What if your doctor could remove the building blocks of heart disease?

Gene editing will fundamentally change the way we fight medical conditions

Genetic science has taken cardiologists a long way in solving the puzzle of heart disease. Getty

Most of us will remember what we were doing the day of a significant global event. The day two planes flew into the twin towers. The day the Berlin Wall came down. The day a tsunami hit the shores of Indonesia.

As a doctor, I remember one day doing my ward rounds in 2000 when then UK prime minister Tony Blair and then US president Bill Clinton announced that the full human genome was finally sequenced. While it was inspiring to hear that the “blueprint” of humans was now known, I still had sick patients on my list yet to be seen and discharged. For them, the relevance of the discovery could not have felt more remote.

Not every advance is momentous. Most ground-breaking changes cannot be pinpointed to a single press conference. They are instead the result of many smaller, incremental advances, as we cardiologists would be soon be reminded.

Around the time we first understood the human genome sequence, we discovered that humans have virtually the same number of coding genes (roughly 20,000) as a worm or fish.

What makes us different are the 3 billion remaining base pairs of the non-coding genome. In these, we find what are called gene regulatory elements. They are more easily visualised as “switches”, which control when and how much our genes are expressed.

The blueprint of the human genome can be thought of as a songbook. Different musical notes are sung by different cells, often in unison. And so, we have lung cells performing differently to heart or liver cells even though they all have the same blueprint. The circuitry involved is complicated and intricate.

Despite this complexity, now is a fantastic time to be working in genomic research. Technological advances reveal how different sections of the genome and its switches underpin cellular functions throughout the body. With technology, doctors can sequence our patients’ genomes at accessible costs, control their gene expression and even edit their blueprint. This allows us to target the root cause of diseases.

Indeed, such technology has already informed life-saving new therapies for cancer. When cardiologists watched Mr Blair and Mr Clinton’s 2000 announcement, it kindled hopes of new cures and therapies. Now, were are finally moving closer to such solutions for complex and multifactorial heart diseases.

The blueprint of the human genome can be thought of as a songbook

For example, mapping out the genes that cause high cholesterol has had a huge impact. We now think it may be possible to safely edit such genes in adult genomes, giving people a reduced risk or even lifelong protection against heart disease. In the meantime, suppressing gene expression related to heart disease using twice-yearly injections of gene targeting medicines will be far more effective than the daily, oral doses of statins patients currently take.

A new generation of medicines is emerging as a result of our ever-deepening understanding of the genomic map. Targeting genomic switches in order to re-programme gene expression would reverse the course of disease rather than simply slow its progression. The latter is what nearly all medicines today do.

The future of cardiology is glowing with excitement as we pursue a solution to the scourge of heart disease, which blights the lives of many – particularly those at elevated risk, such as the elderly and sufferers of metabolic diseases and diabetes. These risk factors are at an all-time global high. For cardiology, the next generation of ground-breaking medicines is firmly on its way and could not be welcomed sooner.

Professor Roger Foo is Sheikh Zayed bin Sultan Al Nahyan Professor in Medicine at the National University of Singapore