The specificity of the genetic pedigree we describe here consists in a SNCA triplication which also includes the six exons of Multimerin 1 (MMRN1). MMRN1 encodes for a specific Factor V/Va binding protein found in platelets and endothelium [23]. MMRN1 deficiency is associated with Factor V Quebec, an inherited bleeding disorder, although the consequences of its overexpression remain unknown. MMRN1 is not expressed in brain; thus, wild-type overexpression of alpha-synuclein appears responsible for the predominant, neurological phenotype. Here, MMRN1 is linked to hemorrhagic disease.