Article

The promoter -194 C polymorphism of the nicotinic alpha 7 receptor gene has a protective effect against the P50 sensory gating deficit.

INSERM EMI 9906, IFRMP, Faculté de Médecine et de Pharmacie, Rouen, France.
Molecular Psychiatry (Impact Factor: 15.15). 03/2004; 9(3):320-2. DOI: 10.1038/sj.mp.4001443
Source: PubMed

ABSTRACT As suggested by several studies, abnormal sensory gating measured by the P50 paradigm could be an endophenotype predisposing to schizophrenia. In a previous work, we have shown a significant association between the presence of at least one -2 bp deletion located within exon 6 of the CHRNA7-like gene and the P50 abnormality in the general population. A recent study involved polymorphisms located in the core promoter region of the CHRNA7 gene as risk factors for the P50 inhibitory deficit. Screening for promoter variants in a large population of schizophrenic patients (n=111) and control subjects (85), for whom auditory-evoked potentials had been recorded did not allow us to replicate these results. By contrast, we showed a significant association between the -194 C allele and a T/C ratio <0.45, thus demonstrating a protective effect of this variant for the sensory gating deficit. Such conflicting results can be reconciled if we consider that the -194 C polymorphism has no causative effect, but is in linkage disequilibrium with other causal variations for the P50 sensory gating deficit, and that different alleles are in disequilibrium in different populations.

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