Severe heart defect likely caused by genet...( CINCINNATI - Hypoplastic Left Heart ...),Health

CINCINNATI - Hypoplastic Left Heart Syndrome (HLHS), a severe cardiovascular malformation that is difficult to treat and often lethal, is caused primarily by genetic factors, according to a new study by researchers at Cincinnati Childrens Hospital Medical Center. The study to be published in the Oct. 16 edition of the Journal of the American College of Cardiology is the first to show the high heritability and likely genetic underpinnings of HLHS and recommend a direction for future research into its cause, development and possible therapeutic strategies.

Our study demonstrates that HLHS has high heritability, suggesting it is caused almost entirely by genetic effects instead of environmental factors, and that families with a child with HLHS carry a significant recurrence risk of HLHS or related heart defects. This should be considered by physicians when counseling parents to ensure they are aware of potential risks, said Robert B. Hinton, Jr., M.D., a physician and researcher at Cincinnati Childrens and the studys lead author.

HLHS is rare, occurring in about two of every 10,000 children born, Dr. Hinton said. Of those children born with HLHS approximately 20 percent die during the first months of life, he added. Children with HLHS suffer from restricted blood and oxygen flow because their hearts are abnormally shaped with an underdeveloped left side. This can include an undersized and/or malformed left ventricle (the hearts primary pumping chamber), aorta, aortic valve or mitral valve. Despite significant advances in diagnosis and therapy, the condition remains challenging to treat and the specific causes remain unknown, Dr. Hinton said. Babies can survive HLHS by undergoing a series of three complex operations after birth or receiving a heart transplant.

The study at Cincinnati Childrens included 38 family-based test groups with a history of HLHS. Researchers found that 55 percent of those families had one or more blood relati
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