C to T nucleotide substitution in codon 713 of amyloid precursor protein gene not found in 86 unrelated schizophrenics from multiplex families.

Jones et al. Nature Genet 1:306-309, [1992] recently detected a C to T nucleotide transition (codon 713) in a highly conserved region of the beta-amyloid precursor gene in a single case of schizophrenia. Although the sequence variant may be a natural polymorphism, it is crucial to determine whether the mutation might be present in a small subset of schizophrenics. We isolated DNA from 86 unrelated chronic schizophrenics who had a first degree relative with chronic schizophrenia or chronic schizoaffective disorder. After PCR amplification of exon 17, we were unable to detect the presence of the codon 713 variant in these schizophrenic cases, as well as in 156 controls. Unless additional cases are found with the codon 713 mutation, it is unlikely that the sequence variant is pathogenic for schizophrenia.