The Role of the Rare Variants in the Genes Encoding the Alpha-Ketoglutarate Dehydrogenase in Alzheimer's Disease

• Published in: Life (Basel, Switzerland) Vol. 11; no. 4; p. 321
• Main Authors: Csaban, Dora, Pentelenyi, Klara, Toth-Bencsik, Renata, Illes, Anett, Grosz, Zoltan, Gezsi, Andras, Molnar, Maria Judit
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 06.04.2021; MDPI
• Subjects: Abnormalities; Acidosis; alpha-ketoglutarate dehydrogenase complex; Alzheimer; Alzheimer's disease; Brain research; Cell cycle; Dehydrogenase; Dehydrogenases; Dementia; DLD; Enzymes; Genes; Genetics; Glucose; Health risk assessment; Ketoglutaric acid; Krebs cycle; Medical research; Metabolism; Mitochondria; Mutation; Neurodegeneration; Neurodegenerative diseases; Oxoglutarate dehydrogenase (lipoamide); Pathology; Phosphorylation; rare variants; Reactive oxygen species; Risk analysis; Risk factors; Tricarboxylic acid cycle; Vitamin B; αKGDHc; Germany; rare variants; αKGDHc; brain tissue; dementia; alpha-ketoglutarate dehydrogenase complex; Alzheimer; DLD
• ISSN: 2075-1729; 2075-1729
• DOI: 10.3390/life11040321

There is increasing evidence that several mitochondrial abnormalities are present in the brains of patients with Alzheimer's disease (AD). Decreased alpha-ketoglutarate dehydrogenase complex (αKGDHc) activity was identified in some patients with AD. The αKGDHc is a key enzyme in the Krebs cycle. This enzyme is very sensitive to the harmful effect of reactive oxygen species, which gives them a critical role in the Alzheimer and mitochondrial disease research area. Previously, several genetic risk factors were described in association with AD. Our aim was to analyze the associations of rare damaging variants in the genes encoding αKGDHc subunits and AD. The three genes ( , , ) encoding αKGDHc subunits were sequenced from different brain regions of 11 patients with histologically confirmed AD and the blood of further 35 AD patients. As a control group, we screened 134 persons with whole-exome sequencing. In all subunits, a one-one rare variant was identified with unknown significance based on American College of Medical Genetics and Genomics (ACMG) classification. Based on the literature research and our experience, R263H mutation in the gene seems likely to be pathogenic. In the different cerebral areas, the αKGDHc mutational profile was the same, indicating the presence of germline variants. We hypothesize that the heterozygous missense R263H in the gene may have a role in AD as a mild genetic risk factor.