High prevalence of thrombophilic traits in children with family history of thromboembolism.
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.
Calhoon
Meghan J
MJ
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.
Ross
Cassie N
CN
Pounder
Elizabeth
E
Cassidy
Danielle
D
Manco-Johnson
Marilyn J
MJ
Goldenberg
Neil A
NA
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*