Analysis of a promoter polymorphism in the SMDF neuregulin 1 isoform in Schizophrenia.
OBJECTIVE
Neuregulin 1 (NRG1) is a positional candidate gene in schizophrenia (SZ). Two major susceptibility loci in the NRG1 gene approximately one million nucleotides apart have been identified in genetic studies. Several candidate functional allelic variants have been described that might be involved in disease susceptibility. However, the findings are still preliminary. We recently mapped active promoters and other regulatory domains in several SZ and bipolar disorder (BD) candidate genes using ChIP-chip (chromatin immunoprecipitation hybridized to microarrays). One was the promoter for the NRG1 isoform, SMDF, which maps to the 3' end of the gene complex. Analysis of the SNP database revealed several polymorphisms within the approximate borders of the region immunoprecipitated in our ChIP-chip experiments, one of which is rs7825588.


METHODS
This SNP was analyzed in patients with SZ and BD and its effect on promoter function was assessed by electromobility gel shift assays and luciferase reporter constructs.


RESULTS
A significant increase in homozygosity for the minor allele was found in patients with SZ (genotype distribution chi(2) = 7.32, p = 0.03) but not in BD (genotype distribution chi(2) = 0.52, p = 0.77). Molecular studies demonstrated modest, but statistically significant allele-specific differences in protein binding and promoter function.


CONCLUSIONS
The findings suggest that homozygosity for rs725588 could be a risk genotype for SZ.
Pedrosa
Erika
E
Division of Basic Research, Department of Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
Nolan
Karen A
KA
Stefanescu
Radu
R
Herskovits
Pnina
P
Hershcovitz
Pnina
P
Novak
Tomas
T
Zukov
Ilja
I
Stopkova
Pavla
P
Lachman
Herbert M
HM
D000328:Adult; D045744:Cell Line, Tumor; D024202:Electrophoretic Mobility Shift Assay; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D009419:Nerve Tissue Proteins / Q000235:genetics* / Q000378:metabolism; D020890:Neuregulin-1; D020641:Polymorphism, Single Nucleotide; D011401:Promoter Regions, Genetic; D020033:Protein Isoforms / Q000235:genetics; D012559:Schizophrenia / Q000235:genetics*; D017422:Sequence Analysis, DNA; D014162:Transfection
C094131:NRG1 protein, human; D009419:Nerve Tissue Proteins; D020890:Neuregulin-1; D020033:Protein Isoforms