Increased levels of apolipoprotein E mRNA in the brains of patients with Down's syndrome

In order to study progressive dementia in Down's syndrome (DS), we analyzed the gene expression of Apolipoprotein E (apoE). ApoE mRNA levels in the br ains of patients with Down's syndrome (DS) was determined by reverse transc riptase-polymerase chain reaction (RT-PCR). ApoE genotype and the promoter polymorphisms were determined by PCR-restriction fragment length polymorphi sm (PCR-RFLP). ApoE mRNA level in the DS group was significantly higher tha n that in the control group (p<0.05). In DS, apoE mRNA levels were not sign ificantly different between apoE epsilon 4 carriers and apoE epsilon 4 non- carriers', nor did apoE promoter polymorphisms alter apoE mRNA levels. High levels of apoE mRNA in DS may play an important role in the development of Alzheimer pathology in DS.