Clinical features of dementia associated with apolipoprotein epsilon4: discrimination with a neural network genetic algorithm.

BACKGROUND: It is unclear whether the APOE epsilon4 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 epsilon4 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 epsilon4 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 epsilon4 allele. Copyright 2001 John Wiley & Sons, Ltd.