Hereditary heart disease risk assessment /
genetic testing service
Categories of Testing
Atherosclerosis gene detection
ATS Panel
Purpose
Atherosclerosis (ATS) is a disease in which atherosclerotic plaque deposits on the blood vessel wall and causes arterial stenosis. ATS is caused by the damage of vascular endothelium, the aggregation of white blood cells and platelets, the accumulation of cholesterol, fat, thrombus, various connective tissues, calcium ions, and the proliferation of vascular smooth muscles, which together form atheroma plaques. The blood vessels are hardened, narrowed, or even blocked.
ATS can easily lead to a variety of cardiovascular diseases (CVD) such as ischemic heart disease, cerebrovascular disease, carotid artery stenosis, aortic aneurysm and thickening of aortic dissection. Male, elder people, and those with a family history of heart disease are at higher risk. There may be no symptoms or no obvious symptoms in the early stages of atherosclerosis. Common symptoms of ATS are chest tightness, chest pain, dyspnea, pasty faced, cold sweating, vertigo, nausea, and general weakness. Many studies have shown that atherosclerosis is caused by the interaction between genes and the environment.
Leopard Gene applies the next-generation sequencing (NGS) gene detection platform to design the “Atherosclerosis (ATS) Gene panel”, which detects gene mutations related to atherosclerosis, and evaluates the correlation between atherosclerosis and gene mutations in individual cases. It can be a useful reference information for follow-up medication and treatment.
Hypertrophic Cardiomyopathy Gene Detection
HCM Panel
Purpose
Hypertrophic Cardiomyopathy (Hypertrophic Cardiomyopathy, HCM) is a chromosomal dominant multifactorial heart disease caused by abnormal myocardial thickening. In most patients myocardial thickening begins gradually during adolescence, and only a small portion of patients develop the disease in infancy. HCM usually occurs between the ages of 20 and 40. Epidemiological studies have shown that the prevalence of HCM in adults is about two per thousand, and it is the most common cardiomyopathy. Among the causes of sudden death in young athletes, hypertrophic cardiomyopathy accounts for the most, about 35%.
The most common location of HCM is the local hypertrophy of the ventricular septum. Myocardial hypertrophy will cause the volume decrease of the ventricular chambers and reduce the blood output of the heart. In addition, due to myocardial hypertrophy and lack of elasticity, it will eventually lead to difficulty in ventricular diastole, which is prone to diastolic heart failure. The vast majority of patients are actually asymptomatic, and the average life expectancy is no different from the normal populations. Only small portions of patients exhibit symptoms. Common symptoms include: chest tightness, wheezing (especially during exercise), fatigue, weakness, palpitations, arrhythmia, heart failure, fainting and sudden cardiac death. Clinical care of patients mainly include: tracing family history, relieving symptoms, assessing the risk of sudden cardiac death and surgical treatment.
HCM is mostly a hereditary disease. Screening high-risk groups through genetic testing can support early detection of hypertrophic cardiomyopathy and treatment to avoid sudden death.
Leopard Gene applies next-generation sequencing (NGS) to sequence all exon of 26 HCM-related genes to detect whether patients have high risk genetic mutations, assist physicians in HCM diagnosis, and facilitate treatment, medication and prognosis evaluation.
Dilated Cardiomyopathy Gene Detection
DCM Panel
Purpose
Dilated Cardiomyopathy is a primary cardiomyopathy of chromosomal dominant inheritance. About 20-35% of patients have a family history. The incidence frequency of male is higher than that of female, and the age of onset is mainly concentrated in the ages of 20 to 60. Dilated cardiomyopathy is the most common cardiomyopathy in children.
The most common reason for heart transplantation in children comes from DCM. The five-year survival rate of DCM in children is about 60%.
DCM is pathologically characterized by enlarged heart, reduced left ventricular function and weakened contractility. Symptoms include congestive heart failure, arterial embolism, and sudden death. More than 80% of sick children also have gastrointestinal symptoms such as growth retardation, weakness, dyspnea, or vomiting. In severe cases, heart failure or even shock may occur. Heart transplantation is the only golden remedy.
International Board of Heart Rhythm Examiners recommends genetic testing for DCM patients. Leopard Gene applies next-generation sequencing to sequence the whole exon of DCM-related genes to detect whether patients have high risk genetic mutations and assist physicians in DCM diagnosis, and facilitate treatment, medication and prognosis evaluation.
Degenerative Mitral Valve Disease Genetic Detection
DMVD Panel
Purpose
Degenerative Mitral Valve Disease (DMVD) is a kind of common disease and approximately 2-3% of the populations in the world are suffering from it. The Chinese population has 2.2% prevalence rate and a high mortality rate.
The normal switch of the mitral valve plays a very important role in the systolic and diastolic cycle of the heart. The problem of DMVD is mostly caused by the degeneration of mitral valve, which leads to loosening, lengthening, and thickening of the cardiac valve. The phenomenon induces the incomplete atresia to form reflux and long-term heart failure combined with dyspnea and pulmonary edema.
