title: Do mood symptoms subdivide the schizophrenia phenotype? Association of the GMP6A gene with a depression subgroup.
abstract: Genetic studies of clinically defined subgroups of schizophrenia patients may reduce the phenotypic heterogeneity of schizophrenia and thus facilitate the identification of genes that confer risk to this disorder. Several latent class analyses have provided subgroups of psychotic disorders that show considerable consistency over these studies. The presence or absence of mood symptoms was found to contribute most to the delineations of these subgroups. In this study we used six previously published subtypes of psychosis derived from latent class analysis of a large sample of psychosis patients. In 280 schizophrenia patients and 525 healthy controls we investigated the associations of these subgroups with myelin related genes. After bonferroni correction we found an association of the glycoprotein M6A gene (GPM6A) with the subgroup of schizophrenia patients with high levels of depression (P-corrected = 0.006). Borderline association of the microtubulin associated protein tau (MAPT) with a primarily non-affective group of schizophrenia patients (P-corrected = 0.052) was also observed. GPM6A modulates the influence of stress on the hippocampus in animals. Thus our findings could suggest that GMP6A plays a role in the stress-induced hippocampal alterations that are found in psychiatric disorders in general and schizophrenia in particular. Overall, these finding suggests that investigating subgroups of schizophrenia based symptoms profile and particularly mood symptoms can facilitate genetic studies of schizophrenia.
authors.affiliation: Department of Psychiatry, Rudolf Magnus Institute of Neuroscience, University Medical Centre Utrecht, Utrecht, The Netherlands. mboks@umcutrecht.nl
authors.forename: Marco P M
authors.initials: MP
authors.lastname: Boks
authors.forename: Mechteld
authors.initials: M
authors.lastname: Hoogendoorn
authors.forename: Bart J
authors.initials: BJ
authors.lastname: Jungerius
authors.forename: Steven C
authors.initials: SC
authors.lastname: Bakker
authors.forename: Iris E
authors.initials: IE
authors.lastname: Sommer
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Sinke
authors.forename: Roel A
authors.initials: RA
authors.lastname: Ophoff
authors.forename: René S
authors.initials: RS
authors.lastname: Kahn
mesh_terms: D000328:Adult; D000339:Affect / Q000145:classification / Q000502:physiology*; D016022:Case-Control Studies; D015331:Cohort Studies; D003863:Depression / Q000145:classification / Q000235:genetics* / Q000473:pathology; D005260:Female; D008040:Genetic Linkage; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006624:Hippocampus / Q000473:pathology; D006801:Humans; D008297:Male; D008562:Membrane Glycoproteins / Q000235:genetics*; D008875:Middle Aged; D009419:Nerve Tissue Proteins / Q000235:genetics*; D010641:Phenotype; D020641:Polymorphism, Single Nucleotide; D012559:Schizophrenia / Q000145:classification* / Q000235:genetics* / Q000473:pathology
chemical_list: C484158:GPM6A protein, human; D008562:Membrane Glycoproteins; D009419:Nerve Tissue Proteins