%0 Journal Article %T Japanese Alzheimer¡¯s Disease and Other Complex Disorders Diagnosis Based on Mitochondrial SNP Haplogroups %A Shigeru Takasaki %J International Journal of Alzheimer's Disease %D 2012 %I Hindawi Publishing Corporation %R 10.1155/2012/245038 %X This paper first explains how the relations between Japanese Alzheimer¡¯s disease (AD) patients and their mitochondrial SNP frequencies at individual mtDNA positions examined using the radial basis function (RBF) network and a method based on RBF network predictions and that Japanese AD patients are associated with the haplogroups G2a and N9b1. It then describes a method for the initial diagnosis of Alzheimer¡¯s disease that is based on the mtSNP haplogroups of the AD patients. The method examines the relations between someone¡¯s mtDNA mutations and the mtSNPs of AD patients. As the mtSNP haplogroups thus obtained indicate which nucleotides of mtDNA loci are changed in the Alzheimer¡¯s patients, a person¡¯s probability of becoming an AD patient can be predicted by comparing those mtDNA mutations with that person¡¯s mtDNA mutations. The proposed method can also be used to diagnose diseases such as Parkinson¡¯s disease and type 2 diabetes and to identify people likely to become centenarians. 1. Introduction Mitochondria are essential cytoplasmic organelles generating cellular energy in the form of adenosine triphosphate by oxidative phosphorylation. Because most cells contain hundreds of mitochondria, each having multiple copies of their mitochondrial DNA (mtDNA), each cell contains several thousand mtDNA copies. The mutation rate for mtDNA is very high, and when mtDNA mutations occur, the cells contain a mixture of wild-type and mutant mtDNAs. As the mutations accumulate, the percentage of mutant mtDNAs increases and the amount of energy produced within the cell can decline until it falls below the level necessary for the cell to function normally. When this bioenergetic threshold is crossed, disease symptoms appear and become progressively worse. Mitochondrial diseases encompass an extraordinary assemblage of clinical problems, usually involving tissues that require large amounts of energy, such as those in the heart, skeletal muscle, kidney, and endocrine glands [1¨C3]. Although there are reports that mtDNA mutations are related to aging and a wide variety of diseases¡ªsuch as Alzheimer¡¯s disease (AD), Parkinson¡¯s disease (PD), type 2 diabetes (T2D) disease, and various kinds of cancer [4¨C20]¡ªthose reports focus on the amino acid replacements caused by mtDNA mutations. Mitochondrial functions can of course be affected directly by amino acid replacements, but they can also be affected indirectly by mutations in mtDNA control regions. It is, therefore, important to examine the relations between all mtDNA mutations and disease patients or centenarians. In the work %U http://www.hindawi.com/journals/ijad/2012/245038/