"This study identifies a previously unknown biochemical pathway involved in the regulation of blood pressure," said principal investigator Richard P. Lifton, M.D., professor of genetics, medicine, and molecular biophysics and biochemistry at Yale School of Medicine. "These findings raise the possibility that new medications affecting the activity of this pathway might be effective for treating high blood pressure and congestive heart failure."
Published in the August 10 issue of Science, the study is the most recent in a series by Lifton and his team looking at the genetics of hypertension (high blood pressure), which affects 25 percent of most adult populations and is an important risk factor for death from stroke, heart attack and kidney failure.
Lifton and his team used genetic analysis to identify the underlying cause of a rare form of hypertension called pseudohypoaldosteronism type II (PHAII) in 20 families from around the world. PHAII causes high blood pressure as well as an inability to eliminate potassium and hydrogen ions from the body. The team identified two genes that can cause the disease. Both of these genes are members of a newly identified family of proteins that regulate the activity of other proteins with the addition of phosphate groups.
Lifton said both proteins are located in a part of the kidney that is involved in the regulation of salt, potassium and pH balance. High blood pressure arises from these proteins, causing increased salt reabsorption in the kidneys and diminished secretion of potassium and hydrogen.
Lifton said one of the mutated genes he and his team discovered maps to a chromosome segment that has previously been implicated in the common form of hypertension, called essential hypertension. "This raises the possibility that more common variants in this same gene might contribute to hypertension in the general population," he said.
Lifton and his team are working with the Framingham heart study to examine the role that these newly discovered genes play in blood pressure variation in the general population. He said these new findings pave the way for better understanding of the basic causes of this common disease as well as the promise for new and improved treatments.
Other authors on the study include Frederick H. Wilson, Sandra Disse-Nicodeme, Keith A. Choate, Kazuhiko Ishikawa, Carol Nelson-Williams, Isabelle Desitter, Murat Gunel, David V. Milford, Graham W. Lipkin, Jean-Michel Achard, Morgan P. Feely, Bertrand Dussol, Yvon Berland, Robert J. Unwin, Haim Mayan, David B. Simon, Zvi Farfel and Xavier Jeunemaitre.
Lifton can be contacted at 203-737-1091 or 203-737-4420.
Journal
Science