Researchers have identified a rare disorder that causes babies to be born with extra fingers and toes and a range of birth defects. The disorder, which has yet to be named, is caused by a genetic mutation in a gene called Max. Along with extra digits – polydactyly – it leads to various symptoms associated with ongoing brain growth, such as autism, the team from the University of Leeds in the UK said.
The study is the first to identify this genetic link. It also found a molecule that could potentially be used to treat some neurological symptoms and prevent any deterioration of their condition.
However, more research is needed to test this molecule before it can be used as a treatment.
Published in The American Journal of Human Genetics, the study focused on three individuals who have a rare combination of physical characteristics, such as polydactyly, and a much larger than average head circumference — known as macrocephaly.
Individuals also share certain characteristics, including delayed development of their eyes, which results in vision problems early in life.
Researchers compared the DNA of these individuals and found that they all carried shared genetic mutations that caused their birth defects.
“There is currently no treatment for these patients. This means that our research in rare circumstances is important not only to help us better understand them, but also to identify possible ways to treat them,” said Dr James Poulter of the University of Leeds.
“In this case, we’ve got a drug that’s already in clinical trials for another disorder—meaning we can fast-track it for these patients if the drug in our study reverses some of the effects of the mutation.
“This means that other patients with similar combinations of traits can be tested to see if they have the same variant that we identified in our study,” said Dr. Poulter.
The study team highlights the importance of interdisciplinary research in rare diseases that often face years of uncertainty for families about their child’s condition and prognosis, and provides hope for treatment.
“These are often under-presented conditions that have a huge impact on patients and their families. These families go through a long and complex diagnostic odyssey. It can take more than 10 years from their first doctor’s visit as a child to a diagnosis,” Dr. Poulter said. Dr.
“It’s important that these patients and their families discover the cause of their condition — and if they can access a therapy based on their genetic diagnosis, it can be life-changing.”
The researchers now plan to find additional patients with mutations in MAX to better understand the disorder and investigate whether potential treatments improve symptoms caused by the mutation.