题目:Genetic Etiology for Alcohol-Induced Cardiac Toxicity
作者:J. S. Ware等
期刊:Journal of the American College of Cardiology
发表时间:2018年5月
DOI:10.1016/j.jacc.2018.03.462
网址:https://www.sciencedirect.com/science/article/pii/S073510971834172X?via%3Dihub
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一. 研究人群
141例ACM患者,招募自6家西班牙的医院
ACM定义:DCM with a history of prolonged and heavy alcohol consumption: that is, a self-reported history of alcohol intake of >80 g/day over a period ofat least 5 years, with excess intake continuing up to no <3 months before initial diagnosis of ACM.
DCM定义为:LV dilation and reduced EF in the absence of CAD (invasive or CT angiographic evidence of >50% stenosis in any major epicardial coronary artery, or previous PCI or CABG) or abnormal loading conditions (uncontrolled hypertension of significant primary valvular disease).
对照人群
DCM患者:经late gadolinium enhancement cardiac magnetic resonance were prospectively enrolled in the Royal Brompton Hospital Cardiovascular Research Centre Biobank between 2009 and 2015。其中选出366例unrelated cases matched both technically and by ethnicity with the ACM cohort.
健康对照:445例健康对照者,recruited prospectively via advertisement to the I.K. Digital Heart Project at the MRC-LMS, Imperial College London.
二. 方法
分析的基因
TTN, DSP, MYH7, LMNA, TNNT2, TCAP, SNC5A,BAG3, TNNC1
选这9个基因是因为:demonstrated excess of rare variation in DCM clinical cohorts over ExAC reference samples, for either truncating or non-truncating variants.
测序方法
Illumina TruSight Cardio Sequencing kit,测序平台Illumina NextSeq
Agilent SureSelect XT target capture,测序平台SOLiD 5500XL
突变筛选与注释variant filtering and annotation
Computational and predictive data:Variant Effect Predictor, VEP
Population data:ExAC allele frequency <8.4 × 10E−5
三. 结果
1) 141例ACM患者中,有19例发现了4个基因上的20个不同的突变。其中14例患者携带TTNtv。
其余6个突变为:1个BAG3tv,1个BAG3无义突变,1个TTNtv+LMNA错义突变,3个MYH7突变。
2) ACM患者中携带TTNtv和不携带TTNtv的患者在phenotype及demographics无显著差异,除了心脏病家族史。
3) In multivariable analysis accounting for covariate predictors of baseline LVEF, neither TTNtv nor excess alcohol consumption were significant predictors in isolation, but patients withboth TTNtv and excess alcohol consumption (n = 13) had a statistically significant and biologically important reduction in LVEF
四. 结论
作者在141例ACM患者中发现了19个罕见的protein-altering突变,该频率与DCM患者相当,且显著高于对照人群。因此认为一部分ACM具有遗传因素的病因。作者进一步支持了该模型,即酒精摄入与遗传因素相互作用,导致了ACM的产生以及加重了DCM。
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瞎想
假设最开始的问题是“ACM是否由遗传因素所致”,那应该做什么研究。
先分别澄清这个问题中的词语的具体定义,“ACM”如原文中所述为excess alcohol consumption + DCM-like phenotype。“遗传因素”这里特指基因,具体的说是基因序列(把序列单独抽离出来,作为一层)。“所致”或者“导致”,先规定为:如果发生事件A/带有性质a,B一定为真/非常可能为真;如果B为真,事件A/性质a一定/非常可能为真,那么说A/a导致B(这个含义与“导致”的用法不太一致,需再次审查)。
把“ACM”和“遗传因素”分别缩小为“有一种ACM”和“有一个遗传因素(有一个DNA序列)”,那么原来问题缩小为“存在一种ACM(记为ACMX),是由某一个DNA序列(记为VARX)所致”(问题缩小时被忽略的部分仍然是个大问题)。即,对于所有的ACMX中,均有VARX;对于所有的VARX,均表现为ACMX。但是我们既不知道ACMX,也不知道VARX。甚至满足上述条件的ACMX-VARX关系对不存在或者说需要更严格的限定条件。
假设存在这样的ACMX-VARX。我们在现实中根据样本可以建立关系对ACMa-VARa、ACMb-VARb、ACMc-VARc…。完整的关系对表要穷尽所有存在的个体,但是不可能。【思路受阻】