Clinical features of dementia associated with apolipoprotein ε4: discrimination with a neural network genetic algorithm.

Background It is unclear whether the APOE ε4 allele is associated with distinct clinical features in dementia. Method 100 cases meeting ICD criteria for dementia were interviewed using standardized instruments and genotyped for APOE. The presence of the ε4 allele was used by a genetic algorithm neural network (GANN) to discriminate symptoms and signs. Results The GANN selected six features: gender, systolic blood pressure, absence of ankle tendon reflexes, history of weight loss, history of falls, and interviewer observed lability of mood. Using these features, a neural network discriminated cases according to ε4 highly accurately (area under receiver operating characteristic=0.83, sensitivity=0.78, specificity=0.78). Conclusions A GANN is able to discriminate a clinically distinct group of features among dementia patients who express the ε4 allele. Copyright © 2001 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]