Summary
A technique to prevent transmission of mitochondrial disease by transferring nuclear DNA into a donor egg.
In depth
Maternal spindle transfer or pronuclear transfer moves the nuclear genome into a donor egg with healthy mitochondria. Approved in the UK in 2015; the first children were reported in 2023. Residual mutant mitochondria may cause reversion.
It aims to prevent transmission of mutant mtDNA, as in Leigh syndrome. Offspring carry DNA from three people, but the donor contributes under 1 percent. Ethics and safety are debated.
Remember: mitochondrial genes encode only 13 proteins; most mitochondrial proteins are nuclear.
Mitochondria carry their own DNA, inherited only from the mother, and mutations cause serious diseases affecting energy-hungry organs. Mitochondrial replacement therapy (MRT) aims to prevent transmission by combining a mother's nuclear DNA with healthy donor mitochondria.
In maternal spindle transfer, the spindle with chromosomes is moved from the patient's egg to an enucleated donor egg; in pronuclear transfer, nuclei of a fertilised egg are moved into a donor zygote. Babies have DNA from three people, though donor contribution is tiny (about 0.1 percent). The UK legalised it in 2015, and the first births were reported in 2023.
Frequently asked questions
What is Mitochondrial Replacement Therapy?
A technique to prevent transmission of mitochondrial disease by transferring nuclear DNA into a donor egg.
Which area of biology covers Mitochondrial Replacement Therapy, and how advanced is it?
Mitochondrial Replacement Therapy is one of the 56 topics in Biotechnology & Genomics. It is rated Advanced, so it suits learners who want specialist depth. Related topics in this area include Gene Therapy, Gene Therapy Vectors, Gene Drives.
Why does Mitochondrial Replacement Therapy matter?
It is germline modification, so debates include safety and carry-over of mutant mitochondria.
Can you give an example of Mitochondrial Replacement Therapy?
It is sometimes called three-parent IVF.
What should I learn before Mitochondrial Replacement Therapy?
Work through the Beginner topics in Biotechnology & Genomics first, such as Biotechnology, Genetic Engineering, Selective Breeding, then return to Mitochondrial Replacement Therapy. Advanced topics assume the Intermediate vocabulary.
What topics are related to Mitochondrial Replacement Therapy?
The closest topics to Mitochondrial Replacement Therapy are Gene Therapy, Gene Therapy Vectors, Gene Drives, Transgenic Organisms. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Mitochondrial Replacement Therapy?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Mitochondrial Replacement Therapy. To practise the whole of Biotechnology & Genomics, use the Biotechnology & Genomics quiz.
How is Mitochondrial Replacement Therapy different from Gene Therapy?
Mitochondrial Replacement Therapy: A technique to prevent transmission of mitochondrial disease by transferring nuclear DNA into a donor egg. Gene Therapy: Treating disease by introducing, repairing or replacing faulty genes in a patient's cells. Read both side by side and note what each one explains.
How should I study Mitochondrial Replacement Therapy step by step?
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Gene Therapy and explain the difference aloud. Finally, take the Biotechnology & Genomics quiz and come back to this page for any question you miss.