Novel putative nonprotein-coding RNA gene from 11q14 displays decreased expression in brains of patients with schizophrenia

A modified method of differential display was employed to identify a novel gene (named PSZA11q14), the expression of which was reduced in brains from patients with schizophrenia. Decreased expression of PSZA11q14 was identified initially in Brodmann's area (BA) 21 from a small group of patients with schizophrenia (n = 4) and normal controls (n = 6) and was confirmed subsequently using independent RT‐PCR assay in BA 21, 22, and 9, and in hippocampus from a larger group of patients with schizophrenia (n = 36) and controls (n = 35). PSZA11q14 is located on chromosome 11q14, an area shown previously to co‐segregate with schizophrenia and related disorders in several families. Decreased expression of PSZA11q14 in patients with schizophrenia and its location on 11q14 provide converging lines of evidence indicating that PSZA11q14 may be involved in at least some cases of schizophrenia. PSZA11q14 shows no significant homology with any known gene. It has no introns and produces two RNA transcripts of ∼4.5 and ∼7.0 kb. The largest open reading frame (ORF) in the PSZA11q14 transcripts may potentially encode for a short polypeptide of 71 amino acids. High frequency of rare codons, the short size of this ORF, and low homology with mouse sequences, however, indicate that PSZA11q14 may instead represent a novel member of a family of nonprotein‐coding RNA genes that are not translated and that function at the RNA level. PSZA11q14 is located within the first intron of the DLG‐2 gene and transcribed in the opposite direction to DLG‐2. These results suggest that PSZA11q14 may be considered a candidate gene for schizophrenia acting as an antisense regulator of DLG‐2, which controls assembling functional N‐methyl‐D‐aspartate (NMDA) receptors.