Why is Next-Generation Sequencing (NGS) important to cardiovascular medicine? NGS has been successful in diagnosing certain cardiovascular diseases, called Mendelian diseases, that are present because of a single variant in a single gene or monogenic diseases.
It’s important to diagnose these diseases early, not only in one patient but in the first generation family members. Why? Because these patients may not exhibit any symptoms until a catastrophic symptom appears such as Sudden Cardiac Death (SCD) or aortic dissection, the tearing of the aortic blood vessel wall.
According to an American Heart Association Journal article,
“The most common monogenic cardiovascular disorders are transmitted in families in an autosomal dominant fashion. In such autosomal dominant disorders, it is important to remember the overriding principle that any first-degree relative of an individual with an autosomal dominant multigenerational familial cardiovascular disorder has a 50% chance of also being affected by this genetic trait”.
To rest easy the minds of these possible recipients of this genetic anomaly, NGS can provide a diagnosis to these otherwise difficult to diagnose single-gene disorders. Once NGS has established a diagnosis of these Mendelian diseases, treatment and procedures can commence, lessening the chances of a catastrophic event like SCD. Let’s take a look at some examples of three heart disorders that can be caused by hereditary genetics:
Hypertrophic Cardiomyopathy (HCM)
HCM is a condition in which the left ventricle heart muscle becomes abnormally thick. As the thickness increases, the flexibility and elasticity of the muscle decrease. This makes the heart work harder to pump the blood.
Some people with the disorder have no symptoms and have no remarkable problems, but this does not mean they won’t suffer a catastrophic heart event anytime in their lives. For others, symptoms can start as shortness of breath and becoming weaker during physical effort. As the disease progresses, symptoms include chest pains, arrhythmia or irregular beating of the heart, dizziness, swelling of the legs, and chronic fatigue leading, eventually, to a heart attack.
Again, the challenge is to diagnose these patients before the onset of catastrophic heart symptoms.
Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC)
The genetic defects that present this disease causes fatty, fibrous tissue to replace heart muscles in the ventricles, or lower chambers of the heart. More commonly this happens in the right ventricle rather than the left.
Again, some people will exhibit no problems or symptoms, but that does not mean that they are immune to a Sudden Cardiac Death or heart failure. Others will show signs of palpitations, sudden, temporary loss of consciousness, heart failure, or SCD.
With modern medical technology, it has gotten easier to diagnose ARVC from other conditions. However, a diagnosis starts with symptoms. If a person hasn’t any symptoms, they may miss being diagnosed and treated for this condition before it’s too late. NGS can diagnose earlier rather than later.
Generally, Marfan Syndrome can create havoc on the connective tissue system involving multiple organs. This includes affecting the heart by causing ruptures and bleeding in the aortic vessel’s inner wall. It can also cause the heart valves to swell which can cause shortness of breath and irregular heartbeats.
Even though Marfan Syndrome has been studied for many decades, accurate diagnosis is still difficult to obtain. Let’s save one more life with Next-Generation Sequencing by contacting us for more information.