Feasibility of an affected sibling pair study in ischemic stroke - Resultsof a 2-center family history registry

Background and Purpose-We sought to determine pedigree availability for a c oncordant sibling pair study of genetic risk factors in ischemic stroke. Methods-Probands with confirmed ischemic stroke were prospectively enrolled . Family histories were obtained by systematic interview. A study neurologi st prospectively assigned stroke subtype. Results-Of 310 probands (median age, 75 years; range, 26 to 97 years; 48% w omen), 75% had at least 1 living sibling; 10%, at least 1 concordant living sibling; 2%, at least 1 concordant sibling living in the same city; and 7% , at least 1 concordant living and 1 discordant living sibling. Likelihood of having a concordant sibling increased significantly with proband age, ev en after adjustment for sibship size (P=0.002). Positive family history of stroke was not related to either proband stroke subtype or risk factor prof ile. Conclusions-Approximately 10 probands were screened to find 1 potentially c oncordant living sibling. A concordant sibling pair study should be multice ntered and enable enrollment of siblings from diverse geographic areas.