Is Club Feet an Inherited Condition? The Discovery of a Gene for Clubfoot

What is ClubFoot?

Club foot is a defect that appears in about 1 in every 1,000 births in the United States. In around 80% of cases the cause is unknown, but it is a complex disorder and it’s likely that several genetic mutations and environmental factors will play a role in the onset of the condition.

Children with club foot usually have one foot or both feet that point downwards and inwards. It affects the bones, tendons and muscles. There are several treatment options, but they vary depending on the child and severity of the condition. The aim is to correct the deformity whilst allowing for normal growth and development.

Is Club Feet an Inherited Condition?

To try and understand the basic genetics of club foot and find any genes that may be responsible, researchers from the Washington University School of Medicine in St. Louis studied several generations of one family. They studied the DNA of 35 family members of a patient of one of the researchers. This particular patient is a child with clubfoot in both feet.

The scientists examined the lower limbs of the relatives and took DNA samples. 13 family members were affected. When their DNA was analysed the researchers found a region on chromosome 5 that was common to all those affected. Further investigation revealed that there was a mutation on the PITX1 gene. It’s this genetic mutation that scientists believe contributes to clubfoot. The genetic mutation was also present in 3 members who were carriers for clubfoot. They did not have the condition themselves.

Previous studies have linked the gene with hind limb development in other vertebrates. In mice for example a loss of PITX1 results in shorter femur length and fewer digits on the right foot.

The discovery of at least one gene was welcome news to scientists. This is echoed by one of the authors of the study, Christina Gurnett, M.D., Ph.D., assistant professor of neurology, of pediatrics and of orthopedic surgery at the School of Medicine. “Until now, we didn’t know whether clubfoot was a muscle, nerve, spinal cord or brain problem. Now, we have an idea that clubfoot may result from mutations of genes that are involved in early limb development.”

Gene Mutations

The next stages in the research are to find out just how environment and genes interact to cause clubfoot, and of course to see if there are any other genetic mutations responsible. The team from Washington School of Medicine will also look for the frequency of genetic mutations in other families with a history of clubfoot.

Source

Washington University School of Medicine in St. Louis https://mednews.wustl.edu/news/page/normal/12803.html