A gene whose mutation results in malformed faces and skulls as well as mental retardation has been found by scientists

They looked at patients with Potocki-Shaffer syndrome, a rare disorder that can result in significant abnormalities such as a small head and chin and intellectual disability, and found the gene PHF21A was mutated, said Dr. Hyung-Goo Kim, molecular geneticist at the Medical College of Georgia at Georgia Health Sciences University. The scientists confirmed PHF21A's role by suppressing it in zebrafish, which developed head and brain abnormalities similar to those in patients. "With less PHF21A, brain cells died, so this gene must play a big role in neuron survival," said Kim, lead and corresponding author of the study. They reconfirmed the role by giving the gene back to the malformed fish - studied for their adeptness at regeneration - which then became essentially normal. They also documented the gene's presence in the craniofacial area of normal mice. While giving the normal gene unfortunately can't cure patients as it does zebrafish, the scientists believe the finding will eventually enable genetic screening and possibly early intervention during fetal development, including therapy to increase PHF21A levels, Kim said. It also provides a compass for learning more about face, skull and brain formation. More than a dozen of the 25,000 human genes are known to cause craniofacial defects and mental retardation, which often occur together, Kim said.