It is notable that genes ESR1, ESR2 and PTGS2 are shared across Alzheimer’s disease (BRCA1, PTGS2, ESR1, ESR2, BCL2 and CSF1) and Parkinson’s disease (ESR1, ESR2 and PTGS2), suggesting that they are involved in shared molecular mechanisms of neurodegeneration and inflammation in the two neurological disorders. This evidence concerns the gene BRCA1 and Parkinson disease.