The disorder is known as short-rib polydactyly syndrome (SRPS). The foetus develops extra fingers and toes and its skeleton does not grow, resulting in stunted ribs that prevent the lungs from maturing in the womb.
Unable to breathe, the child dies shortly after birth.
Parents currently must wait until the second trimester of pregnancy for a diagnosis - a long time to wait for potentially agonising news about one's unborn child.
"Now that we've identified the genetic basis of the disease, families will be able to obtain a prenatal diagnosis within about 12 weeks," said Deborah Krakow, orthopaedic surgeon and human geneticist, David Geffen School of Medicine, University of California Los Angeles (UCLA).
"Parents will also be able to screen embryos conceived in vitro to help select those free of the genetic mutation before uterine implantation."
Roughly, one in 300 people are carriers of SRPS. Both parents must carry the mutated gene in order for their child to inherit the disease.
The UCLA team studied DNA samples from three families whose children died of SRPS. Stan Nelson, UCLA professor of human genetics, and his lab employed powerful genomic technology to rapidly test hundreds of thousands of gene variations in each foetus.
"It took scientists 10 years to map the human genome," Nelson said. "New technology enables us to search a child's entire genome in two weeks without testing the parents or other family members. It's a highly efficient way to quickly sample DNA and identify shared gene variations among people."
In this study, researchers identified a DNA sequence shared by all three infants from a single family. Like a signpost, it directed the scientists to a chromosomal location they suspected of housing the disease-causing gene, said an UCLA release.
These findings were published in the Wednesday online edition of the American Journal of Human Genetics.
copyright 2009 by IANS.