WEDNESDAY, May 4 (HealthDay News) -- A gene essential to cardiac
development has been associated with a group of congenital heart
defects that cause a major proportion of childhood death from heart
It is unclear how these cardiac defects -- all malformations of
the left ventricular outflow tract (LVOT) -- develop. The new
research suggests a genetic component may play a role.
"It is estimated that there are more than 500 genes that may be important in heart development," said lead investigator Dr. Kim McBride, from the Center for Molecular and Human Genetics at The Research Institute at Nationwide Children's Hospital and a faculty member at The Ohio State University College of Medicine. "Changes in any of these genes may impact how a child's heart forms."
Researchers at the Nationwide Children's Hospital set out to
identify specific genes involved in cardiac development by
examining the DNA of children treated for left ventricular outflow
tract malformations and their parents. The study revealed a new
link between the gene ERBB4 and specific LVOT defects.
Researchers said ERBB4 encodes a protein that serves as an "on"
or "off" switch in many cellular functions during heart
"The precise defect in this very large gene is not yet known," said McBride. "ERBB4 now joins a previously identified gene, NOTCH1, as a susceptibility gene for LVOT defects. Replication of these results in other subjects will be required to better determine its role in the development of the heart malformations."
The LVOT defects include a narrowing of the aorta, a large blood
vessel that branches off the heart, which causes it to pump
abnormally hard (coarctation of the aorta) and a narrowing of the
heart's aortic valve that obstructs normal blood flow (aortic valve
They also include a rare heart defect in which the left side of
the heart is severely underdeveloped (hypoplastic left heart
syndrome), a set of four heart defects that cause inflow and
outflow problems (Shone complex) and a very rare heart defect in
which the aorta is not fully developed (interrupted aortic arch
The study appears in the journal
Birth Defects Research Part A.
The U.S. National Heart, Lung, and Blood Institute lists
detailed information on
congenital heart defects.