health check.

In the past, when genetic testing is not available, family screening for inherited cardiovascular
disease is carried out in the form of performing a 12-lead electrocardiogram (ECG) and ultrasound of the heart on all first-degree family members. This creates anxiety and uncertainties among family members, especially the younger ones, who may be a carrier of the affected gene but have not shown any clinical manifestation. Genetic testing enables us to be more targeted in cascade screening of family members. Those family members who are tested negative are certainly free from the disease. On the other hand, those who are tested positive may or may not have the disease. This is because some individuals are only carriers of the mutated gene, and will not have any clinical manifestation of the disease in their entire life. But they can still pass on the gene to their children.

We often get a question from patients like “will a genetic test change the treatment of our heart disease?”. Unfortunately, there is currently no cure for most inherited cardiovascular diseases. The treatment provided is mainly for symptom alleviation and prevention of sudden cardiac death. But, there are studies examining treatment targeted at the mutated gene, and the findings showed promising results. In the future, these investigational treatments called gene therapy might offer a complete cure for inherited cardiovascular disease.

We understand that there are many social implications if a person is tested positive for an inherited cardiovascular disease. Those who are professional athletes will be advised to stop participating in competitive sports, hence affecting their career and income. Insurance companies may impose certain restrictions or limit on their coverage. And the fear of passing down the gene to their offspring may hinder one from having a child. That is why we provide counseling before genetic testing, and when the results are out, another session of counseling will be arranged to explain the test results and the next course of action.

We will try our best to help you and your family, so allow us to explain genetic testing to you when it is indicated. There may be no cure for the heart problem at present, but in the future, things might change.

By Dr Oon Yen Yee
Consultant cardiologist,
Department of Cardiology,
Sarawak Heart Centre