Objective: To investigate the association between apolipoprotein E (ApoE) genotype and schizophrenia.
Method: We genotyped 106 schizophrenic out-patients [Diagnostic Statistic Manual IV (DSM-IV) criteria] and 250 healthy volunteers (hospital staff and blood donors) from Asturias (Northern Spain). The ApoE genotypes (ϵ2, ϵ3, ϵ4 – alleles) were determined after polymerase chain reaction (PCR) amplification, followed by digestion with the restriction enzyme CfoI and electrophoresis on a 4% agarose gel.
Results: No significant differences in ApoE-allele frequencies between patients and controls was found, although an increased ϵ4-frequency was recorded in patients compared with controls [9.0% vs. 6.2%, P=0.124; odds ratio (OR)=1.49; 95% confidence interval (CI)=0.82–2.70]. ApoE-genotype frequencies did not differ between both groups. The mean age of onset for schizophrenic patients that carried the ϵ4-allele was not significantly different from that of patients without this allele.
Conclusion: Variation in the ApoE gene was not associated with the development of schizophrenia in our population. ApoE-genotypes did not modify the age of onset of the disease.