Cantu syndrome is a rare genetic disease characterized by distinct facial features, excessive hair growth, low blood pressure and an enlarged heart. About half of Cantu sufferers also have lymphedema — fluid retention and swelling in the limbs caused by a malfunctioning lymphatic system — and that is why Michael Davis, PhD, of the MU School of Medicine’s Department of Medical Pharmacology and Physiology, was drawn into the fight against the disease three years ago.
Cantu is caused by mutations that lead to hyperactive potassium ion channels. When a Washington University clinician team studying Cantu sought answers about the lymphedema issue, they connected with Davis, an international expert on the lymphatic system.
Through his study of mice with mutations causing hyperactivity of a potassium channel, Davis found that dysfunction in lymphatic muscle pumping causes their lymphedema.
Davis recently received an R01 grant from the National Institutes of Health worth $1 million over four years to study, in part, whether a potassium channel blocker called glibenclamide applied topically to the legs of afflicted mice could rescue lymphatic system dysfunction without affecting other system functions, such as insulin production. If so, the treatment could help humans with Cantu.
“What was appealing to me about this is it’s a specific cohort of patients, and nobody knew anything about why they developed lymphedema until we started,” Davis said. “Plus, my other projects are disease-related — because they are related to lymphedema — but they don’t actually involve any direct relationship to patients. This one does. I’m tied in with clinicians, and I can go every year to the clinic they have and actually meet some of these patients. That’s quite rewarding for somebody who studies mice as a basic scientist.”