The G16319A substitution frequency in a hemorrhagic stroke

BACKGROUND: The aim of this paper is to trace the nucleotide alterations within the D-loop region of the mitochondrial DNA, affecting both the mtDNA ability to replicate and the transcription activity of the coding genes located in the H and L threads, in Caucasian patients with an ischemic and hemorrhagic brain strokes. MATERIALS AND METHODS: The DNA from the peripheral blood of 85 patients with recent sustained ischemic and primary hemorrhagic brain stroke was analysed. The control group consisted of 24 volunteers. The genetic studies were conducted by the PCR method, with the application of the primers for the tRNA-treonine. RESULTS: In the blood samples examined, 3-striatal mtDNA patterns were detected. Pattern-1 is characterised by the C16126T substitution, pattern-2 by the G16319A substitution, and pattern-3 by the C16242T substitution. The frequency of occurrence for the particular mtDNA-1, -2, and -3 patterns, established for the group with an ischemic stroke (77.3, 15.2, and 7.6%), the group with a hemorrhagic stroke (0, 73.7, and 26.3%), and the control group (75, 0, and 25%), differs significantly. DISCUSSION: The exchange of the nucleotides within the D-loop region may affect both the mtDNA replication ability and the transcription activity of the coding genes located in the H and L threads. A hypothesis might be made. The G16319A mutation may result in the formation of lesions within the vascular wall. These lesions have a tendency to form microaneurysms or other defects, which, in turn, will decrease the strength of the vascular wall, making it more susceptible to ruptures. CONCLUSION: The G16319A substitution may be considered a factor that increases the risk of a hemorrhagic brain stroke.