The association between weight at birth and breast cancer risk revisited using Mendelian randomisation
Observational studies suggest that higher birth weight (BW) is associated with increased risk of breast cancer in adult life. We conducted a two-sample Mendelian randomisation (MR) study to assess whether this association is causal. Sixty independent single nucleotide polymorphisms (SNPs) known to be associated at P < 5 × 10 −8 with BW were used to construct (1) a 41-SNP instrumental variable (IV
