Investigation of Aneusomy of Chromosome 21 in the Micronuclei of 13 Patients with Early Onset Alzheimer’s Disease Using Fluorescence in Situ Hybridization: A Pilot Study

Background: Alzheimer’s disease is one of the most common neurodegenerative and dementia disorders in people between the ages of 30 and 65. When symptoms appear in this age group, the disease is referred to as early-onset Alzheimer’s disease (EOAD). Unfortunately, the symptoms are progressive and no current treatments are effective. Methods: In this research, 13 patients, aged 37 to 65 years with symptoms of early-onset Alzheimer’s disease, were studied. First, patient lymphocytes were isolated and cultured in RPMI 1640 medium using a special micronucleus (MN) culture method. Next, the lymphocytes were harvested and prepared on slides. The slides were then examined by fluorescent microscopy using a unique FISH protocol specific for MNs. The patients were divided into groups aged 30-39, 40-49, and 50-65. Results: We found that 19.76% of the MNs from our EOAD patients originated in chromosome 21. Micronuclei originated in chromosome 21 in 21.20 and 16.52% of patients without and with family histories of Alzheimer’s, respectively. This difference was not significant. Also, the percentage of micronuclei originating in chromosome 21 was not dependent on the patient age at the time of the study, or symptom onset age or duration. Conclusions: This study shows that the rate of micronuclei with the origin of chromosome 21 is high in these patients. However, the micronucleus increased has no significant relationship with age and duration of disease or family history of it.

Keywords:

Early-onset Alzheimer’s disease (EOAD) , Chromosomal instability , Fluorescence in Situ Hybridization (FISH) , Neurodegenerative diseases , Micronucleus (MN).