2008 Barcelona - European Society of Human Genetics

Genetic analysis, linkage, and association
P06. Genetic analysis, linkage, and
association
P06.001
Identification of novel variants in the Arylalkylamine Nacetyltransferase
(AANAT) human gene and their contribution to
mood Disorders susceptibility
V. Soria 1 , M. Gratacòs 2 , È. Martínez-Amorós 1 , J. Valero 3 , C. García 2 , J. R.
González 4 , A. Gutiérrez-Zotes 3 , E. Saus 2 , M. Bayés 2 , J. M. Crespo 1 , L. Martorell
3 , E. Vilella 3 , A. Labad 3 , J. Vallejo 1,5 , J. M. Menchón 1,5 , X. Estivill 2,6 , M. Urretavizcaya
1,5 ;
1 Mood Disorders Clinical and Research Unit, CIBER-SAM, Psychiatry Department,
Bellvitge University Hospital, Barcelona, Spain, 2 CIBERESP (CIBER en
Epidemiología y Salud Pública), Genes and Disease Program and CeGen Barcelona
Genotyping Node, Center for Genomic Regulation (CRG), Barcelona,
Spain, 3 Grup d’Investigació en Psiquiatria. Hospital Universitari Institut Pere
Mata, Rovira i Virgili University, Reus, Spain, 4 CREAL, Center for Research
in Environmental Epidemiology, Barcelona, Spain, 5 Department of Clinical
Sciences, Bellvitge Campus, Barcelona University, Barcelona, Spain, 6 Experimental
and Health Sciences Department, Pompeu Fabra University, Barcelona,
Spain.
Disruption of circadian rhythms, including abnormalities of circadian
phase position and melatonin secretion, have been described in mood
disorders (MD) but the molecular mechanisms underlying their pathology
are largely unknown . Arylalkylamine N-acetyltransferase (AANAT)
is a key enzyme involved in circadian oscillations of melatonin levels .
In order to assess the possible contribution of AANAT gene variability
to the susceptibility to MD, we systematically investigated common and
rare variation in the AANAT gene through a sequential sequencing and
single nucleotide polymorphisms (SNP)-based genotyping approach .
Our sample consists of 445 unrelated patients with MD (257 unipolar
major depressive disorder, 188 bipolar disorder) diagnosed according
to DSM-IV criteria and 440 screened control subjects . The entire coding
region, the exon-intron boundaries, the promoter and 3’UTR of the
AANAT gene were directly sequenced in a subset of 360 MD patients
by PCR, identifying 17 changes . Thirteen out of the 17 changes represent
novel sequence variations and four had been described before:
rs3760138, rs4238989, rs4646261 and rs8150 . The novel and previously
reported variants in dbSNP public database were genotyped in
the rest of the MD sample and in the control sample using SNPlex genotyping
system . Non-rare variants (MAF>2%) were further included in
a case-control association study. The results showed significant differences
in genotype distributions for two SNPs located in the promoter
region of AANAT gene (p=0.00006; p=0.004), which remained significant
after correcting for multiple comparisons . Our results suggest that
genetic variability in the promoter region of AANAT gene contribute to
the human susceptibility to mood disorders .
P06.002
Frequencies of four ABcG8 polymorphisms in patients with
ischaemic vascular diseases
A. Szilvási 1 , H. Andrikovics 1 , E. Pongrácz 2 , Á. Kalina 3 , Z. Komlósi 4 , I. Klein 5 , A.
Tordai 1 ;
1 Hungarian National Blood Transfusion Service, Budapest, Hungary, 2 Central
Hospital of Ministry of Interior, Budapest, Hungary, 3 Hospital of the National
Railways, Budapest, Hungary, 4 Semmelweis University, Budapest, Hungary,
5 Hungarian Academy of Sciences, Budapest, Hungary.
Background . ABCG5 and ABCG8 mediate sterol absorption and excretion.
It is still not clarified how the most common polymorphisms
of these genes contribute to cholesterol plasma level changes, and
whether polymorphisms are associated with multifactorial vascular
diseases .
Methods . We investigated 241 unrelated, consecutively enrolled patients
with ischaemic stroke, 148 patients with coronary heart disease
(CHD) and 191 blood donors as healthy controls for allele frequencies
(AF) of four common ABCG8 polymorphisms (D19H, Y54C, T400K,
A632V) .
Results . Linkage disequilibrium test revealed linkage between the respective
neighbouring loci of ABCG8 . Estimated haplotype frequencies
were similar for the three investigated groups (stroke or CHD
patients and healthy controls) . AFs of the investigated polymorphisms
in patient-groups showed no significant differences compared to con-
trols . There was a tendency toward reduced YY54 genotype frequency
in the entire stroke group. Upon stratification by age at disease onset,
male stroke patients under the age of 50 (n=15) showed significantly
reduced frequency of YY54 compared to control males (24 .2% vs .
