Genetische Polymorphismen der mtDNA als Risikofaktoren für das SIDS (Sudden Infant Death Syndrome)

Abstract

Sudden Infant Death Syndrome (SIDS) is the most frequent cause of death in infants within the first year of life. The underlying pathophysiological changes and the exact cause of death are up to now unknown. Many fields of research are investigating this phenomenon, concentrating on genetics and different polymorphisms. Particularly the genetic polymorphisms of mitochondrial DNA (mtDNA) are in the focus of investigation. For this work, three polymorphisms of mtDNA and possible risk factors for SIDS were analysed. A mitochondrial polymorphism can result in a hindered gene expression of the subunits of the respiratory chain. This may cause a deficit in ATP (adenosine triphosphate) production. This deficit hinders the normal functioning of the physiological processes in a human cell. Within the framework of this thesis, the SNPs G3010A, T16519C and C7028T of the mtDNA were investigated with respect to a possible association with SIDS. Already in 2003, Divne et al. (2003) investigated the SNPs G3010A and C7028T with respect to SIDS, however without any significant results. Boles et al. (2010) could establish an association between the polymorphisms G3010A and T16519C and SIDS. Since there is to date no comprehensive publication on this case, the role of the polymorphisms G3010A and T16519C, and the most frequent variation (in Europeans) C7028T in SIDS was investigated in this work. The DNA of 176 cases of SIDS and a control panel of 113 adults was investigated using singleplex PCR and RFLP analysis. Based on the genotyping, the SNPs could be quantified and analysed with respect to a possible difference between the SIDS cases and the control panel. In the observation of the single SNPs, G3010A, T16519C and C7028T, no significant differences between the of SIDS cases and the control panel were found. The increased occurence of increased mutation rates in individuals with SIDS in comparison with the control panel, as well as the hypothesis made by Opdal et al. (1999) that the presence of a mutation in the D-Loop region indicates the occurrence of further mutations in the encoding area could be confirmed with this work.