Experience of ApoE Study in Thai Elderly
VORAPUN SENANARONG, M.D., MRCP (UK)*, KAMOLTIP HARNPHADUNGKIT, M.D."'*• PATCHAREE LERTRIT, M.D., Ph.D.,***, CHALERMCHAI MITRPANT, B.Sc. ***, SUTHIPOL UDOMPUNTHURAK, B.Sc., M.Sc. ****, CHANIN LIMWONG, M.D.*****, NARAPORN PRAYOONWIWAT, M.D.*, NIPHON POUNGV~ RIN, M.D., FRCP (London)*
Affiliation : * Division of Neurology, Department of Medicine, ** Department of Rehabilitation Medicine, *** Department of Biochemistry, ** ** Division of Clinical Epidemiology, Department of Research Development, ***** Division of Medical Genetics, Department of Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand. t This study was supported by grants from the National Research Council of Thailand, 1998-1999 fiscal years.
Objectives : To examine the association between apolipoprotein E genotype (ApoE) and dementia in Thai elderly and patients to examine the alleles frequencies of ApoE in a Thai population.
Materials and Methods : Seventy-eight cases and ninety-four controls from a community based population were recruited. Their ages were all over 50 years. Dementia was diagnosed by DSM IV criteria. Blood was taken and stored for DNA extraction and for restriction enzyme analysis of ApoE genotype. Descriptive analysis and odds ratios from SPSS 9.0 program were used in this study.
Results : Alleles frequencies of ApoE E2, E 3, E4 in normal controls were 0.03, 0.80, 0.17 and alleles frequencies of ApoE E3, E4 in dementia subjects were 0.71 and 0.29, respectively. Odds ratios for dementia risk of apolipoprotein genes were as follows: 0.62 for ApoE E 3 and 1.98 for ApoE E4• In this study, forty-two dementia subjects had Alzheimer's disease. Fifty nine point five per cent of Alzheimer's disease subjects carried ApoE E4 (positive predictive value is 0.60).
Conclusion : Thai elderly carry ApoE genotype distribution similar to that reported in other ethnic groups. Bearing ApoE E4 gene increases the risk of developing dementia. The use of ApoE genotyping can only be a diagnostic adjunct for Alzheimer's disease.
Keywords : Dementia, ApoE Genotype
