Figure 6.
One published example of a germline lethal mtDNA mutation. A woman harboring a heteroplasmic mtDNA tRNAThr A15923G mutation lost five pregnancies in a row (triangles). The two surviving term infants died within 2 to 3 d. Postmortem mitochondrial analysis of one infant's skeletal muscle revealed that complex II + III and complex IV activities reduced to 6% and 5% of control and liver complex IV activity that was reduced 37% and complex II + III activity that was undetectable. The mother's twin sister had a similar reproductive history, yet both women were seemingly normal. (From Yoon et al. 1993; modified, with permission, from the authors.)