title: Two novel presenilin-1 mutations (Y256S and Q222H) are associated with early-onset Alzheimer's disease.
abstract: Mutations in the gene encoding presenilin 1 (PS-1) account for 50% of early-onset familial Alzheimer's disease (EOFAD) cases. In this study, we identified two missense mutations in the coding sequence of the presenilin (PS-1) gene in two EOFAD pedigrees. AD was confirmed in one pedigree by autopsy. Mutation analysis of PCR products amplified from genomic DNA templates showed two novel PS-1 mutations resulting in Gln222His and Tyr256Ser. The two novel mutations are located within predicted transmembrane domains five (TM-5) and six (TM-6), respectively, and are associated with very early ages of onset. The Tyr256Ser is associated with one of the youngest age of AD onset, 25 years, which is consistent with a drastic change in function of the altered PS-1 protein. A morphometric analysis of the cortical degenerative changes of the Tyr256Ser case, showed severe involvement of the primary motor cortex, which correlated well with the pyramidal changes, including tetraspasticity. Immunoblot analysis showed the Tyr256Ser case had the greatest expression of Abeta(1-40) and Abeta(1-42), which was confirmed by ELISA, compared to other PS-1 mutant FAD cases and age-matched controls and, thus, contributes to the severity of the disease pathology.
authors.affiliation: Centre for Neurovirology and Cancer Biology, College of Science and Technology, Temple University, Philadelphia, PA 19122, USA.
authors.forename: Judith
authors.initials: J
authors.lastname: Miklossy
authors.forename: Kevin
authors.initials: K
authors.lastname: Taddei
authors.forename: Domizio
authors.initials: D
authors.lastname: Suva
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Verdile
authors.forename: Justin
authors.initials: J
authors.lastname: Fonte
authors.forename: Christopher
authors.initials: C
authors.lastname: Fisher
authors.forename: Anastazija
authors.initials: A
authors.lastname: Gnjec
authors.forename: Joseph
authors.initials: J
authors.lastname: Ghika
authors.forename: Françoise
authors.initials: F
authors.lastname: Suard
authors.forename: Pankaj D
authors.initials: PD
authors.lastname: Mehta
authors.forename: Catriona A
authors.initials: CA
authors.lastname: McLean
authors.forename: Colin L
authors.initials: CL
authors.lastname: Masters
authors.forename: William S
authors.initials: WS
authors.lastname: Brooks
authors.forename: Ralph N
authors.initials: RN
authors.lastname: Martins
mesh_terms: D000328:Adult; D000544:Alzheimer Disease / Q000235:genetics*; D019943:Amino Acid Substitution; D016229:Amyloid beta-Peptides / Q000378:metabolism; D015153:Blotting, Western; D001921:Brain / Q000378:metabolism / Q000473:pathology; D004252:DNA Mutational Analysis; D004797:Enzyme-Linked Immunosorbent Assay; D005192:Family Health; D005260:Female; D005973:Glutamine / Q000235:genetics; D006639:Histidine / Q000235:genetics; D006801:Humans; D007150:Immunohistochemistry; D008565:Membrane Proteins / Q000235:genetics*; D020125:Mutation, Missense; D010375:Pedigree; D010446:Peptide Fragments / Q000378:metabolism; D058225:Plaque, Amyloid / Q000473:pathology; D053764:Presenilin-1; D012694:Serine / Q000235:genetics; D014443:Tyrosine / Q000235:genetics
chemical_list: D016229:Amyloid beta-Peptides; D008565:Membrane Proteins; C508853:PSEN1 protein, human; D010446:Peptide Fragments; D053764:Presenilin-1; C078592:amyloid beta-protein (1-40); C075222:amyloid beta-protein (1-42); D005973:Glutamine; D014443:Tyrosine; D012694:Serine; D006639:Histidine