Dinucleotide repeat polymorphism in interferon-gamma gene is not associated with sporadic Alzheimer's disease.

Various factors have been suggested to participate in Alzheimer's disease (AD) pathology, and some inflammatory cytokines may play an important role in the development of AD. Interferon-gamma (IFNG), an important pro-inflammatory cytokine, is encoded by a single gene mapped to chromosome 12, one of the candidate locus of AD. The first intron in the IFNG gene represents a CA repeat polymorphism that is possible to affect the IFNG secretion dose. We speculate that the polymorphism may have some roles on the inflammatory process and the pathologic change in AD, so we analyzed the IFNG gene polymorphism in 199 Japanese AD patients and 225 Japanese controls. There were no significant differences in allele frequency between the AD and control groups. We conclude that IFNG gene polymorphism is not associated with development of AD.