An infant in Ireland was born in April of 2015. She was healthy despite the fact that both of her parents carried a gene that leads to a genetically inherited condition. This was made possible due to a combination of successful PGD and karyomapping.
John and Emma O’Connor each carry a gene that leads to a mucolipidosis. It is a metabolic disorder that has been described as “a life limiting condition”. It was considered to be very likely that these two parents would have a child who had that genetically inherited condition.
Mucolipidoses is a group of inherited metabolic diseases that affect the body’s ability to carry out the normal turnover of various materials within cells. Abnormal amounts of carbohydrates and fatty materials (also called lipids) accumulate in cells.
The cells cannot handle that amount and this results in damage to the cell. The damage causes symptoms that can range from mild learning disabilities, to severe intellectual impairment, to skeletal deformities. Early symptoms include vision problems and developmental delays. In many cases, children die from mucolipidoses.
In order to help the O’Connor’s have a healthy baby, two techniques were used. The first was PGD, which stands for pre-implantation genetic diagnosis. First, a woman must undergo in vitro fertilization (IVF) and have her eggs fertilized. Embryos are grown in a laboratory. An embryologist removes one or two of the cells from each embryo and tests the cells for a gene that causes a specific genetic condition.
Karyomapping is a comprehensive means of simultaneous monogenic and cytogenetic PGD. Researchers found that karyomapping can be used to detect a wide range of genetic diseases in IVF embryos. Karyomapping can be used to check for several different genetic disorders at the same time. An embryo that was found not to have those genes is then transferred to the womb.
The combination of PGD and karyomapping has now been successfully used to help parents who carry the genes that lead to mucolipidosis to have a healthy child. That is how the O’Connor’s had a healthy baby girl that they named Megan.
Previous to this, another Irish couple used PGD to have a baby who was born free of cystic fibrosis. There was also a case where karyomapping was used for a couple in which the male partner was affected with Marfan syndrome (which is an autosomal dominant disease affecting the connective tissue).
Single cells from IVF embryos were tested via PGD in order to determine which embryos were free of the genes that lead to Marfan syndrome. Karyomapping was used to confirm that specific embryos lacked those genes. This resulted in a healthy baby.
Image by Kristen Burns on Flickr.
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