1. Evaluation of Candidate Genes as Susceptibility Genes for Left Ventricular Hypertrophy
and Cardiac Failure in Man
Shapour Jalilzadeh*; Kimbely Adams; Farahnaz Nematkhah; Martin Farrall; Hugh Watkins
Division of Cardiovascular Medicine, Radcliffe Department of Medicine
Material and Methods:
Candidate genes were genotyped in two cohorts, HTO1-2 and HTO3. Overall
345 SNPs (including htSNPs, cSNP, potentially functional SNP and singletons)
were selected to capture all possible haplotypes, functional variants and also
flanking region to cover putative regulatory elements. Haplotypes were
constructed by Haploview and htSNP were selected using Tagger. MALDI-TOF
iPLEX assay (Sequenom) was used as the method of choice due to
cost/reaction and speed up of the project. Assays were designed with
Sequenom’s MassARRAY Designer software with average plexity of 35.
Genotype calling and correction were done automatically and manually using
SpectroTYPER software. Pedstats (csg.sph.umich.edu/csg/abecasis/PedStats)
was used to validate and detect any inconsistencies in pedigree, and QTDT
(Abecasis et al. 2000) was used for statistical analysis.
Introduction:
Oxford was a member of EUGeneHeart Consortium. The goal of the EUGeneHeart project was “the development of new approaches to prevent and treat heart failure through
analysis of the genomics of signalling” and task 2 aimed at “screening for key modifiers of cardiac hypertrophy and failure”. The Oxford partner as a participant in the work package
10 was responsible for the “ Evaluation of Candidate Genes as Susceptibility Genes for Left Ventricular Hypertrophy and Cardiac Failure in Man”.
We have performed a candidate-based association study in two cohorts, HTO1-2 and HTO3 composed of British families with a history of hypertension. HTO3 is a subset of the
collection composed of ~400 individuals re-studied by MRI and ECG, 12 years after HTO1-2 collection, allowing comparison with Echo and ECG data from HTO1-2
Figure 1. Summary of HTO Family Blood Pressure study cohortsTable 1. The List of Candidate genes for association study
Conclusions:
There are strong evidences to support association findings including
transgenic animal models and data from partners in EUGeneHeart
Consortium1. Top hit genes are involved in cardiac energetics and
pathophysiology according to literature. Also data analysis suggests that a
number of families have developed Left Ventricular Hypertrophy over a 12
years period. Our findings regarding association of The rs8192678
(Gly482Ser) with LVM have been recently replicated in another population2.
Ge ne C hr Ge ne s C hr
MTHFR,CLCN6 1 MSRB3,MSR 12
CYR61 1 PIP5K2C,DTX 12
FRAP1 1 ATXN2 12
SLC16A1 1 GEFT 12
ZBTB17 1 P11,RAPGEF3 12
FGF5,FGF5 4 RAPGEF3 12
PPARGC1A 4 AKT1 14
MEF2C 5 CSK 15
LAMA4 6 MEF2A 15
PIK3CG 7 NFATC3 16
OGN,OMD 9 PLCD3,ACBD 17
C10orf 107 10 RPA1 17
CNNM2,NT5C2 10 SLC16A3 17
GHITM 10 NCOR1 17
PPP3CB 10 SMYD4 17
ILK 11 ZNF652 17
CBX5 12 AKT2 19
CBX5,HNRPA1 12 NFATC2 20
ITGA5 12 DSCR1 21
KRTHB5 12 CYBB X
LRP1 12 ITGB1BP2 X
Figure 2. PPARGC1A LD Plot and Haplotype Blocks (Haploview 4.2)
Results:
After genotyping, data comparison, imputation and Mendelian error correction, an extensive statistical analysis was performed using QTDT on HTO1-2 (Echo, ECG and IMT) and
HTO3 (ECG, MRI) to assess heritability and association. The results appeared encouraging as top signals showing association with cardiac hypertrophy indices were concentrated
in 3 functionally related genes; PPARGC1A, FRAP1 and RAPGEF3. The heritabilities were calculated for Sokolow-Lyon voltage (h2=0.32), ecglvh (h2 =0.24) and ecglvm (h2=0.14).
ECG ECG echo MRI
HTO1-2 HTO3 HTO1-2 HTO3
SNP Gene ecglvh rv5sv1 ecglvm rv5sv1 lvm lvenddiastolicvol lvendsysvolindex lvenddiasvolindex lvendsystolicvol meanlveswt totaleswt
rs2261434 FRAP1 0.0005
rs2279525 PPARGC1A 0.0006 0.0029
rs2970848 PPARGC1A 0.0017 0.0007 0.0069
rs8192678* PPARGC1A 0.003
rs2970849 PPARGC1A 0.0011 0.0007 0.0066
rs304151 MEF2C 0.0024
rs2072019 LAMA4 0.0064 0.0009
rs12206703 LAMA4 0.0059 0.0015 0.002
rs849384 PIK3CG 0.0011 0.0064
rs849387 PIK3CG 0.0089 0.006
rs10761156 OGN 0.0046 0.0013
rs7096124 GHITM 0.002 0.0013 0.008
rs11830037 RAPGEF3 0.00003
rs11170895 ITGA5 0.0005
rs653178 ATXN2 0.0071 0.004
rs7188085 NFATC3 0.0026
Table 2 . Heat map of results in excel. The rs8192678 (Gly482Ser) showed significant association with ecg-LVM
References:
1-Song X, Kusakari Y, Xiao CY, Kinsella SD, Rosenberg MA, Scherrer-Crosbie
M, Hara K, Rosenzweig A, Matsui T. mTOR attenuates the inflammatory
response in cardiomyocytes and prevents cardiac dysfunction in pathological
hypertrophy. Am J Physiol Cell Physiol. 2010 Dec;299(6):C1256-66
2-Rojek A, Cielecka-Prynda M, Przewlocka-Kosmala M, Laczmanski L, Mysiak
A1 Kosmala W. Impact of the PPARGC1A Gly482Ser polymorphism on left
ventricular structural and functional abnormalities in patients with hypertension.
J Hum Hypertens. 2014 Sep;28(9):557-63