The patients certainly needed a breakthrough. Early on, the only way cardiologists could diagnose cardiomyopathy was through a surgical procedure, known as cardiac catheterization: a doctor inserts a thin plastic tube into a blood vessel in a patient’s groin or arm and guides the tube toward the heart.

Because of the risks of any such invasive procedure, very few patients underwent it, unless they showed clear symptoms of disease, which often they did not.

Then, in the 1980s, about the same time the Seidmans were detecting genes linked to cardiomyopathy, cardiologists came up with a non-invasive procedure called echocardiography, which images the heart via sound waves.

Today, echocardiography has evolved into robust technology, able to display a patient’s beating heart in two dimensions. But still the technique can only spot the cardiomyopathy after a patient’s heart has already thickened, after the damage is already done.

What doctors and their patients need is a test, a diagnostic that can pinpoint the telltale mutations and help prescribe the proper treatment.