Pitt researchers awarded $11.8 million NIH grant to explore genetic roots of cleft lip, palate

$11.8 Million Grant from the NIH Supports Research at Pitt's School of Dental Medicine

Researchers at the University of Pittsburgh School of Dental Medicine have been awarded a $11.8 million, five-year grant from the National Institute of Dental and Craniofacial Research, part of the National Institutes of Health, to continue their exploration of the genetic roots of cleft lip and cleft palate and to expand the effort to include populations in Colombia, Nigeria, the Philippines and Pennsylvania.

Orofacial clefts (OFCs), which are small gaps in the lip or palate that can form when a baby's mouth doesn't develop properly during pregnancy, occurs in 1 out of 700 live births worldwide, said Mary L. Marazita, Ph.D., professor and vice chair, Department of Oral Biology, and director of the Center for Craniofacial and Dental Genetics (CCDG).

"Orofacial clefts present a significant public health challenge as these patients typically require surgical, nutritional, dental, speech and behavioral treatments for years," Dr. Marazita said. "We hope to build on the progress we've made in our previous studies by identifying genetic susceptibility not only for the overt defects, but also for more subtle features such as changes in facial structure that we have found in relatives of participants with OFCs."

Dr. Marazita and Seth M. Weinberg, Ph.D., assistant professor of oral biology, and director of the CCDG Imaging and Morphometrics Lab, lead the coordinating center for the project, which includes researchers from the University of Iowa, the Newborn Screening Foundation in the Philippines, the Lancaster Cleft Palate Clinic, Nigeria's University of Lagos, Colombia's Foundation Clinica Noel, and KU Leuven University in Belgium.

For the work's next phase, the team will recruit for genetic studies about 6,100 individuals from more than 1,500 families with a history of cleft lip with or without cleft palate, or cleft palate alone, from a low-risk population in Nigeria; high-risk populations in the Philippines and Colombia; and mid-risk populations in Pittsburgh and Lancaster, Pa., as well as 2,000 unrelated individuals with no history of OFC.

"Recent studies indicate different genes seem to be involved in different ethnic groups, so we must broaden our perspective to understand the factors that lead to clefts," Dr. Weinberg said. "We have limited information about the development of cleft palate alone, for example. This research effort will greatly add to our knowledge."

The team also will assess participants for subclinical manifestations of genetic predisposition for OFCs with high-resolution ultrasound scanning of mouth muscles, lip print patterns, 3-D imaging of facial surfaces and more. Their previously published studies have shown that relatives of OFC patients are more likely to have subtle defects in the orbicularis oris muscle around the mouth, and facial differences such as mid-face retrusion and wider faces. OFC patients also report a family history of cancer more often than unaffected individuals, noted Dr. Marazita.

"Minor dental abnormalities, facial shape differences, altered speech patterns and other less obvious changes in the mouth could all be part of a spectrum of defects that have the same genetic causes as cleft lip and palate," she said.

"If we can unravel those relationships and identify the biological pathways that cause them, we will gain insights that may lead to better treatments and better long-term outcomes for affected individuals."