Novel mitochondrial DNA variant that may give a false positive diagnosis for the T8993c mutation

Abstract

Background: Two of the most common mutations in the mitochondrial DNA (mtDNA) of children occur at nucleotide 8993 (nt8993). The base substitutions oft to G (T8993G) and T to C (T8993C) are known to cause neurologic disorders and are routinely screened for in patients suspected of having a mitochondrial disorder. Methods and Results: Both mutations at nt8993 create a novel HpaII restriction endonuclease site and are usually detected by polymerase chain reaction (PCR) amplification of a section of the mtDNA containing nt8993, followed by HpaII digestion. The resulting fragment sizes are then analyzed by agarose gel electrophoresis. Initial testing on a child referred for analysis suggested th..