title: High prevalence of thrombophilic traits in children with family history of thromboembolism.
abstract: OBJECTIVE
  To determine a proximate family history of venous thromboembolism (VTE) in (1) the prevalence of thrombophilia; (2) the frequency of recommended changes in management resulting from thrombophilia evaluation; and (3) outcomes in longitudinal follow-up.
  
  
  METHODS
  Laboratory thrombophilia investigation was performed in 56 children with first- or second-degree family history of thromboembolism before age 55 years, but without personal history of thromboembolism, who were enrolled in a prospective inception cohort. VTE risk factors, family history, thrombophilia findings, and management recommendations were systematically collected, along with thromboembolism risk episodes/exposures, prophylactic anticoagulation, major bleeds, and thromboembolism events during follow-up.
  
  
  RESULTS
  The frequencies of all thrombophilia traits were higher than the general population. Among 32 children who underwent complete laboratory evaluation, 34% had >or=2 traits. Thrombophilia testing led to recommendations for risk-based transient antithrombotic prophylaxis in 71% of subjects. No thromboembolism episodes developed during more than 900 patient-months of follow-up, although at-risk exposures were infrequent.
  
  
  CONCLUSIONS
  Risk-stratified approaches to primary prevention of pediatric VTE should be further evaluated in cooperative prospective studies.
authors.affiliation: Section of Hematology, Oncology, and Bone Marrow Transplantation, Department of Pediatrics, and the Mountain States Regional Hemophilia and Thrombosis Center, University of Colorado Denver and The Children's Hospital, Aurora, CO 80045, USA.
authors.forename: Meghan J
authors.initials: MJ
authors.lastname: Calhoon
authors.forename: Cassie N
authors.initials: CN
authors.lastname: Ross
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Pounder
authors.forename: Danielle
authors.initials: D
authors.lastname: Cassidy
authors.forename: Marilyn J
authors.initials: MJ
authors.lastname: Manco-Johnson
authors.forename: Neil A
authors.initials: NA
authors.lastname: Goldenberg
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D005192:Family Health; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D008297:Male; D015995:Prevalence; D011446:Prospective Studies; D019851:Thrombophilia / Q000453:epidemiology*; D054556:Venous Thromboembolism / Q000235:genetics*