title: Polymorphisms in the GRIA1 gene region in psychotic bipolar disorder.
abstract: We reported previously a significant linkage signal between psychotic bipolar disorder (BP) and microsatellite markers on chromosome 5q31-34 in the National Institute of Mental Health Bipolar Genetics Initiative (NIMH-BPGI) data set, Wave 1. In an attempt to fine-map this linkage signal we genotyped 1,134 single nucleotide polymorphisms (SNPs) under the linkage peak in 23 informative families (131 individuals) with evidence of linkage. We tested family based association in the presence of linkage with the computer software package FBAT. The most significant association in these families was with a SNP in the second intron of GRIA1 (alpha-amino-3-hydroxy-5-methyl-4-isoxazole proprionic acid (AMPA) subunit 1 receptor gene) (rs490922, Z-score = 3.3, P = 0.001). The analysis of 37 additional families with psychotic BP from NIMH-BPGI data sets, Waves 2, 3, and 4 revealed a signal at a SNP in intron 5 of the GRIA1 gene (rs4385264, Z-score = 3.2, P-value = 0.002). A combined analysis of all 60 families continued to support evidence for association of GRIA1 with psychotic BP; however, individual SNPs could not be replicated across datasets. The AMPA1 receptor has been shown to influence cognitive function, such as working memory and reward learning. Our findings suggest that variations in this receptor may contribute to the pathophysiology of BP with psychotic features in some families.
authors.affiliation: Center for Neurobehavioral Genetics, Department of Psychiatry and Biobehavioral Sciences, Semel Institute for Neuroscience and Human Behavior, University of California at Los Angeles, 90095-1761, USA. bkerner@mednet.ucla.edu
authors.forename: Berit
authors.initials: B
authors.lastname: Kerner
authors.forename: Anna J
authors.initials: AJ
authors.lastname: Jasinska
authors.forename: Joseph
authors.initials: J
authors.lastname: DeYoung
authors.forename: Maricel
authors.initials: M
authors.lastname: Almonte
authors.forename: Oi-Wa
authors.initials: OW
authors.lastname: Choi
authors.forename: Nelson B
authors.initials: NB
authors.lastname: Freimer
mesh_terms: D001714:Bipolar Disorder / Q000235:genetics*; D002895:Chromosomes, Human, Pair 5; D005838:Genotype; D006801:Humans; D020641:Polymorphism, Single Nucleotide; D018091:Receptors, AMPA / Q000235:genetics*
chemical_list: D018091:Receptors, AMPA