According to researchers at the University of Michigan, family members of HCM patients who have tested negative for genes associated with HCM and without a family history of HCM will usually be found to be free of HCM during routine family screening. And, in accordance a recent Australian study, relatives of these patients may be able to benefit from less rigorous screening protocols.
Patients with a known sarcomere mutation appear to have a different clinical profile, according to the researchers: they have more hypertrophy; they are younger when diagnosed; they have a higher risk for adverse events; and they are more likely to have a family history for the condition.
In contrast, when the initial diagnosis is made in a patient who is 50 or older with no known genetic mutations, a negative family history, and sigmoidal septal pattern hypertrophy, reduced family screenings may be appropriate and less burdensome. In addition, hypertension, large family size with no other affected family members, less severe hypertrophy, and lack of life-threatening complications related to HCM may provide additional comfort to families of newly diagnosed HCM patients.
The reduced protocol would consist of a single screening of adult family members, with the caveat that if and when any additional family additional member is found to have HCM, a more traditional screening protocol be instituted.
(Note that standard screening guidelines recommend screening of all first-degree family members of patients beginning with adolescence, repeated annually through the end of adolescent growth, and repeated every 3 – 5 years for life.)