Hypertrophic cardiomyopathy : An update on one of the most commonly inherited heart conditions.

The human heart functions like a pump, pumping oxygen around the body to keep you alive.

It's a fist-sized muscle in the center of the chest that's slightly angled to the left.

Your heart beats 100,000 times a day. The circulatory system actively pumps approximately five litres (eight pints) of blood across the body across a network of blood vessels.This blood carries away excess carbon dioxide and waste products while delivering oxygen and nutrients to all areas of the body.

Unfortunately, with such a complex and vital organ, complications are likely to arise.

HCM (hypertrophic cardiomyopathy) is a hereditary heart muscle condition in which the muscle wall of the heart thickens. It is a genetic disorder that is passed down through families and is caused by a modification or mutation in one or more genes. Any child of someone who has HCM has a 50% chance of inheriting the disease.

The disorder affects around one in every 500 people in the UK, but most people with it have few, if any, symptoms.

Symptoms that are common include:

Breathing problems

- Pain in the chest

- Palpitations

- Fainting and light-headedness

While there is no remedy for HCM at this time, there are medications that can help manage the symptoms and avoid complications. For example:

Medicines – to help manage blood pressure and irregular heart rhythms.

A pacemaker - a device that regulates the heart rate.

An ICD - If you're at risk of developing a life-threatening irregular heart rhythm.

According to research funded by the British Heart Foundation (BHF) and published in Nature Genetics, new genetic flaws discovered in people with a heart disorder that is often inherited in families could change the diagnosis and treatment of the hidden disease.

Researchers have discovered a new form of genetic alteration in the DNA of people with hypertrophic cardiomyopathy.

This groundbreaking observation, which may be the most significant breakthrough in our understanding of the disease's genetic basis in 25 years, could help doctors better predict which members of a family should be screened for the disease and which can be ruled out of further testing or treatment.

Scientists have known for over 25 years that HCM is affected by 'rare' genetic flaws in the circuitry that helps the heart muscle contract and pump blood throughout the body. Researchers and cardiologists have never been able to understand why the disorder varies so much among family members who share the same unusual mutation, and why certain people who do not have these mutations develop HCM.

BHF Professor Hugh Watkins and his team at the University of Oxford's Radcliffe Department of Medicine have discovered that the inheritance of a certain type of genetic error, known as 'common variants,' that is not involved in the contractile machinery, is the missing piece to the puzzle.

The researchers discovered that the number of these common variants, in combination with unusual mutations, decide whether an individual is immune or more vulnerable to HCM by comparing the DNA of 2,780 people with HCM and 47,486 people without HCM. Another significant implication is that people who develop HCM as a result of common variants are unlikely to pass the disease on to their offspring.

Hugh Watkins, Radcliffe Professor of Medicine at the University of Oxford and Director of the BHF Centre of Research Excellence, said:

"It's past time for us to reconsider how we detect and handle this hidden heart disease."

"We now have a new genetic method that we hope will help us better predict the members of infected families will develop a severe type of the disease, allowing us to recognise those that need immediate treatment." Many families will be relieved because it will allow them to recognise those who are unlikely to pass on defective genes to their offspring. This will cut down on the number of needless genetic tests and follow-ups."

Professor Sir Nilesh Samani, the BHF's Medical Director and a cardiologist, stated:

"This study contributes significantly to our understanding of the genetics of hypertrophic cardiomyopathy." It will change the way we screen people who have relatives who are affected by this invisible murderer.

"Thousands of families around the UK are affected by HCM, which is one of the most common hereditary cardiac disorders." Many families will receive long-awaited results as a result of these findings, and many people will no longer be unable to undergo routine health examinations or think over whether they have inherited the disorder."

The study has a wide-ranging influence. It was also discovered that reducing blood pressure in people with HCM caused by these "common" genetic flaws could help prevent the disease from progressing.

With this groundbreaking research, the future for those with HCM looks more promising than ever.