Familial cerebrovascular accidents due to concomitant hyperhomocysteinemia and protein C deficiency type 1.
OBJECTIVE
Hyperhomocysteinemia and protein C deficiency are risk factors for thromboembolism. Hyperhomocysteinemia has been reported to inhibit the expression of thrombomodulin and to inactivate both thrombomodulin and protein C irreversibly, leading to decreased protein C activity.


METHODS
In a 16-year-old girl, who developed a sinus sagittalis thrombosis, and in her father, who experienced a transient ischemic attack, both hyperhomocysteinemia and protein C deficiency type 1 were present. Protein C deficiency alone was found in one of the two sisters, who was without any clinical vascular history.


CONCLUSIONS
In this family with independently inherited hyperhomocysteinemia and protein C deficiency, clinical cerebrovascular disease occurred only in those members with a combination of both risk factors, suggesting a synergistic interaction between these thrombogenic risk factors.
Department of Medicine, University Hospital Nijmegen, The Netherlands.
D G
DG
Franken
A
A
Vreugdenhil
G H
GH
Boers
A
A
Verrips
H J
HJ
Blom
I R
IR
Novakova
D000293:Adolescent; D000328:Adult; D000592:Amino Acid Metabolism, Inborn Errors / Q000150:complications* / Q000235:genetics; D002561:Cerebrovascular Disorders / Q000209:etiology / Q000235:genetics*; D005260:Female; D006710:Homocysteine / Q000097:blood / Q000378:metabolism*; D006801:Humans; D002546:Ischemic Attack, Transient / Q000209:etiology / Q000235:genetics; D008297:Male; D020151:Protein C Deficiency; D012307:Risk Factors
D006710:Homocysteine