Association between neurotrophin-3 polymorphisms and executive function in Japanese patients with amnestic mild cognitive impairment and mild Alzheimer disease.

BACKGROUND

We investigated whether neurotrophin (NT)-3 polymorphisms influenced the executive function of patients with 2 separate disease stages with similar dementia conditions: amnestic mild cognitive impairment (A-MCI) or mild Alzheimer disease (AD).

METHODS

Among 215 outpatients with dementia and MCI, 155 with mild AD (n = 108) or A-MCI (n = 47) were recruited and divided into three genotypic groups based on the representative NT-3 functional polymorphisms rs6332 and rs6489630. Next, we compared the frontal assessment battery (FAB) total and subtest scores between the three genotypic groups.

RESULTS

The total FAB score was not significantly associated with the rs6332 and rs6489630 genotypes; however, the conflicting instructions score among the 6 subtests was significantly associated with the rs6332 genotype (p < 0.05). Moreover, in patients with mild AD, the conflicting instructions score differed significantly among the three genotypic groups of rs6332 (p < 0.05) (G/G < A/A: p = 0.042 and G/A < A/A: p = 0.041). No significant differences in any other demographic variables were observed among the three genotypes of rs6332 and rs6489630.

CONCLUSION

These results suggested that an NT-3 polymorphism, rs6332, may significantly influence executive function, reflecting interference performances among patients with mild-stage AD.