Many HCM patients, perhaps even the majority, are currently unable to identify the specific gene behind their HCM through genetic testing. Despite this obvious difference, family screening, risk stratification and treatment standards are no different for patients who carry a HCM gene and those who do not have identified gene(s).
A recent article published in Circulation suggests that there ARE differences which should result in different treatment for this subset of patients.
In particular, non-sarcomere positive patients:
- have a better prognosis, with lower rates of heart failure, sudden death, atrial fibrillation and stroke
- Have lower incidence of family members affected by the disease
- Are more likely to have additional medical conditions such as obesity, hypertension and diabetes
The article by Dr. Hugh Watkins, a British HCM and genetic expert, suggests that:
- the risk to first degree relatives of this type of HCM patient is less than 50% and therefore, there is less need for repeated screening of relatives
- Hypertension should be treated more aggressively in these patients.
Read more about non-genetic HCM here and more about screening these patients here on HCMBeat.
A recent discovery by British researchers sheds light on how a type of common genetic mutation – a so called “common variant” – influences the expression of hypertrophic cardiomyopathy caused by mutation(s) in the cardiac sarcomere.
How do Common Variants Impact Sarcomere Mutations?
This research, funded by the British Heart Foundation and spearheaded by Dr. Hugh Watkins of the University of Oxford, explains why some individuals with a particular sarcomere mutation develop a severe case of HCM, while their family members with the same mutation may develop only mild HCM symptoms or show no signs of the disease at all. It also may explain why people who lack sarcomere mutations develop the disease.
The researchers compared the DNA of 2,780 people with HCM and 47,486 people without HCM and found that common variants acting in concert with rare sarcomere mutations determine whether a person will develop HCM.
Common Variant HCM Not Hereditable
In addition, the researchers found that HCM attributable to common variants alone is unlikely to be passed on to future generations. This is good news for the children of HCM patients caused by common variants.
Watch your Blood Pressure
Lastly, this paper found that high diastolic blood pressure was associated with the development of HCM caused by common variants. Hence, keeping blood pressure under control is something that patients can do to minimize their risk of developing HCM in the future.