Should Children from HCM Families be Screened Earlier?

A recent study by doctors at Toronto’s Hospital for Sick Children suggests that current screening guidelines for children from HCM families are inadequate and should instead recommend earlier screening exams. In the U.S., screening begins at age 12 pursuant to American College of Cardiology (ACC)/American Heart Association (AHA) guidelines.  In Europe, screening begins at age 10 pursuant to the European Society of Cardiology (ESC) guidelines.

In particular, the doctors found that out of 524 children who underwent
family screening prior to age 18, 9.9% showed evidence of HCM at first screening and only 1.1% of these children were symptomatic. An additional 28 (5.4%) children developed HCM over 3 years of follow-up, while 41% of major cardiovascular events [death, sudden cardiac death, or need for major interventions such as myectomy, ICD implantation, or heart transplant] occurred in children before the age of 10 year. Therefore, the doctors suggest that certain children appear to be at elevated risk and should be followed from earlier ages.

In particular, the study showed that children at greatest risk are:

  • male
  • have a pathogenic genetic mutations in MYH7 or MYBCP3
  • Have a family history of sudden cardiac death

A companion editorial by Dr. Christopher Semsarian of the University of Sydney in Australia and Dr. Carolyn Ho of the Brigham and Women’s Hospital in Boston points out that even under current guidelines, while screening is optional before age 12 (2011 ACC/AHA Guidelines) or age 10 (2014 ESC Guidelines), screening should still be considered if there is a particularly malignant family history, the child is an athlete or if there are symptoms or other indications of disease.

Semsarian and Ho note that even though screening tests (echocardiograms and EKGs) and non-invasive, there can be both monetary and emotional costs to the family resulting from screening. Hence, they recommend individualization in screening as opposed to a blanket rule; especially given that information relating to genetic status, gender and family history are easily available.  Each family situation should be assessed individually, taking into consideration their own set of unique risk factors and their tolerance for risk.

Editor’s Note:  HCMBeat recently highlighted this study from the U.K. which similarly concluded that the age of screening children in HCM families should be lowered.

 

 

 

Are Your Genetic Test Results Valid?

A recent study by several HCM genetics researchers around the globe, led by Australia’s Dr. Jodie Inglesfound that 2/3 of genetic mutations previously reported to patients as HCM causative may actually NOT trigger HCM.

Continue reading “Are Your Genetic Test Results Valid?”

HCM Researchers Put their Heads Together to Improve Lives of HCM Patients

A recent paper published in the journal Circulation looked at the clinical course of approximately 4,600 HCM patients over the course of more than 24,000 clinical years, which the paper describes as the largest comprehensive cohort of HCM patients ever studied.

This study examined patients from eight high volume HCM centers which aggregated their institutional data into a database known as the Sarcomere Human Cardiomyopathy Registry (or the acronym the “SHaRe” for short). The results of the study showed that, in general, HCM patients are at substantially elevated risk for atrial fibrillation and heart failure, and have significantly higher mortality rates than that of the general U.S. population.

Continue reading “HCM Researchers Put their Heads Together to Improve Lives of HCM Patients”

Are HCM Kids With MYH7 Gene at Increased Risk?

A recent Canadian study found that children with HCM who carry a single mutation in the MYH7 gene or who have multiple HCM-causative genetic mutations are at increased risk of major adverse cardiac events when compared to children who carry a single mutation in another gene.

Of the 98 gene positive children in this study, those with a MYH7 mutation or those with multiple mutations were more likely to need a myectomy or an ICD or to experience a sudden cardiac arrest or a heart transplant when compared to children with other HCM causative mutations.

The article also suggests that current screening protocols which recommend clinical and genetic screening for HCM beginning at age 12 may be insufficient.

Unwitting Geneticist Discovers Her Own Cardiomyopathy Gene: Heidi Rehm’s Story

Dr. Heidi Rehm is a human geneticist and clinical laboratory director at Harvard Medical School who has spent much of her career studying the genetics of cardiomyopathy.

Imagine her surprise when she found out that she, her mother and her daughter all have a mutation in the MYH7 gene which has been associated with dilated cardiomyopathy!

The unexpected revelation came as an indirect result of a visit to her daughter’s orthodontist.  When one of her daughter’s teeth was delayed coming in, the orthodontist suggested that there might be a genetic cause for the late tooth.  This provided the idea behind her high school daughter’s summer biology research project: 2 weeks in her mom’s lab sequencing her exome, looking for a genetic cause for her delayed tooth.

Though the mouth genetics turned out to be normal and the tooth eventually arrived, an totally unexpected incidental finding turned up instead:  a variation in the MYH7 gene which has been associated with dilated cardiomyopathy.

Continue reading “Unwitting Geneticist Discovers Her Own Cardiomyopathy Gene: Heidi Rehm’s Story”

HCM May Develop Later in Life

A recent study followed 14 patients carrying one of two known genes associated with HCM (MYBPC3 and MYH7) over a 10+ year period .  At the time  of gene identification, none of the patients shown clinical evidence of hypertrophy.  Over the time span of the study, 3 patients, who were then adults, had developed signs of HCM.  Hence, the study suggests that periodic screenings are necessary for gene positive individuals throughout adulthood.

According to Cardiomyopathy U.K., the researchers undertook this project due to the lack of information and guidelines available to patients who are gene positive but have no outward signs of the disease.