Affiliations: [a] Genética Molecular, Hospital Universitario Central de Asturias, Oviedo, Spain | [b] Instituto de Investigación Nefrológica, Hospital Universitario Central de Asturias, Oviedo, Spain
Correspondence:
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Corresping author: Dr. Eliecer Coto, Genética Molecular. Hospital Universitario Central de Asturias 33006. Oviedo. Spain. Tel./Fax: +34 985 27 36 57; E-mail: eliecer.coto@sespa.princast.es.
Abstract: Impaired mitochondrial function and an increased number of mutations in mitochondrial DNA (mtDNA) has been found in brains of patients with late-onset Alzheimer's disease (LOAD). The TFAM-gene encodes the mitochondrial transcription factor A, a protein that controls the transcription, replication, damage sensing, and repair of mtDNA. TFAM is on human chromosome region 10q21.1, where a locus for LOAD has been mapped. Our objective was to determine the role of TFAM-gene variation in the risk of LOAD. The seven TFAM coding exons were analysed through single strand conformation analysis and direct sequencing in a cohort of Spanish LOAD-patients and healthy controls. We found four common polymorphisms, two in the flanquing intronic and two in the coding sequences. Polymorphism rs1937 (+35 G/C) was the only missense change (S12T). Genotyping of this polymorphism in 300 LOAD-patients and 183 healthy controls showed a significantly higher frequency of GG-homozygotes in the patients (92% vs. 86%; p=0.04; OR=1.91, 95%CI=1.02–3.50). This suggests that S12 is a risk factor for LOAD in our population. In conclusion, rare variants (mutations) in the TFAM gene were not found in LOAD-patients, but the S12T polymorphism was a moderate risk factor for LOAD in our population.
