title: Biological effects of the PINK1 c.1366C>T mutation: implications in Parkinson disease pathogenesis.
abstract: PINK1 gene mutations are a cause of recessively inherited, early-onset Parkinson's disease. In some patients, a single heterozygous mutation has been identified, including the recurrent c.1366C>T transition. The interpretation of this finding remains controversial. Furthermore, the c.1366C>T mutation is associated with lower levels of PINK1 transcript, raising the question of whether mRNA levels correlate with the clinical status. We sequenced genomic DNA and copy DNA (cDNA) from 20 subjects carrying the c.1366C>T mutation in the homozygous (n = 5) or heterozygous (n = 15) state. In 17 mutation carriers, messenger RNA (mRNA) was quantified by real-time PCR using four different assays (PINK1 exon 5-6 or exon 7-8 relative to control genes SDHA or YWHAZ). Genomic sequencing confirmed the presence and zygosity of PINK1 mutations. cDNA sequencing in heterozygous mutation carriers revealed a strong wild-type and a much weaker or almost absent mutant signal, whereas in the homozygous patients, only the mutant signal was detected. Homozygous and heterozygous carriers showed PINK1 mRNA levels relative to a reference gene in the range of 0.1-0.2 and 0.5-0.6, respectively, compared with values of 0.9-1.0 in mutation-negative individuals. Treatment of lymphoblasts from a heterozygous mutation carrier with cycloheximide markedly increased the mutant transcript signal. We conclude that the recurrent PINK1 c.1366C>T mutation exerts a major effect at the mRNA level (80-90% reduction), most likely via nonsense-mediated mRNA decay. The absence of correlation between PINK1 mRNA levels and clinical status in heterozygous mutation carriers suggests that other genetic or environmental factors play a role in determining the phenotypic variability associated with the c.1366C>T mutation.
authors.affiliation: Department of Neurology, University of Lübeck, Ratzeburger Allee 160, 23538 Lübeck, Germany.
authors.forename: Anne
authors.initials: A
authors.lastname: Grünewald
authors.forename: Guido J
authors.initials: GJ
authors.lastname: Breedveld
authors.forename: Katja
authors.initials: K
authors.lastname: Lohmann-Hedrich
authors.forename: Christan F
authors.initials: CF
authors.lastname: Rohé
authors.forename: Inke R
authors.initials: IR
authors.lastname: König
authors.forename: Johann
authors.initials: J
authors.lastname: Hagenah
authors.forename: Nicola
authors.initials: N
authors.lastname: Vanacore
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Meco
authors.forename: Angelo
authors.initials: A
authors.lastname: Antonini
authors.forename: Stefano
authors.initials: S
authors.lastname: Goldwurm
authors.forename: Suzanne
authors.initials: S
authors.lastname: Lesage
authors.forename: Alexandra
authors.initials: A
authors.lastname: Dürr
authors.forename: Ferdinand
authors.initials: F
authors.lastname: Binkofski
authors.forename: Hartwig
authors.initials: H
authors.lastname: Siebner
authors.forename: Alexander
authors.initials: A
authors.lastname: Münchau
authors.forename: Alexis
authors.initials: A
authors.lastname: Brice
authors.forename: Ben A
authors.initials: BA
authors.lastname: Oostra
authors.forename: Christine
authors.initials: C
authors.lastname: Klein
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Bonifati
mesh_terms: D001483:Base Sequence; D003596:Cytosine; D018076:DNA, Complementary / Q000235:genetics; D005190:Family; D005260:Female; D006580:Genetic Carrier Screening; D006720:Homozygote; D006801:Humans; D008297:Male; D009154:Mutation; D010300:Parkinson Disease / Q000201:enzymology / Q000235:genetics*; D016133:Polymerase Chain Reaction / Q000379:methods; D020641:Polymorphism, Single Nucleotide; D011494:Protein Kinases / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics; D013941:Thymine; D000099202:PTEN-Induced Putative Kinase
chemical_list: D003596:Cytosine; D018076:DNA, Complementary; D011494:Protein Kinases; D012333:RNA, Messenger; D013941:Thymine; D000099202:PTEN-Induced Putative Kinase