Schizophrenic women with the APOE ε4 allele have a worse prognosis than those without it

Abstract

The ⑀4 allele of APOE is generally accepted to be a risk factor in Alzheimer's disease and it has been related to other neuropsychiatric disorders, including schizophrenia. The results of several case-control studies have been inconclusive. To shed more light on this issue we carried out an association study that compared the APOE common variant in a group of 365 schizophrenia patients and 584 controls. We found no differences in the genotype distributions and allele frequencies of patients and controls. In the group of patients, we also analysed the possible influence of the ⑀4 allele in the clinical variables. The most important findings are that the age at onset (AAO) of ⑀4+ schizophrenic women, those that have one or two ⑀4 alleles, is 4 years earlier than that of ⑀4− women and their risk of suffering a negative syndrome subtype is four times greater. This was not found in schizophrenic men. Our results show that the APOE variant is not a risk factor for developing schizophrenia but that it may modulate its phenotypic expression in a sex-dependent manner. Molecular Psychiatry (2001) 6, 307-310.

Apolipoprotein E polymorphism is associated with age of onset in schizophrenia

“…However, in the study by Arnold et al (1997), a linear association between age of onset and APOE genotype was found, and e3 allele was regarded as a neutral factor regarding age of onset. Martorell et al also reported an association between the presence of e4 allele and early age of onset in women (Martorell et al 2001). Our findings suggest that e3 allele serves as a protective factor, and its absence could be associated with a higher risk for early-onset schizophrenia, whereas e4 allele is a risk factor for earlier onset.…”

“…Early age of onset in schizophrenia has been associated with an excess of e4 allele in two different samples (Arnold et al 1997;Martorell et al 2001), but in the study by Igata-Yi et al, the frequency of e4 was lower in the early onset group . Saiz et al reported no association between the frequency of e4 and age of onset (Saiz et al 2002).…”

Possible effect of the APOE ε4 allele on the hippocampal volume and asymmetry in schizophrenia

“…The e4 allele was reported to be associated with younger age of onset [Arnold et al, 1997] and lower scores of psychotic symptoms [Pickar et al, 1997]. Furthermore, a recent study of Martorell et al [2001] reported younger age of onset and greater risk of suffering a negative syndrome subtype in schizophrenic women carrying the e4 allele compared to those without the allele.…”

Depression in Alzheimer’s Disease Might Be Associated with Apolipoprotein E ε4 Allele Frequency in Women but Not in Men

“…After the Â4 allele had been established as a risk factor in AD, some investigators looked more closely at Â4 as a possible risk factor for other psychiatric or neurologic disorders [11][12][13]. In particular, the role of Â4 in geriatric depression and non-cognitive syndromes in AD and other dementias was investigated.…”