41 .3%; OR:2 .205 [95%CI:1 .079-4 .504]; p=0 .0377) . No such associations
were found in female cases . In healthy controls, cholesterol levels
of individuals with YY54 genotype (n=71; median 4 .51 [25th-75th
percentiles, 4.19-5.43] mM) were significantly reduced compared to
YC54 and CC54 individuals combined (n=120; median 4 .95 [4 .42-
5.88] mM, p=0.009). In addition, we identified a new ABCG8 variant,
T401S, in a healthy control .
Conclusions . According to our data ABCG8 YY54 may be a potential
protecting factor against ischaemic stroke in young males; and Y54C
polymorphism may influence cholesterol plasma levels in healthy individuals
.
P06.003
Acetyl coA carboxylase 2 (ACACB) promoter sNP -8414 C/T is
associated with body fat in women and affects promoter activity
A. K. H. Lee 1 , T. Kyriakou 1 , D. Ge 2 , G. Liu 3 , H. Snieder 3,4 , T. D. Spector 4 , S. D.
O’Dell 1 ;
1 Nutritional Science Division, King’s College London, London, United Kingdom,
2 Center for Population Genomics and Pharmacogenetics, Duke University,
Durham, NC, United States, 3 Unit of Genetic Epidemiology and Bioinformatics,
University of Groningen, Groningen, The Netherlands, 4 Twin Research and Genetic
Epidemiology Unit, King’s College London, St Thomas’ Hospital Campus,
London, United Kingdom.
Acetyl-CoA carboxylase (ACC) catalyses the formation of malonyl-
CoA, an intermediate in fatty acid synthesis and a potent inhibitor of
carnitine palmitoyltransferase (CPT1) . CPT1 transfers long-chain fatty
acyl-CoA (LCFA-CoA) to the mitochondria for β-oxidation, so ACC
causes cytoplasmic accumulation of LCFA-CoA by increasing CPT1
inhibition . Elevated LCFA-CoA in the hypothalamus signals energy surfeit
and leads to inhibition of feeding . We proposed that genetic variation
influencing the level of expression of the ACC2 gene (ACACB)
could be influential in determining body weight. We selected -8414 C/T
(rs16939972), sited -368bp from the exon 1b transcription start site in
ACACB promoter II, as a potential functional or marker site . We tested
association with anthropometry, body fat, serum leptin, triglyceride and
insulin sensitivity in 2633 healthy Caucasian females from the Twins
UK cohort (mean age 47 .3±12 .6 y) . Allele C was associated with higher
total body fat (P=0 .014) . We then tested the activity of the promoter
with respect to -8414 C/T alleles in transfected HepG2 hepatocytes .
The constructs contained a 907bp region (from position -870 to +37
relative to the transcription start site) and were co-transfected with an
SREBP-1a expression plasmid . Activity associated with allele C was
57 .5±4 .0% and with allele T 25 .0±10 .8% of that of an SREBP-1a control
plasmid, i .e . allele C showed 2 .3 times greater activity than allele T.
ACACB could be influential in determining body weight.
P06.004
Polymorphisms in ActN3, AcE and AmPD1 genes and physical
performance in Bulgarian sub-elite athletes
S. A. Andonov 1 , R. Saraeva 2 , S. Andonova 2,3 , R. Kaneva 2,3 , V. Gigova 1 , L. Stefanov
1 , I. Kremensky 2,3 , P. Atanasov 1 ;
1 National Sports Academy “Vassil Levski”, Sofia, Bulgaria, 2 Molecular Medicine
Center, Medical University, Sofia, Bulgaria, 3 University Hospital of Obstetrics,
Sofia, Bulgaria.
The aim of this study was to analyse ACTN3 (R577X), ACE (I/D) and
AMPD1 (34C>T) polymorphisms in sub-elite athletes (n=70, 57 males
and 13 females) and controls (n=44, 15 males and 29 females) . The
correlations between genotypes and physiological and biochemical
parameters at anaerobic conditions was investigated . Athletes were
divided into three sport groups according to a power-time model of
performance intensity . The physiological parameters were evaluated
by standard Wingate Anaerobic Test and Ergospirometry . Spectrophotometry
and Blood-Gas analysis were used for the estimation of the
glycolytic enzyme activity of Lactate Dehydrogenase and Acid-Base
Balance, respectively . DNA samples was genotyped by RFLP analysis
followed by agarose gel-electrophoresis . Differences in the distribution
of alleles and genotypes between the groups were assessed by
x2-test . Statistical analysis of variances was performed using one way
ANOVA. No significant differences between the athletes and controls