A polymorphism in the protease-like domain of apolipoprotein(a) is associated with severe coronary artery disease
ARTERIOSCLEROSIS THROMBOSIS AND VASCULAR BIOLOGY
Authors: Luke, May M.; Kane, John P.; Liu, Dongming M.; Rowland, Charles M.; Shiffman, Dov; Cassano, June; Catanese, Joseph J.; Pullinger, Clive R.; Leong, Diane U.; Arellano, Andre R.; Tong, Carmen H.; Movsesyan, Irina; Naya-Vigne, Josephina; Noordhof, Curtis; Feric, Nicole T.; Malloy, Mary J.; Topol, Eric J.; Koschinsky, Marlys L.; Devlin, James J.; Ellis, Stephen G.
Abstract
Objectives - The purpose of this study was to identify genetic variants associated with severe coronary artery disease (CAD). Methods and Results - We used 3 case-control studies of white subjects whose severity of CAD was assessed by angiography. The first 2 studies were used to generate hypotheses that were then tested in the third study. We tested 12 077 putative functional single nucleotide polymorphisms (SNPs) in Study 1 (781 cases, 603 controls) and identified 302 SNPs nominally associated with severe CAD. Testing these 302 SNPs in Study 2 (471 cases, 298 controls), we found 5 (in LPA, CALM1, HAP1, AP3B1, and ABCG2) were nominally associated with severe CAD and had the same risk alleles in both studies. We then tested these 5 SNPs in Study 3 (554 cases, 373 controls). We found 1 SNP that was associated with severe CAD: LPA I4399M (rs3798220). LPA encodes apolipoprotein(a), a component of lipoprotein(a). I4399M is located in the protease-like domain of apolipoprotein(a). Compared with noncarriers, carriers of the 4399M risk allele (2.7% of controls) had an adjusted odds ratio for severe CAD of 3.14 (confidence interval 1.51 to 6.56), and had 5-fold higher median plasma lipoprotein(a) levels (P = 0.003). Conclusions - The LPA I4399M SNP is associated with severe CAD and plasma lipoprotein(a) levels.
Exploring the use of molecular dynamics in assessing protein variants for phenotypic alterations
HUMAN MUTATION
Authors: Garg, Aditi; Pal, Debnath
Abstract
With the advent of rapid sequencing technologies, making sense of all the genomic variations that we see among us has been a major challenge. A plethora of algorithms and methods exist that try to address genome interpretation through genotype-phenotype linkage analysis or evaluating the loss of function/stability mutations in protein. Critical Assessment of Genome Interpretation (CAGI) offers an exceptional platform to blind-test all such algorithms and methods to assess their true ability. We take advantage of this opportunity to explore the use of molecular dynamics simulation as a tool to assess alteration of phenotype, loss of protein function, interaction, and stability. The results show that coarse-grained dynamics based protein flexibility analysis on 34 CHEK2 and 1719 CALM1 single mutants perform reasonably well for class-based predictions for phenotype alteration and two-thirds of the predicted scores return a correlation coefficient of 0.6 or more. When all-atom dynamics is used to predict altered stability due to mutations for Frataxin protein (8 cases), the predictions are comparable to the state-of-the-art methods. The competitive performance of our straightforward approach to phenotype interpretation contrasts with heavily trained machine learning approaches, and open new avenues to rationally improve genome interpretation.