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The focus of Dr. Grossfeld’s Laboratory is on defining the genetic basis of congenital heart defects, the most common human birth defect. 

Dr. Grossfeld’s research has focused on a rare genetic syndrome, Jacobsen syndrome (JS), that is caused by the loss of the end of the long arm of human chromosome 11.  Dr. Grossfeld has determined that most of the common and severe congenital heart defects that occur in the general population occur in JS.  Dr. Grossfeld’s laboratory has identified the gene in 11q, ETS-1, that causes congenital heart defects in JS.  Using a combination of state-of-the art technologies including genetically engineered animal models and human induced pluripotent stem cells, Dr. Grossfeld’s laboratory is studying the function of the ETS-1 gene in normal heart development, and how loss of function causes congenital defects.  They have identified two specific populations of cells that are critical for normal heart development:  the cardiac neural crest and the endocardium.  Combining human genetics with genetically engineered animal model systems including mice, fruit flies, zebrafish, and frogs, Dr. Grossfeld and his collaborators have embarked on a multi-displinary approach to gain novel insights into some of the most complex congenital heart defects including hypoplastic left heart syndrome (HLHS).  HLHS is one of the most severe congenital heart defects and is the most common cause of death in infants born with congenital heart disease.  Through this approach Dr. Grossfeld’s team has unraveled a previously unrecognized cellular mechanism underlying the pathogenesis of a subset of cases of HLHS, and have evidence suggesting that with early prenatal intervention HLHS may be preventable.   

Dr. Grossfeld’s laboratory is also identifying new genetic loci that harbor additional disease-causing genes for congenital heart defects, and will utilize similar approaches as for Jacobsen syndrome to define their function in normal heart development and disease.  Recently, his team has identified a novel gene that is required for the development of the aortic valve in humans, defects in which represent the second most common reason for open-heart surgery in adults. 


Paul Grossfeld, M.D.
Division of Pediatric Cardiology
3020 Children’s Way, MC 5004
San Diego, California  92123

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