Olfactory identification and apolipoprotein E epsilon 4 allele in mild cognitive impairment.
To investigate olfactory identification and apolipoprotein E epsilon 4 allele in patients with mild cognitive impairment (MCI), we used Cross-Cultural Smell Identification Test (CC-SIT) from University of Pennsylvania to assess olfactory identification performance and polymerase chain reaction (PCR) to detect apolipoprotein E epsilon 4 (ApoE epsilon 4) allele in 28 patients with MCI and the 30 age-matched control subjects in present study. The Mann-Whitney U test demonstrated that the MCI group performed significantly worse on CC-SIT than the normal aging group (P<0.01). For MCI patients olfaction scores correlated positively with CAMCOG-C (r=0.61, P<0.01), but not with age, gender or years of education. In normal subjects, the CC-SIT score showed no significant associations with age, gender, years of education, or CAMCOG-C. As the least common allele in Chinese, epsilon 4 was found in 13.3% of controls and in 35.8% of MCI in this study. ApoE epsilon 4 was significantly higher in MCI group than normal group (chi(2)=4.65, P<0.01). There was a significant effect of allele status on odor identification: subjects with epsilon 4 allele were not able to identify as many odors as the subjects without epsilon 4 allele (P<0.01). These results suggested that the decreased olfactory identification in MCI may be a marker for the early diagnosis of Alzheimer's disease, and ApoE genotype may be part of the basis of olfactory identification decline.
Wang
Qing-Song
QS
Laboratory of Neurodegenerative Diseases, School of Life Science, University of Science and Technology of China, 230027, Hefei, PR China.
Tian
Lin
L
Huang
Yong-Lu
YL
Qin
Song
S
He
Long-Quan
LQ
Zhou
Jiang-Ning
JN
D000367:Age Factors; D000368:Aged; D000544:Alzheimer Disease / Q000175:diagnosis / Q000235:genetics* / Q000378:metabolism; D053327:Apolipoprotein E4; D001057:Apolipoproteins E / Q000235:genetics* / Q000378:metabolism; D002681:China / Q000208:ethnology; D003072:Cognition Disorders / Q000235:genetics* / Q000378:metabolism / Q000503:physiopathology; D004252:DNA Mutational Analysis; D005260:Female; D005787:Gene Frequency; D005819:Genetic Markers / Q000235:genetics; D020022:Genetic Predisposition to Disease / Q000235:genetics; D005820:Genetic Testing; D006801:Humans; D008297:Male; D000857:Olfaction Disorders / Q000150:complications / Q000235:genetics* / Q000378:metabolism; D012737:Sex Factors; D012903:Smell / Q000235:genetics*
D053327:Apolipoprotein E4; D001057:Apolipoproteins E; D005819:Genetic Markers