2.1 Study design and assumption
The MR analysis aimed to assess the causal relationship between the
human herpes virus family and leukocytoclastic angiitis. MR analysis
relies on three fundamental assumptions:1)The genetic variants chosen as
IVs must be significantly associated with the exposure (herpes virus).
2)The IVs should not be correlated with any confounding factors. 3)The
IVs should exclusively impact the outcome (leukocytoclastic angiitis)
through the exposure, with no alternative pathways(11).