Abstract: Specific polymorphisms in BChE gene have been found which allow determining whether a patient suffers from dementia with Lewy bodies (DLB), and allow distinguishing it from Alzheimer's disease. The invention provides an in vitro method for the diagnosis of DLB comprising determining in a biological sample from a subject, the genotype of the following polymorphisms in butyrylcholinesterase (BChE) gene: the polymorphic site at position 3687 in NCBI Accession Number NG_009031 (i.e. SEQ ID NO: 1) the polymorphic site at position 4206 in SEQ ID NO: 1, the polymorphic site at position 4443 in SEQ ID NO: 1. and the polymorphic site at position 68974 in NCBI Accession Number NG_009031 (i.e. position 934 in SEQ ID NO: 26).

Abstract: Specific alterations in BChE gene have been found which allow determining whether a patient suffers from dementia with Lewy bodies (DLB), and allow distinguishing it from Alzheimer's disease. The invention provides an in vitro method for the diagnosis of DLB comprising determining in a biological sample from a subject, the genotype of the following alterations in butyrylcholinesterase (BChE) gene: the polymorphic sites at position 68974 in NCBI Accession Number NG_009031 (i.e. position 934 in SEQ ID NO: 28), and the polymorphic sites 3687, 4206, 4443, and the poly-thymine region at positions 4780 to 4786, said positions with reference to NCBI Accession Number NG_009031 (i.e. positions 3687, 4206 and 4443 respectively in SEQ ID NO: 1), which corresponds to the nucleotide sequence of human BChE gene.