Apolipoprotein E polymorphism in German patients with frontotemporal degeneration

Objectives: The apolipoprotein E (apoE) polymorphism, designated as ε2, ε3, ε4, is a genetic risk factor associated with several forms of dementia. Inconclusive results have been reported in patients with frontotemporal degeneration which prompted this study of the apoE polymorphism in a German sample with frontotemporal degeneration. Methods: The frequencies of the ε2 and ε4 alleles and the effect of these alleles on the age at onset in 52 patients with frontotemporal degeneration who underwent a thorough diagnostic examination and in 182 cognitively healthy age matched controls were assessed. Genotype comparisons between the groups were performed using multiple logistic regression analysis. Ages at onset according to the apoE genotype were compared by linear regression analysis. Results: In patients with frontotemporal degeneration apoE ε2 and ε4 allele frequencies were 9.6% each, whereas the corresponding frequencies in controls were 9.6% and 9.9%, respectively. There was no significant difference in either ε2 or ε4 allele frequency between the groups. Age at onset was highest in patients with the ε2/ε3 genotype (61.3 years) followed by patients with the ε3/ε3 (58.3 years) and was lowest in patients with the ε3/ε4 genotype (56.4 years) but the differences failed to reach statistical significance. Conclusion: Allelic variants of the apoE gene do not modulate occurrence or age at onset in this sample of German patients with frontotemporal degeneration.