What is "mitochondrial replacement" that creates a baby from the gene of "three parents"?
ByLisa Rosario Photography
"Mitochondrial replacementAn experiment that creates a baby from three genes, called so called, is starting to move towards approval in the United States.
One scientist said "American Food and Drug Administration(FDA) has released a report recommending "experiments of" substitution of mitochondria "known as a new medical procedure that may be able to prevent dangerous genetic diseases". Medical experiments with mitochondrial replacement have already been approved in the UK, but there are still many obstacles in the U.S. until they have final approval. In order to reduce this obstacle even a little, scientists published the report.
Mitochondrial replacement is a technique that is deeply related to the technology "genome editing" that freely designs genes to change the characteristics of living organisms, and is said to "there is no genome editing without mitochondrial replacement".
Among the critics, the movement of experiment approval in the United States is "sending us to a dangerous slope named" genome editing ", sometimes it is dangerous to replace the mitochondria," There are some people who comment as "Organ transplantation that can not be seen with the naked eye".
MitochondriaIs a substance called a "cell organ", the origin of its name fulfills its role in the cell as a human organ. For example, like a small stomach, it decomposes molecules to carry the whole body energy. Mitochondria is also a substance containing mitochondrial DNA (mtDNA) which is unique DNA different from cell nucleus. Some biologists explain why mitochondria have mtDNA, mitochondria originally a different cell, and in the early stages of cell evolution it is absorbed by other cells in a process called "internal symbiosis" I thought that it remained inside the cell.
Since all the mitochondria of the fertilized egg are derived from the oocyte, the baby inherits the mitochondria from the mother. And the mother mutation of mtDNA is inherited to the child in the same way. Mutation of this mtDNA causes various diseases, so genetic diseases are inherited throughout the relatives. Mutation of mtDNA occurs with a probability of 1/5000, and genetic diseases caused by them vary from heart failure to dementia. There is currently no known method for treating genetic diseases caused by this mtDNA mutation.
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"Mitochondrial replacement" is a treatment that replaces such mutated or damaged mitochondria with a healthy one provided by donors. It is mtDNA to replace it, it will produce eggs using mtDNA from donor and mother's nuclear DNA. By using mitochondria obtained from a healthy donor, if an egg that does not inherit mtDNA that causes genetic diseases is completed and this is fertilized, "a child with three parents genetically" will be born .
Mr. Nita Farahani of the bioethics scholar said that the proportion of DNA occupied by mitochondria is very small, so "a child with three parents genetically" is a slightly leaping expression, comments. It is said that "a baby whose cell organ has been transplanted" is a better expression than it.
The FDA received reports, gathered many experts from the American Academy of Sciences etc and is currently deliberating the pros and cons for mitochondrial replacement clinical trials approval. The mitochondrial replacement has already cleared the animal experiment, and it seems that many intellectuals think "ethically safe".
◆ 2016/09/28 added
It became clear that American researchers were the first in the world to have "babies with three DNAs" birthed.
First 'three person baby' born using new method - BBC News
Dr. John Zhang of the New Hope Infertility Treatment Center, et al. Extracted the nucleus from the mother's egg to allow a Jordanian woman with a genetic disorder and experienced abortion four times to give a healthy baby, By successfully transplanting it, we succeeded in creating "a baby with three people of DNA". In this case, which took place as part of infertility treatment, it was said that it was held in Mexico, not regulated America. A baby with three DNAs was born for the first time using the replacement method of mitochondrial DNA, but there are opinions that are concerned about safety due to research that is unknown, and who is to be a parent of a child Voices worried about the lack of social system are raised.