Dianna Milewicz, Professor, University of Texas.
HOUSTON, US: Research team at The University of Texas has found the variation that was causing the clotting problem in the case it wasn’t hemophilia. Dianna Milewicz, Professor, University of Texas collaborated with Bjorn Dahlback, MD, PhD, from Lund University, Malmo, Sweden, to pinpoint exactly how the variation was causing the clotting problem.
“No surgeon would do elective surgery because they bled too much after surgery. So we collected DNA and plasma from the family and were able to determine that a genetic variant in the Factor V gene was causing production of an abnormal form of the Factor V protein, which we called FV-Short. Factor V is a protein known to be important for the blood to clot. Dr Dahlback is a world expert on Factor V and he was very excited about the research,” said Milewicz.
“I was indeed very excited when hearing about the puzzling results because the knowledge at the time on the role of FV in coagulation could not explain the bleeding disorder. It has been a great privilege to work with Dr Milewicz and her colleagues to decode the unexpected and intriguing mechanisms on how FV-Short caused the bleeding disorder,” said Dahlback.
Genes make proteins that do everything from giving cells shape and structure to helping carry out biological processes. To make the proteins, genes go through a process called alternative splicing that creates coded portions, called exons. The researchers discovered that a mutation in exon 13 of the coagulation FV gene caused a short form of the protein due to changes in the splicing of the exons. That FV-Short protein was unexpectedly found to form a complex in blood with tissue factor pathway inhibitor (TFPI), a protein that inhibits coagulation of the blood. An overabundance of the combined FV-Short/TFPI in the bloodstream keeps the blood from clotting in the affected family members. Other researchers have been looking at ways to inhibit TFPI, which could lead to a treatment for this family’s clotting disorder.
What Milewicz called traditional genetics and “old-fashioned biochemistry” by lead co-author Lisa Vincent, PhD, led to the discovery of the FV-short protein in the blood of affected family members. Dahlback’s work determined how the FV-Short was causing the problems with clotting the blood. Milewicz said studying this family with a rare blood disorder has provided further insight into how the blood clots.
“We knew there was something wrong with these patients’ FV, but proving it required discovering unique properties of FV in coagulation. After many trials and tribulations, our true success is finally being able to provide an answer to the family about their medical issues,” said Vincent.
© The University of Texas News