A study on the association between cystatin C gene polymorphism and late-onset Alzheimer's disease in a population of Iranian patients

Alzheimer's disease (AD) is the most common age-associated neurodegenerative disease with involvement of genetic factors. Recent studies have shown that the protein cystatin C binds soluble Aβ and inhibits Aβ oligomerization and amyloidogenesis, protecting the brain against amyloid-induced toxicity. Moreover, a decreased cystatin C secretion is associated with a polymorphism found in the cystatin C gene. In this study the association between rs1064039 polymorphism and late-onset AD was investigated.

We conducted a case-control study including a clinically well-defined group of 160 late-onset AD patients and 167 age-matched controls. The polymorphism was determined by polymerase chain reaction-restriction fragment length polymorphisms (PCR-PFLP) assay. The allele frequency was analyzed by Chi-square test.

In the group of patients, the frequency of G/G homozygotes was lower, and the frequency of G/A genotype was higher than the corresponding control group (p <0.05).

The results obtained from our study demonstrate an association between rs1064039 polymorphism in CST3 gene and late-onset AD in an Iranian population. Given the minimal significance level of the G/A genotype, this polymorphism seems to have minor effects on the progression of Alzheimer's disease or possibly interfere with other risk factors.
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