Package 'MRPRESSO'

Title: Performs the Mendelian Randomization Pleiotropy RESidual Sum and Outlier (MR-PRESSO) test.
Description: MR-PRESSO (Mendelian Randomization Pleiotropy RESidual Sum and Outlier) is a framework that allows for the evaluation of pleiotropy in multi-instrument Mendelian Randomization utilizing genome-wide summary association statistics.
Authors: Marie Verbanck
Maintainer: Marie Verbanck <[email protected]>
License: GPL-3
Version: 1.0
Built: 2024-09-17 02:25:00 UTC
Source: https://github.com/rondolab/MR-PRESSO

Help Index


Performs the Mendelian Randomization Pleiotropy RESidual Sum and Outlier (MR-PRESSO) test.

Description

MR-PRESSO (Mendelian Randomization Pleiotropy RESidual Sum and Outlier) is a unified framework that allows for the evaluation of pleiotropy in a standard MR model. The method extends on previous approaches that utilize the general model of multi-instrument MR on summary statistics. MR-PRESSO has three components, including: 1) detection of pleiotropy (MR-PRESSO global test); 2) correction of pleiotropy via outlier removal (MR-PRESSO outlier test); and 3) testing of significant distortion in the causal estimate before and after MR-PRESSO correction (MR-PRESSO distortion test).

Details

The DESCRIPTION file:

Package: MRPRESSO
Type: Package
Title: Performs the Mendelian Randomization Pleiotropy RESidual Sum and Outlier (MR-PRESSO) test.
Version: 1.0
Date: 2017-06-29
Author: Marie Verbanck
Maintainer: Marie Verbanck <[email protected]>
Description: MR-PRESSO (Mendelian Randomization Pleiotropy RESidual Sum and Outlier) is a framework that allows for the evaluation of pleiotropy in multi-instrument Mendelian Randomization utilizing genome-wide summary association statistics.
License: GPL-3
NeedsCompilation: no
Packaged: 2017-29-01 12:14:11 UTC; verbam01
Repository: https://mrcieu.r-universe.dev
RemoteUrl: https://github.com/rondolab/MR-PRESSO
RemoteRef: HEAD
RemoteSha: 3e3c92d7eda6dce0d1d66077373ec0f7ff4f7e87

Index of help topics:

MRPRESSO-package        Performs the Mendelian Randomization Pleiotropy
                        RESidual Sum and Outlier (MR-PRESSO) test.
SummaryStats            Simulated toy dataset
mr_presso               a function to perform the Mendelian
                        Randomization Pleiotropy RESidual Sum and
                        Outlier (MR-PRESSO) test

Author(s)

Marie Verbanck

Maintainer: Marie Verbanck <[email protected]>

References

Detection of widespread horizontal pleiotropy in causal relationships inferred from Mendelian randomization between complex traits and diseases. Marie Verbanck, Chia-Yen Chen, Benjamin Neale, Ron Do. Nature Genetics 2018. DOI: 10.1038/s41588-018-0099-7. https://www.nature.com/articles/s41588-018-0099-7

Examples

data(SummaryStats)
mr_presso(BetaOutcome = "Y_effect", BetaExposure = "E1_effect", SdOutcome = "Y_se", SdExposure = "E1_se", OUTLIERtest = TRUE, DISTORTIONtest = TRUE, data = SummaryStats, NbDistribution = 1000,  SignifThreshold = 0.05)

a function to perform the Mendelian Randomization Pleiotropy RESidual Sum and Outlier (MR-PRESSO) test

Description

MR-PRESSO (Mendelian Randomization Pleiotropy RESidual Sum and Outlier) is a unified framework that allows for the evaluation of pleiotropy in a standard MR model. The method extends on previous approaches that utilize the general model of multi-instrument MR on summary statistics. MR-PRESSO has three components, including: 1) detection of pleiotropy (MR-PRESSO global test); 2) correction of pleiotropy via outlier removal (MR-PRESSO outlier test); and 3) testing of significant distortion in the causal estimate before and after MR-PRESSO correction (MR-PRESSO distortion test).

