Arterial and venous thrombosis in two Italian families with the factor V Arg506-->Gln mutation.
APC resistance, due to a point mutation in factor V at amino acid position Arg506, has been identified as a major cause of inherited thrombophilia. Here we report the presence of the factor V Arg506-->Gln mutation in 2 Italian families. In 1 family 3 subjects heterozygous and 2 subjects homozygous for the factor V Arg506-->Gln mutation were identified. The only subject who developed a thrombotic event was a 20-yr-old girl who was found to be homozygous for the factor V Arg506-->Gln mutation. In the second family 10 subjects were identified to be heterozygous for the factor V Arg506-->Gln mutation; among them 2 developed a thrombotic event. In the same family 2 individuals were found to be homozygous for the mutation: the first had a myocardial infarction at age 25 yr and the second suffered from multiple episodes of deep venous thrombosis and had a stroke at age 24 yr. These data show that the risk of developing deep venous thrombosis for the carriers of the factor V Arg506-->Gln mutation is high in the families investigated. Furthermore our data imply that the factor V Arg506-->Gln mutation in its homozygous form may relate to myocardial infarction and stroke.
Montaruli
B
B
Department of Medicine, University of Turin, Italy.
Voorberg
J
J
Tamponi
G
G
Borchiellini
A
A
Muleo
G
G
Pannocchia
A
A
van Mourik
J A
JA
Schinco
P
P
D000328:Adult; D001120:Arginine / Q000235:genetics*; D001483:Base Sequence; D005165:Factor V / Q000235:genetics*; D005260:Female; D005973:Glutamine / Q000235:genetics*; D006579:Heterozygote; D006720:Homozygote; D006801:Humans; D007558:Italy; D008297:Male; D008969:Molecular Sequence Data; D009154:Mutation; D009203:Myocardial Infarction / Q000235:genetics; D010375:Pedigree; D013924:Thrombophlebitis / Q000235:genetics*; D013927:Thrombosis / Q000235:genetics*
D005973:Glutamine; D005165:Factor V; D001120:Arginine