A gene that causes cleft lip and cleft palate, or CL/P, has been identified by researchers at the University of Colorado Health Sciences Center.
Researchers divided CL/P into two categories: sporadic and syndromic. Seventy percent of cases are sporadic. They can result from a number of factors and are difficult to trace in families.
Syndromic cases, on the other hand, may occur in many members of the same families and often are caused by mutations of specific genes. These mutations can be traced by careful study of the families, said Richard Spritz, M.D., director of the Human Medical Genetics Program at UCHSC and the study’s principal investigator.
In the August issue of Nature Genetics, Spritz and colleagues describe their study of residents of Margarita Island, Venezuela. One of every 2,000 people on the island has the syndrome associated with CL/P; this is less than the overall incidence of CL/P on the island, but the syndrome is easy to trace because it is so specific and easy to diagnose.
Researchers found that people with the CL/P syndrome had a mutation in a gene called PVRL1. They inherited this abnormal gene from each of their parents. People who inherited only one copy of the gene had only a mild upper lip abnormality.
To confirm their findings, researchers looked at a family in Israel and one in Brazil. They found that these families also had mutations in the PVRL1 gene, but the mutations were different than that found on Margarita Island.
"Now that we know this gene can cause the CL/P syndrome, we can study whether this same gene or other genes that encode similar functions might be involved in the more common, sporadic form of CL/P," said Dr. Spritz. "It’s too early to say for sure, but initial results look promising. Once we know which genes cause CL/P, then we can help families by providing more specific genetic counseling and planning, and maybe even understand how to prevent CL/P in families at risk."
