325
Combined Genetic Defect
(Homogeneity
for Factor V Leiden and
Heterogeneity
for Prothrombin G20210A
Allele),
in a
Young Patient,
with
Recurrent
Deep
Vein Thrombosis and Serious
Postphlebitic Syndrome
A Case
Report
Michael
Mitsis,
MD*
Hristos
Ioannou,
MD*
Athanasios
Eleftheriou,
MD†
Vasilios
Nousias,
MD*
Constantinos
Basioukas,
MD‡
George Kakosimos,
MD†
Charalabos
Batsis,
MD*
and
George Vartholomatos,
PhD†
IOANNINA,
GREECE
ABSTRACT
Just a few
years ago,
resistance to activated
protein
C
(APCR)
was
reported
to be of
high
significance representing
a
strong predisposing
factor in the
development
of venous
thrombosis
(VT).
A little while
later,
APCR was established to be the result of a
point
mutation of the factor V
gene (factor
V Leiden: a G-to-A transition at
position 1691). Up
to
today,
it is not certain whether factor V Leiden is in itself able to lead to
VT,
or whether
it acts in
synergy
with other factors.
Nevertheless, heterozygous subjects
have a tenfold
increase in the risk of VT when
compared
to
general population,
whereas the risk is 80
times
greater
in
homozygous
individuals. In
1996,
a
prothrombin gene
mutation
(prothrombin
G20210A
allele),
which is a
single-nucleotide
G-to-A transition at
position
20210 in the
sequence
of the 3’-untranslated
region
(3’UTR)
on chromosome
11,
was
discovered. The
presence
of this mutant
gene
results in elevated
plasma prothrombin
concentrations, increasing
the
possibility
for the
development
of VT.
However,
the coex-
(continued
on next
page)
From the
Department
of
1<Surgery, &dquo;<Laboratory
of
Hematology,
and the
+Department
of
Dermatology,
University Hospital
of
Ioannina, Ioannina,
Greece.
©2000 Westminster
Publications, Inc., 708 Glen Cove Avenue, Glen Head,
NY
11545,
U.S.A.
at East Tennessee State University on June 21, 2015 ang.sagepub.com Downloaded from