Referenced in: none

Automatically associated channels: HCN2

Title: Alteration of branch site consensus sequence and enhanced pre-mRNA splicing of an NMDAR1 intron not associated with schizophrenia.

Authors: Linda Hammond, Daniela Castanotto, Sharmon R Rice, Vishwajit L Nimgaonkar, Donna A Wirshing, John J Rossi, Leonard L Heston, Janet L Sobell

Journal, date & volume: Am. J. Med. Genet., 2002 Aug 8 , 114, 631-6

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/12210277

Abstract
Aberrant splicing of pre-mRNA is recognized to account for a significant minority of disease-causing mutations. The N-methyl-D-aspartate receptor (NMDA) subunit gene R1 (NMDAR1) is alternatively spliced to produce eight length variants. In an examination of the NMDAR1 as a candidate gene in schizophrenia, a presumed microdeletion/insertion (del/ins) was observed in intron 10 of an African-American male near a weak putative branch-site consensus sequence. Although exon 10 is not known to be alternatively spliced, the del/ins was posited to alter splicing efficiency. If splicing were abolished and intron retention occurred, an in-frame translation product of more than 250 amino acids was predicted. To explore splicing efficiency, mini genes were examined through primer-extension analyses in NIH293 embryonic kidney cell cultures. Rather than disruption of splicing, the del/ins allele exhibited a fivefold enhancement in splicing. In an association analysis with additional schizophrenic cases and unaffected controls, all of African-American descent, the mutant allele was observed at equivalent frequencies. A family study also did not support cosegregation of the variant allele with psychiatric disease.