European Human Genetics Conference 2007 June 16 – 19, 2007 ...

Normal variation, population genetics, genetic epidemiology
ated by blood count, liver and renal function tests. Genotype analysis
of C677T and A1289C mutations of the MTHFR gene was investigated
by PCR and restriction analysis of DNA extracted from the patients’
lymphocytes. Statistical analysis was performed using SPSS version
11.5 (ANOVA, χ 2 test). 17% of patients had genotype T/T, 47% C/T and
36% C/C for the C677T polymorphism. For the polymorphism A1289C
the findings were as follows: 38% AA, 48% AC and 14% CC. We did
not find significant difference in relative DAS28 decrease between
genotype groups 6 months after initiation of MTX therapy. MTX-related
toxicity was identified in 17 patients. According our findings the
A1289C polymorphism rendered patients sensitive to MTX toxicity.
The polymorphisms in MTHFR were not associated with any difference
in efficacy parameters during methotrexate treatment. Further
prospective studies including new genetic polymorphisms and larger
group of patients will be necessary in order to precisely assess drug
efficacy and its toxicity.
P1195. Mutation patterns of mtDNA: empirical inferences for the
coding region
C. Santos 1 , R. Montiel 1 , A. Arruda 1 , L. Alvarez 2 , M. Aluja 2 , M. Lima 1 ;
1 Department of Biology/CIRN, University of the Azores, Ponta Delgada, Portugal,
2 Department BABVE, Faculty of Sciences, Autonomous University of
Barcelona, Barcelona, Spain.
Human mitochondrial DNA (mtDNA) has been extensively used in
population and evolutionary genetics studies. Thus, a valid estimate of
human mtDNA evolutionary rate is important in many research fields.
We analysed a portion of the coding region of mtDNA between positions
3230 and 4331 (tRNA Leu , ND1 and tRNA Ile genes), using individuals
belonging to extended families from the Azores Islands (Portugal)
with the main aim of providing empirical estimations of the mutation
rate of the coding region of mtDNA under different assumptions, and
hence to better understand the mtDNA evolutionary process. Heteroplasmy
was detected in 6.5% (3/46) of the families analysed. In all of
the families the presence of mtDNA heteroplasmy resulted from three
new point mutations, and no cases of insertions or deletions were
identified. Major differences were found in the proportion and type of
heteroplasmy found in the genes studied when compared to those obtained
in a previous report for the D-loop. Our empirical estimation of
mtDNA coding region mutation rate, calculated taking into consideration
the sex of individuals carrying new mutations, the probability of
intra-individual fixation of mutations present in heteroplasmy and, to
the possible extent, the effect of selection, is similar to that obtained
using phylogenetic approaches. Based on our results, the discrepancy
previously reported between the human mtDNA coding region mutation
rates observed along evolutionary timescales and estimations obtained
using family pedigrees can be resolved when correcting for the
previously cited factors.
P1196. Allele frequencies for 150 genetic markers of oxidative
stress and myocardial infarction in Lithuania
K. Končiūtė 1,2 , V. Kučinskas 1,2 , R. Janavičius 1,2 , Z. A. Kučinskienė 3 , A. Timinskas
4 ;
1 Department of Human and Medical Genetics, Faculty of Medicine, Vilnius
University, Vilnius, Lithuania, 2 The Centre for Medical Genetics, Vilnius University
Hospital Santariškių Klinikos, Vilnius, Lithuania, 3 Department of Physiology,
Biochemistry and Laboratory Medicine, Faculty of Medicine, Vilnius University,
Vilnius, Lithuania, 4 Institute of Biotechnology, Vilnius, Lithuania.
Myocardial infarction is a complex multifactorial and polygenic disorder,
therefore large scale association studies that examine many polymorphisms
simultaneously are required to allow reliable prediction of
the genetic risk for myocardial infarction (MI).
After the large scale analysis of literature and bioinformatic databases
150 single nucleotide polymorphisms (SNPs) of 89 candidate genes,
mostly involved in oxidative stress regulation and oxidative homeostasis,
were selected to develop a microarray for arrayed primer extension
(APEX) resequencing technology (Asper Biotech, Estonia). Most
of the selected SNPs were in promoter regions or exons that might be
expected to cause changes in the function or level of expression of the
encoded protein.
The group of 49 persons from Lithuania having offspring(s) with myocardial
infarction were initially analyzed to detect the allele frequencies
for the SNPs of the candidate genes in MI. Chi square analysis
was carried out to test deviations of genotype frequencies from Hardy-
00
Weinberg equilibrium.
38 SNPs were not polymorphic in the studied group. The genotype
frequencies of SNPs of APOA5, ADRB2, LGALS2, GP1BA, ITGB3,
PDE4D, GNG12, GPX4 and NFKB1 genes deviated significantly from
those predicted by the Hardy-Weinberg equilibrium (p