|dc.description.abstract||The relevance of haplogroups in mitochondrial disease was investigated in this study.
Twenty-seven paediatric patients with clinically suspected mitochondrial disorders from
diverse ethnic origins were investigated via an automated sequencing strategy. Previous
studies in a similar population identified only the A3243G reported causative mutation in a
single patient, in addition to a number of reported and unreported polymorphisms. It
suggested that the aetiology of mitochondrial disorders in Africa, specifically South Africa,
might be different from that of other continents.
Comparison between these sequences and the Revised Cambridge Reference Sequence
revealed 37 polymorphic sites (7 novel changes, 30 reported alterations). No previously
reported causative mutation was detected. The findings support the hypothesis that the
aetiology of mitochondrial disorders in Africa is unique.
Sixty-three percent of patients in the current study belonged to haplogroup L3 (48% in
L3b), 22% to LO, 11% to L2a, and 4% to M. No patients with an L1 haplogroup were
observed in this study. The above-mentioned observations have important implications.
There was distinct clustering of affected patients in macrohaplogroup L. In this patient
cohort, certain sub-haplogroups may play a susceptibility or protective role with regard to
mitochondrial dysfunction. Results generated in this study suggested that differential
haplogroup-tissue-specific reliance on mitochondrial ATP may culminate in specific