Should molecular screening be performed in family members of genotyped LQTS patients to identify silent gene carriers?
Clinical evaluation alone is insufficient to exclude LQTS in family members of affected patients; molecular screening is recommended to identify silent gene carriers.
This study demonstrates that in some families, LQTS may appear with a very low penetrance, a finding with multiple clinical implications. The family members considered to be normal and found to be silent gene carriers are unexpectedly at risk of generating affected offspring and also of developing torsade de pointes if exposed to either cardiac or noncardiac drugs that block potassium channels. It is no longer acceptable to exclude LQTS among family members of definitely affected patients on purely clinical grounds. Conversely, it now appears appropriate to perform molecular screening in all family members of genotyped patients.
Priori et al. (Tue,) studied this question.
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