Mitochondrial DNA heteroplasmy after human ooplasmic transplantation

Objective: To determine the patterns of mitochondrial inheritance in embryos, fetuses, and infants after ooplasmic transplantation using the technique of mitochondrial DNA (mtDNA) fingerprinting. Design: Prospective clinical study. Setting: The IVF program at Saint Barnabas Medical Center, a nonprofit community hospital. Patient(s): In a total of 23 cases with recurrent implantation failure after IVF ooplasmic transplantation was performed. Thirteen embryos from two patients and amniotic cells from four patients were investigated for heteroplasmy. Placenta and fetal cord blood cells from four newborn babies/infants were also investigated. Intervention(s): None. Main Outcome Measure(s): mtDNA fingerprinting, polymerase chain reaction, and DNA sequencing analysis. Result(s): In addition to the recipient maternal mitochondrial DNA, a small proportion of donor mitochondrial DNA was detected in samples with the following frequencies: embryos (n = 6/13), amniocytes (n = 1/4), placenta (n = 2/4), and fetal cord blood (n = 2/4). Fingerprinting showed that nuclear DNA was not inherited from the donor in placenta or fetal cord blood of the babies. Conclusion(s): Ooplasmic transfer can result in sustained mtDNA heteroplasmy representing both donor and recipient. This was shown by mtDNA fingerprinting of embryos, amniocytes, fetal placenta, and cord blood. These results show that the donor-derived mitochondrial population persists after ooplasmic transfer and may be replicated during fetal development.