No evidence for a point mutation at codon 713 and 717 of amyloid precursor protein gene in Japanese schizophrenics

Abstract

SummaryA point mutation at codon 717 of amyloid precursor protein (APP) gene has been demonstrated to play an important pathogenic role in some cases of familial Alzheimer's disease (FAD). Recently, a single case of chronic schizophrenia with a point mutation at codon 713 of APP gene which sits very close to the mutation in FAD was reported. We screened for these two kinds of mutations in 39 schizophrenic patients using polymerase chain reaction (PCR) and restriction enzyme technique. A mutation of codon 713 creates a MaelII restriction site and that of codon 717 creates a BclI site. Enzyme digestion with amplified PCR product revealed no restriction site in all subjects. None of our subjects had either of these two kinds of mutations. Our findings support the hypothesis that the case of a mutation at codon 713 of APP gene is a natural non-pathogenic variant and, as well as a mutation at codon 717, has no relation with the genetic predisposition to schizophrenia.

Protein expression of targets of the FMRP regulon is altered in brains of subjects with schizophrenia and mood disorders

“…However, the results have been equivocal (Jones et al, 1992; Coon et al, 1993; Fukuda et al, 1993; Karayiorgou et al, 1994; Morris et al, 1994; Mortilla et al, 1994; Forsell and Lannfelt, 1995). Less is known about levels of APP expression in subjects with schizophrenia, while Aβ has been shown to be reduced in cerebrospinal fluid of elderly patients with schizophrenia, supporting our results (Frisoni et al, 2011; Albertini et al, 2012).…”

A Comparison of Family History of Psychiatric Disorders Among Patients With Early- and Late-Onset Alzheimer's Disease

“…Genetic linkage studies of psychiatric disorders such as schizophrenia and bipolar disorder have pointed to potential areas of genetic chromosomal overlap with some AD genetic studies, although the results are inconsistent and conflicting. 24,25 Searches at the amyloid precursor protein locus (APP) in small sets of schizophrenic patients have had mixed results, 26 and no searches have, as of yet, been performed at the presenilin 1 or 2 locus for primary psychiatric disorders. Genetic studies of these complex psychiatric illnesses and of AD have proven difficult, primarily due to genetic and phenotypic heterogeneity.…”

A Comparison of Family History of Psychiatric Disorders Among Patients With Early- and Late-Onset Alzheimer’s Disease

“…Genetic linkage studies of psychiatric disorders such as schizophrenia and bipolar disorder have pointed to potential areas of genetic chromosomal overlap with some AD genetic studies, although the results are inconsistent and conflicting. 24,25 Searches at the amyloid precursor protein locus (APP) in small sets of schizophrenic patients have had mixed results, 26 and no searches have, as of yet, been performed at the presenilin 1 or 2 locus for primary psychiatric disorders. Genetic studies of these complex psychiatric illnesses and of AD have proven difficult, primarily due to genetic and phenotypic heterogeneity.…”