DNA mutations in mitochondrial (mt) genes.

It is known for several years now that mitochondrial DNA (mtDNA) defects can cause serious diseases. Several point mutations dispersed throughout the mt genome and disturbing the proper formation and function of the mtDNA gene products have already been identified.
We have focused our attention on the study of the mt ATPase subunit 6 gene in patients suspected of mitochondrial encephalomyopathies. Analysis of the gene by PCR-SSCP techniques have already revealed several unreported DNA mutations. Often these sequence variants are natural polymorphisms as mtDNA is very polymorphic. However, DNA alterations in the ATPase gene of two patients with different clinical presentations, but suggestive for mitochondrial energy deficiency, were found. It was shown that the mtDNA mutations underlie the disturbance of the mt respiratory function in these patients. Therefore we recommend a meticulous study of the mt ATPase gene in patients suspected of mt DNA diseases. To avoid misinterpretation of natural polymorphisms observed by PCR-SSCP mobility shifts we are also screening normal, un related control persons.