Mitochondrial DNA depletion presenting prenatally with skin edema and multisystem disease immediately after birth

We describe two newborn sisters who presented in the third trimester with diminished fetal movements and skin edema, but with no other signs of hydrops fetalis. Within hours of birth, both developed profound lactic acidemia, followed by multi-organ failure. In muscle mitochondria, the activity of all enzymatic complexes that contain mitochondrial DNA (mtDNA)-encoded subunits was markedly decreased. Southern blot analysis revealed a profound reduction in the mtDNA/nuclear DNA ratio, implying mtDNA depletion. The prenatal identification of skin edema in two patients with mtDNA depletion, and its absence in a healthy sibling, suggest that skin edema should be regarded as a novel manifestation of mtDNA depletion. This finding shows that mtDNA depletion can present prenatally and, consequently, may aid the clinician in making a diagnosis, prenatally, of this genetic defect.