From the Guidelines
Acute myocarditis causing death in a 1-year-old does not necessarily mean future children will be affected, as most cases are caused by viral infections or immune responses rather than genetic factors. However, there are rare genetic forms of myocarditis that could potentially affect future children. If the child's myocarditis was caused by a genetic condition like familial dilated cardiomyopathy or certain metabolic disorders, there may be an increased risk for siblings or future children 1. Parents who have lost a child to myocarditis should consider genetic counseling and possibly genetic testing to determine if there was an underlying hereditary component. A thorough evaluation of the deceased child's medical records, including any genetic testing or autopsy results, would be important to assess risk. For families concerned about this possibility, preconception genetic counseling and prenatal cardiac screening during future pregnancies may be recommended 1.
Some key points to consider:
- Most cases of acute myocarditis in children are caused by viral infections or immune responses rather than genetic factors 1
- Rare genetic forms of myocarditis, such as familial dilated cardiomyopathy, can increase the risk for future children 1
- Genetic counseling and testing can help determine if there was an underlying hereditary component 1
- Preconception genetic counseling and prenatal cardiac screening may be recommended for families concerned about this possibility 1
- The risk of myocarditis in future children is difficult to assess without knowing the specific cause of the original case, but most cases of pediatric myocarditis are not hereditary 1.
It's essential to note that the risk of sudden cardiac death (SCD) in individuals with a family history of SCD is increased, with a relative risk of 1.89 for one parental history of sudden death and 9.44 for two parental histories of sudden death 1. However, this does not directly translate to an increased risk of myocarditis in future children. A thorough evaluation and genetic counseling are necessary to assess the risk and provide guidance for families.
From the Research
Acute Myocarditis and Future Children
- Acute myocarditis is an inflammatory disease of the heart that can present as sudden death in infants and children, with various etiologies including infectious agents, systemic diseases, and toxins 2.
- The risk of acute myocarditis in future children is not directly addressed in the provided studies, but it is known that genetic defects can contribute to the progression of myocarditis to dilated cardiomyopathy phenotype 3.
- A study found that 8% of patients with acute myocarditis had genetic variants associated with dilated cardiomyopathy (DCM) or arrhythmogenic cardiomyopathy (ACM), which may have implications for family screening and genetic counseling 4.
- Genetic testing may provide important information regarding prognosis and family assessment in cases of acute heart failure presumed to be myocarditis, as 87% of individuals who underwent genetic testing were found to have a genetic syndrome or pathogenic variant in a cardiac-related gene 5.
Genetic Considerations
- Genetic aetiologies should be considered in pediatric cases of acute heart failure presumed to be myocarditis, as genetic disorders may contribute to a significant portion of these cases 5.
- The annual incidence of pediatric cardiomyopathies is higher during the first two years of life, and adverse events such as severe heart failure, heart transplantation, or death usually appear early after the initial presentation 3.
- A genetic defect is considered responsible for the progression to dilated cardiomyopathy phenotype, and a dilated or arrhythmogenic cardiomyopathy phenotype might emerge with an episode of acute myocarditis in childhood or adolescence 3.
Clinical Implications
- Early cardiac support may be the only option to prevent fatal outcome in cases of acute myocarditis, and clinical awareness of myocarditis is crucial for timely diagnosis and treatment 2, 6.
- Genetic counseling and testing should be considered in patients with acute myocarditis to help reassure the majority while improving the management of those with an underlying genetic variant 4.