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Cerebrovascular disease may be all in the family

Dr_Tromp.jpgFor Gerard Tromp, PhD, a family tree is more than just a hobby; it’s a valuable medical tool. Dr. Tromp, assistant professor in the Center for Molecular Medicine and Genetics, is identifying patients with intracranial aneurysms (IA) and investigating whether their family members may be at high risk for cerebrovascular disease. Furthermore, through genetic epidemiology and family linkages, he is attempting to define the genes that predispose certain individuals and families to intracranial aneurysms.

With more than $1.2 million from the National Institutes of Health, Dr. Tromp is expanding his preliminary reports that first-degree relatives of a person with an IA are at least four times more likely to have an aneurysm than the general population. Armed with this knowledge, Dr. Tromp considers it feasible to identify one or more genes that contribute to the increased risk. He also believes that identification of at-risk family members will allow concentration of diagnostic efforts on a smaller number of individuals and assist in early identification and repair of IAs.

"Cerebrovascular disease is the third leading cause of death in the United States and about one-quarter of cerebrovascular deaths are due to ruptured intracranial aneurysms," said Dr. Tromp. "Of those who survive the rupture, more than half are left with neurological deficits. Despite recent surgical and pharmacological advances, mortality after rupture remains very high. In contrast, however, the morbidity of elective surgery and treatment before rupture is very low--only one or two percent. Therefore, large numbers of lives will be saved and much morbidity will be prevented by identifying IAs before they occur."

Dr. Tromp and his international colleagues have collected data and DNA samples from members of 85 Finnish families in which at least two members have IAs. He is performing linkage analyses using affected family members. This part of the project has been funded in part by the Michigan Affiliate of the American Heart Association and by services provided gratis by the National Heart, Lung and Blood Institute’s Mammalian Genotyping Service.

For the follow-up studies, Dr. Tromp and his colleagues are collecting data and samples from additional families, both locally and in Finland. Locally, patients are recruited at The Detroit Medical Center in an ongoing collaboration with Dr. Fernando Diaz in the department of neurosurgery. In Finland, patients are recruited in a longstanding collaboration with Dr. Ronkainen, a neurosurgeon in Kuopio, Finland, who recruited the original 85 families and spent two years in Dr. Tromp’s laboratory working on the project to complete his PhD. Currently, WSU graduate student Sompong Vongpunsawad is working toward his thesis, by collaborating on this project.

Dr. Tromp will use the additional samples and genealogical information to assist in fine-mapping the gene or genes that seem to be responsible.

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