

# Two sample MR report

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## Phosphatidylcholine (O-16:0_20:3) levels against Malignant_melanoma_of_skin

Date: **04 January, 2026**

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### Results from two sample MR:


|method                    | nsnp|         b|        se|      pval|
|:-------------------------|----:|---------:|---------:|---------:|
|MR Egger                  |    3| 0.3241228| 0.3045313| 0.4801666|
|Weighted median           |    3| 0.2667610| 0.0907731| 0.0032952|
|Inverse variance weighted |    3| 0.2767157| 0.0777523| 0.0003724|
|Simple mode               |    3| 0.2614829| 0.1075437| 0.1355859|
|Weighted mode             |    3| 0.2631650| 0.1003371| 0.1197996|

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### Heterogeneity tests


|method                    |         Q| Q_df|    Q_pval|
|:-------------------------|---------:|----:|---------:|
|MR Egger                  | 0.1369120|    1| 0.7113704|
|Inverse variance weighted | 0.1628357|    2| 0.9218084|

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### Test for directional horizontal pleiotropy


| egger_intercept|        se|     pval|
|---------------:|---------:|--------:|
|      -0.0098522| 0.0611904| 0.898371|

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### Test that the exposure is upstream of the outcome


| snp_r2.exposure| snp_r2.outcome|correct_causal_direction | steiger_pval|
|---------------:|--------------:|:------------------------|------------:|
|       0.0003502|              0|TRUE                     |    0.1395182|

Note - R^2 values are approximate

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### Forest plot of single SNP MR

![plot of chunk chunk5](figure/Phosphatidylcholine_O160203_levels_against_Malignantmelanomaofskinchunk5-1.png)

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### Comparison of results using different MR methods

![plot of chunk chunk6](figure/Phosphatidylcholine_O160203_levels_against_Malignantmelanomaofskinchunk6-1.png)

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### Funnel plot

![plot of chunk chunk7](figure/Phosphatidylcholine_O160203_levels_against_Malignantmelanomaofskinchunk7-1.png)

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### Leave-one-out sensitivity analysis

![plot of chunk chunk8](figure/Phosphatidylcholine_O160203_levels_against_Malignantmelanomaofskinchunk8-1.png)
