Tumor necrosis factor-a −308 G/A polymorphism in a sample of Egyptian patients with Alzheimer′s disease

Abstract

Objective This study was designed to determine whether tumor necrosis factor-a ( TNF-a) −308 G/A polymorphism was a risk factor for late-onset Alzheimer's disease (LOAD) and/or was associated with a more severe form of LOAD in a sample of Egyptian patients. Background LOAD is a neurodegenerative disorder and the most common form of dementia affecting people over 65 years of age. Polymorphisms in the promoter region of the TNF-a gene have been reported to increase the transcription rate of the gene and thus might influence the risk for LOAD. Patients and methods This study enrolled 31 elderly patients diagnosed with probable Alzheimer's disease. The diagnosis was according to the DSM-IV-TR and the National Institute of Neurological and Communicative Disorders and Stroke and Alzheimer's Disease and Related Disorder Association (NINCDS-ADRDA). Thirty-one cognitively normal elderly controls were included and were subjected to the Clinical Dementia Rating Scale, the Activities of Daily Living scale, and the Instrumental Activities of Daily Living scale. Results The presence of the TNF-a −308 A allele was associated with an increased risk for LOAD, younger age of onset of LOAD by about 4 years, and statistically significantly more severe form of LOAD in Egyptian patients. Conclusion The TNF-a −308 A allele was a risk factor for the development of LOAD in Egyptian patients.