Screening schizophrenic patients for mutations in the amyloid precursor protein gene.

A limited number of rare missense mutations in exons 16 and 17 of the amyloid precursor protein (APP) gene have been reported. They are associated with a variety of phenotypes including cerebral haemorrhage, multi-infarct dementia and Alzheimer's disease. We recently reported an alanine to valine mutation in codon 713 in a single case of chronic familial schizophrenia with cognitive deficits. Using denaturing gradient gel electrophoresis (DGGE) we have screened a cohort of 250 chronic schizophrenics for further mutations of exons 7, 16 and 17. None were found. Nevertheless recent evidence suggests that the 713 mutation is indeed pathogenic for the clinical phenotype observed; the mechanisms involved are outlined.