Usage

mr_presso(BetaOutcome, BetaExposure, SdOutcome, SdExposure, data, OUTLIERtest = FALSE, DISTORTIONtest = FALSE, SignifThreshold = 0.05, NbDistribution = 1000, seed = NULL)

Arguments

BetaOutcome

character, name of the outcome variable

BetaExposure

vector of characters, name(s) of the exposure(s)

SdOutcome

character, name of the standard deviation of the outcome variable

SdExposure

vector of characters, name(s) of the standard deviation of the exposure(s)

data

dataframe of summary statistics containing the outcome and exposure variables

OUTLIERtest

boolean, if TRUE the MR-PRESSO outlier test will be performed, default is FALSE

DISTORTIONtest

boolean, if TRUE the MR-PRESSO distortion test on the causal estimate will be performed, default is FALSE

SignifThreshold

float, significance threshold to use between 0 and 1, default is 0.05

NbDistribution

integer, number of elements to simulate to form the null distribution to compute empirical P-values. This is directly impacting the precision of the empirical P-values, it is 1/NbDistribution for the global test and nrow(data)/NbDistribution

seed

a single value, interpreted as an integer to use in set.seed()

Value

Main MR results

Results of the MR analysis providing the causal estimate, sd and P-value of the raw and outlier-corrected MR analysis

Global Test

Results of the MR-PRESSO global test. List of the observed residual sum of squares 'RSSobs' and empirical P-value 'Pvalue'

Outlier Test

Results of the MR-PRESSO outlier test. Table of observed residual sum of squares 'RSSobs' and 'Pvalue' per SNV

Distortion Test

Results of the MR-PRESSO distortion test. List of the 'Outliers Indices' identified as outliers and excluded to calculate the 'Distortion Coefficient' (in percent) and its 'Pvalue'.

Author(s)

Marie Verbanck

References

Detection of widespread horizontal pleiotropy in causal relationships inferred from Mendelian randomization between complex traits and diseases. Marie Verbanck, Chia-Yen Chen, Benjamin Neale, Ron Do. Nature Genetics 2018. DOI: 10.1038/s41588-018-0099-7. https://www.nature.com/articles/s41588-018-0099-7

Examples

data(SummaryStats)
mr_presso(BetaOutcome = "Y_effect", BetaExposure = "E1_effect", SdOutcome = "Y_se", SdExposure = "E1_se", OUTLIERtest = TRUE, DISTORTIONtest = TRUE, data = SummaryStats, NbDistribution = 1000,  SignifThreshold = 0.05)

Simulated toy dataset

Description

'SummaryStats' is a simulated toy dataset of summary statistics for Y the outcome and E1 and E2 two exposures. It is composed of 45 single ncleotide variants (SNVs) associated with E1 and 5 additional variants associated with E1 and E2 which are therefore submitted to pleiotropy. Test the function mr_presso() on this toy dataset.

Usage

data("SummaryStats")

Format

A data frame with 50 observations on the following 9 variables.

E1_effect

a numeric vector

E1_se

a numeric vector

E1_pval

a numeric vector

E2_effect

a numeric vector

E2_se

a numeric vector

E2_pval

a numeric vector

Y_effect

a numeric vector

Y_se

a numeric vector

Y_pval

a numeric vector

References

Detection of widespread horizontal pleiotropy in causal relationships inferred from Mendelian randomization between complex traits and diseases. Marie Verbanck, Chia-Yen Chen, Benjamin Neale, Ron Do. Nature Genetics 2018. DOI: 10.1038/s41588-018-0099-7. https://www.nature.com/articles/s41588-018-0099-7

Examples

data(SummaryStats)
mr_presso(BetaOutcome = "Y_effect", BetaExposure = "E1_effect", SdOutcome = "Y_se", SdExposure = "E1_se", OUTLIERtest = TRUE, DISTORTIONtest = TRUE, data = SummaryStats, NbDistribution = 1000,  SignifThreshold = 0.05)