alphaSynucleinisamemberofafamilyofsmall,highlyconservedproteins,includingsynuclein-alpha,-beta,and-gamma,andsynoretin.Theseproteinsarelocalizedpredominantlyinthebrain,concentratedinpresynapticnerveterminals.Synuclein-alphaisnormallyasolubleprotein.Abnormalsynuclein-alphaformsfilamentousinclusions(LewybodiesandLewyneurites)inseveralneurodegenerativediseases,includingParkinsonsdisease(PD),dementiawithLewybodies,andAlzheimersdisease.ItisamajorcomponentofintracellularinclusionsinsporadicPD.Mutationsinthesynuclein-alphagene(A53TandA30P)havebeenreportedinseveralfamilieswithautosomaldominantParkinsonism.