Genes that cause heart defects in children `identified`

Updated: Mar 31, 2011, 00:00 AM IST

Melbourne: Scientists have discovered a new group of genes which they claim could be responsible for causing heart defects in kids.

A team, led by Victor Chang Cardiac Research Institute in Sydney, has found that as well as genes that are active in the heart as it forms, those not directly involved in heart`s
development can also cause a congenital heart defect.

"Up until now, scientists around the world have identified gene abnormalities, or mutations, in a number of cases of congenital heart disease (CHD), by looking at those
genes that are active in the heart as it`s developing – the logical place one would search.
"What our research shows, is that we now must widen that search, to include genes that are active outside the heart as it forms, elsewhere in the embryo, because they
may also impact on the heart`s formation," said Prof Sally Dunwoodie, who led the team.

Using a mouse model, the team revealed that a genecalled Cited2 is active in the heart during development, but its activity there plays no role in normal heart formation.

Rather, it`s its earlier activity in embryonic tissue, before the primitive heart develops, that can affect subsequent formation of the heart and result in defects at birth.

Heart disease in children can range from a relatively simple hole in the heart to a complex range of conditions that can either cause the developing baby to die in the womb, or
can severely affect the heart`s rhythm and blood flow.

Prof Dunwoodie said that this research could help identify a far greater range of causes for CHD, underpinning better treatment for patients and improving genetic
counselling for families.

"Cures for heart disease in children are rare. A number of surgical techniques are available to improve quality of life for kids with heart disease, but in many cases this
involves massive and repeated surgery on tiny babies.

"So early intervention and genetic testing to see if family members are likely to have a baby with a heart defect, are where the real differences are going to be made,"she said.
The findings have been published in the latest edition of the `Human Molecular Genetics` journal.

PTI