New Gene Test May Predict Cleft Lip or Palate
Genetic Pattern Linked to About 12% of the Common Birth Defects
Aug. 18, 2004 -- A gene test may allow researchers to determine
which parents are more likely to have a second child with a cleft lip and
palate, according to a new study.
Cleft lip with or without cleft palate is one of the most
common types of birth defects worldwide, and one of the most visible. The
defects develop during fetal development and are thought to be the result of a
mix of inherited and environmental factors.
A cleft lip occurs when the tissues in the upper jaw and lip do
not join as expected during development. It often occurs in conjunction with a
cleft palate, which is the result of a similar developmental abnormality in the
roof of the mouth.
Researchers say about one in 600 children in the U.S. is born
with isolated cleft lip and palate, or a cleft lip or palate that occurs
without any other birth defects. Although the condition is usually correctible,
it requires several surgeries at great emotional and economic cost to the
In their study, researchers say they have developed a gene test
that applies to about 12% of isolated cleft lip and palate cases and can help
predict which families with a history of the birth defect are more likely to
have another child with cleft lip or palate.
"This study shows that we've reached a point where it's
possible to take blood samples from parents, test certain genes, and determine
whether their risk for a second child with cleft lip or palate is, say, 1 or 20
percent," says researcher Jeffrey Murray, MD, a scientist at the University
of Iowa, in a news release. "Now is the time to begin thinking about how
best to apply these types of tests clinically and ensure that they truly
benefit the families and their children."
Genetic Pattern Linked to Cleft Lip and Palate
In the study, published in The New England Journal of
Medicine, researchers used an international database of 1,316 families with
a child with cleft lip or palate and searched for a genetic pattern associated
with the birth defect.
Researchers isolated a distinct sequence variation in and
around the gene IRF6 that correlated with a higher chance that a second child
was born with a cleft lip or palate. The gene IRF6 is involved in disorders of
the lips, palate, skin, and genitalia.
Based on their analysis, researcher estimate that the risk of
parents with this variation having a second child with isolated cleft lip and
palate is about 12%.
"For a complex trait like cleft lip and palate, this is a
nice step forward because there may be dozens of genes that contribute to the
condition," says Murray.