title: Association of AKT1 gene variants and protein expression in both schizophrenia and bipolar disorder.
abstract: The AKT1 gene has been associated with the genetic aetiology of schizophrenia. Following the overlap model of bipolar disorder and schizophrenia, we aimed to investigate AKT1 genetic variants and protein expression in both diseases. A total of 679 subjects with European ancestry were included: 384 with schizophrenia, 130 with bipolar disorder and 165 controls. Six single nucleotide polymorphisms (SNPs) were investigated for association with the diseases using single- and multi-locus analyses. AKT1 and AKT2 protein levels were measured in post-mortem brain tissues from ante-mortem diagnosed schizophrenia (n = 30) and bipolar disorder subjects (n = 12) and matched controls. The analysis identified a significant global distortion in schizophrenia (P = 0.0026) and a weak association in bipolar disorder (P = 0.046). A sliding window procedure showed a five-SNP haplotype (TCGAG) to be associated with schizophrenia (P = 1.22 x 10(-4)) and bipolar disorder (P = 0.0041) and a four-SNP haplotype (TCGA) with the combined sample (1.73 x 10(-5)). On the basis of selected genotypes, a significant difference in protein expression emerged between subjects (P < 0.02). In conclusion, our findings, by showing the involvement of the AKT1 gene in both schizophrenia and bipolar disorder, support the role of AKT1 in the genetics of both disorders and add support to the view that there is some genetic overlap between them.
authors.affiliation: Department of Medical Genetics and Laboratory, Geneva University Hospitals and Geneva University, Chêne-Bourg, Switzerland. felicien.karege@unige.ch
authors.forename: F
authors.initials: F
authors.lastname: Karege
authors.forename: N
authors.initials: N
authors.lastname: Perroud
authors.forename: F
authors.initials: F
authors.lastname: Schürhoff
authors.forename: A
authors.initials: A
authors.lastname: Méary
authors.forename: G
authors.initials: G
authors.lastname: Marillier
authors.forename: S
authors.initials: S
authors.lastname: Burkhardt
authors.forename: E
authors.initials: E
authors.lastname: Ballmann
authors.forename: R
authors.initials: R
authors.lastname: Fernandez
authors.forename: S
authors.initials: S
authors.lastname: Jamain
authors.forename: M
authors.initials: M
authors.lastname: Leboyer
authors.forename: R
authors.initials: R
authors.lastname: La Harpe
authors.forename: A
authors.initials: A
authors.lastname: Malafosse
mesh_terms: D000328:Adult; D001714:Bipolar Disorder / Q000235:genetics* / Q000378:metabolism; D001921:Brain / Q000378:metabolism*; D016022:Case-Control Studies; D005260:Female; D056726:Genetic Association Studies; D006239:Haplotypes / Q000235:genetics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D020641:Polymorphism, Single Nucleotide; D051057:Proto-Oncogene Proteins c-akt / Q000235:genetics* / Q000378:metabolism; D012016:Reference Values; D012559:Schizophrenia / Q000235:genetics* / Q000378:metabolism; D018709:Statistics, Nonparametric
chemical_list: C494918:AKT1 protein, human; D051057:Proto-Oncogene Proteins c-akt