Common clinical symptoms of DMVD include chest tightness, chest pain, palpitations, arrhythmia (especially atrial fibrillation), dyspnea, dizziness, fatigue and so on.
Leopard Gene applies next-generation sequencing (NGS) to sequence 35 genes related to DMVD and the associated mutation alleles to detect whether patients have high risk genetic mutations, and assist physicians in diagnosis, treatment and prognosis evaluation of DMVD patient.
Arrhythmogenic Right Ventricular Cardiomyopathy Gene Detection
ARVC Panel
Purpose
Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC) is an autosomal dominant hereditary disease. As long as one of the parents has a disease-causing gene mutation, the risk of the next generation carrying the mutant gene is as high as 50%. ARVC is common in young and middle-aged males and is three times more common than in females. According to studies, 20% of sudden deaths among young people are caused by ARVC.
The pathological characterization of ARVC is the gradual replacement of myocardial cells by fat and fibrous tissue, extending from the epicardium to the endocardium, resulting in thinning of the right ventricular wall, defects and necrosis of the heart muscle, and arrhythmia. The clinical symptoms are palpitations, chest pain, and dizziness.
The International Board of Heart Rhythm Examiners recommends that genetic testing be performed on patients to assist physicians in diagnosing ARVC, which is helpful for treatment, medication and prognosis evaluation.
TAAD Panel for Genetic Testing of Thoracic Aortic Aneurysm Dissection Syndrome
Purpose
The aorta are large blood vessels that carries blood away from the heart and distributes the blood throughout the whole body. The aortic wall can be divided into three layers: the innermost layer is the vascular endothelium that can prevent blood clotting; the middle layer is the muscle layer to maintain the integrity of the vascular structure; the outermost layer is the solid fibrous layer.
If the aorta is locally enlarged to more than one and a half times of the original diameter, it is called an aortic aneurysm, which means that the aortic wall is abnormally enlarged. Aortic aneurysms can occur everywhere in the aorta.
Thoracic Aortic Aneurysm and Dissection (TAAD) is caused by the tearing of the aortic intima, causing the aortic wall (including the ascending aorta) to separate to form a dissection, which causes the thoracic aorta near the rupture site to expand to form an aortic aneurysm. A thoracic aortic aneurysm may rupture at any time and cause massive bleeding and rapid death by insufficient coronary blood supply. When a thoracic aortic aneurysm compresses nearby nerves, it can cause chest pain and back pain. Common causes of thoracic aortic aneurysm dissection include: degenerative changes of the aortic muscle membrane, hypertension, arteriosclerosis, iatrogenic injury, inflammation, hereditary diseases (such as Marfan syndrome), and syphilis.
In acute aortic syndrome, the mortality caused by aortic rupture is as high as 50%, which is caught off guard. For TAAD detected early before rupture or dissection, the risk of operative mortality is less than 15%. Early diagnosis is helpful for improve the survival rate of patients.
Leopard Gene applies next-generation sequencing (NGS) to sequence whole exon of 34 TAAD-related genes to detect whether patients have highly genetic mutations, and assist physicians in diagnosis, treatment and prognosis evaluation of TAAD patients.
Frequently asked questions
Recently, there have been cases of sudden death of young men aged 30 to 40 years old, which have left people shocked. In fact, sudden deaths are still dominated by the elderly at present, and with the increase of age, the incidence rate gradually increases. Although the rate of sudden death among young adults is not high, because of people’s proactive thinking, the younger the sudden death is, the more likely it is to alarm people. In addition, media reports have misled the general population to believe that “sudden death occurs frequently among young adults.”
According to the definition of “sudden death” by the United Nations World Health Organization (WHO), it means that there are no signs or symptoms, and the entire process takes less than one hour from the onset of symptoms to death. According to relevant domestic or international literature reports, the main root cause for sudden death is psychogenic disease, accounting for an average of 50% to 80% or more, caused by myocardial infarction, severe angina, cardiomyopathy, and arrhythmia.
Generally speaking, there are two peak periods of sudden death in an individual’s lifetime: birth to 6 months, and 45 to 75 years of age. The incidence of sudden death in the latter is 100 times more than that of adolescence to 30 years of age. Sudden deaths between the ages of 45 and 75 are mostly caused by acquired heart diseases, such as arrhythmia caused by angina or valve problems, which slowly produce cardiomyopathy. In addition, some patients have genes which cause fatal arrhythmia or cardiomyopathy, but they have not been manifested when they were young, and the disease slowly emerges after the age of 45.
If someone in the family has died suddenly, it is recommended to do genetic testing for the risk assessment of hereditary heart disease. Early genetic testing helps to detect heart abnormalities before the onset of illness. Those with inherited heart disease genes can avoid heart-related problems by taking preventive actions such as regular health check, practice good habits, and active health management.