Chromosome Section Deletion Leads to Epilepsy

The genetic origin of a rare human syndrome that causes cleft palate, respiratory difficulties, and epilepsy has been identified, according to a study published February 25 in Human Molecular Genetics.

After observing a mother and child who were both missing the same series of genes from their X chromosomes, researchers from the University of Pennsylvania and the Children’s Hospital of Philadelphia identified chromosomal segmental deletion as a cause of the patients’ disabilities. The team then engineered mice with the same array of disabilities as the mother and daughter, which they labeled Xq22.1 deletion syndrome. At the conclusion of the study, the animal models had the same complications as the human patients.

“This study has demonstrated that deleting this region in mice causes them to respond like humans with the same deletion,” said P. Jeremy Wang, PhD, senior author of the study and professor in the Penn School of Veterinary Medicine. “Now that we have a mouse model, we can dissect and try to genetically pinpoint which genes are responsible.”

Another similarity the scientists found between the human and animal models is the deletion syndrome seemed to affect males more than females, as all of the mice in the study died at birth due to respiratory failure. Similarly, the mother patient lost a 15-day-old son to respiratory problems. According to Wang, this results from the expression of genetic material that varies between males and females.