Genetic manipulation could help women with poor ovarian reserve

 

The option of using donor eggs in IVF usually do not make any woman happy. Genectics have always been the issue here and egg donation is usually the last resort for with poor ovarian reserve. However, this might not be of much concerns with the recent scientific trend. A new feat in the area of fertility treatments may rest with five young monkeys in a laboratory outside a town. Each of the five carries genes from three parents instead of two,

because they were conceived using a novel and controversial gene therapy. They seem to be completely ordinary. But researchers are watching them closely to make sure they age normally, can reproduce, and have healthy children.
If the outcome is positive, the three-parent fertilization technique will likely be tried in humans, potentially helping women with certain genetic glitches give birth to healthy children. The same approach might also someday provide older women a chance to extend their fertility by freshening up their eggs with contributions from another woman.

Such genetic manipulation sounds uncomfortably like “playing God” to some critics. But the scientist behind the fuzzy-haired monkeys pushes on, as he always has, in a career spent on the scientific frontier.The iconic drawings of cells show a few ovals with squiggles inside but in truth, a normal, healthy cell might have upward of 1,000 mitochondria, each with its own DNA. These genes are inherited only from mothers. (The vastly bigger nuclear genome, of 20,000 genes, is a relatively even mix from mother and father.)
Serious mutations in these 37 mitochondrial genes doom a fetus; slightly milder mutations can lead to muscle weaknesses, heart problems, and intellectual disabilities. Symptoms can turn up at birth or later in life. It isn’t possible to identify a mitochondrial disease in an embryo, so most women who know they are carriers of mitochondrial mutations decide not to have biological children.
Hoping to offer them a chance to have genetically related children, Mitalipov has pioneered a method dubbed “three-parent embryos.”

Step one: He takes the nucleus out of the egg of the mother-to-be.

Step two: He strips a donor egg of its nucleus.

Step three: He implants the mother’s nucleus into the donor egg. The resulting cell now contains DNA from two women: The mother’s DNA in the nucleus (where the bulk of genetic material resides) and the donor’s DNA in the mitochondria.

The egg is then fertilized in vitro, adding the man’s DNA and if all goes well creating an embryo.
So far, Mitalipov has tried this only on mice and a handful of monkeys. He is eager to try the technique to prevent human disease.



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