Case Study Of Two Current Embryo Selection Methods

Preimplantation genetic diagnosis (PGD) is a form of genetic testing. It is similar to the screening of abnormal chromosome count only used to test for genetic diseases. The fertility institutes have used this to take gender selection to the next level. Stating that this has a greater than 99,9% success rate.

In the United Kingdom alone, 150 new born children per year suffer from life threatening, mitochondrial diseases. These diseases vary in severity from person to person, making them difficult to diagnose, and they inflict an array of ailments such as neurological problems, muscle weakness, visual or auditory impairments, heart, liver, and kidney disease,

Therapeutic genetic manipulation is preformed by doctors to prevent diseases that the baby is carrying. The baby is tested by screening the embryo for any possible unknown diseases. Sometimes the PGD or preimplantation genetic diagnosis technique is used for this ("Biotechnology special focus"). The main diseases PGD is used to test for in babies are Hunntington's disease, Tay-sacks, Alzheimers, Familia cancers, Sickle Cell disease, Hemophilia, Neurofibromatosis, Fanconi's Anemia, Cystic fibrosis and most recently, Down's Syndrome ("Hooray for designer babies", 2002). This technique involves removing the unfertilized egg from the female, mating it with a sperm and then testing it for diseases. If all the diseases are absent, the fertilized egg is planted into the mother's uterus to develop into a baby. Some other unpredictable diseases may also be carried in the baby's chromosomes. Chromosome carrying diseases and disorders include: miscarriage of the baby, physical birth defects or down syndrome (Biotechnology special focus").

United States genetic centers now offer DNA tests for over 30 or 40 of the more commonly inherited disorders. Those including cystic fibrosis, susceptibility to breast cancer, X syndrome, Huntington’s disease, Duchenne muscular dystrophy, and many other various disorders (Golden). Also, with recent developments, couples are able to have a pre-implantation genetic diagnosis (PGD). This procedure allows the testing of genetic disorders before germination. It consists of “petri-dish” testing of sperm and egg cells donated by the soon to be parents. This procedure prevents the idea of abortion, for if genetic problems occur, you are not destroying a fetus, but simple flushing away embryo cells.

One advantage is the ability to reduce the risk for diseases. Through procedures like pre-implantation genetic diagnosis (PGD), one can inspect embryos created by in vitro fertilization (IVF) for many genetic conditions (Macklin, 2014, para. 1). While this process can be extremely beneficial ensuring the health of future generations, it can be misused in many ways.

Mitochondrial disorders may be caused by mutations which are acquired or inherited in mitochondrial DNA (mtDNA) or in nuclear genes that code for mitochondria. Disorders can also be a result of environmental stress, adverse

The article Replacing the cell’s power plants by Eric A. Shoubridge discusses the DNA found within mitochondria. Mitochondrial DNA (mtDNA) differs from nuclear DNA as it is inherited from only the mother. However, the mtDNA can also contain mutations which, similar to the nuclear DNA, have the potential to cause severe complications. Due to the mtDNA being restricted to the mitochondria multiple approaches have been developed in effort to reduce or prevent the amount and effect of mtDNA mutations.

With new technology scientists have come up with a way to insert mitochondrial DNA of a healthy egg to one that is genetically damaged or impaired. “Scientists have also recently reported a method of extracting defective mitochondria, the energy powerhouses of cells, from a woman 's egg and replacing them with healthy mitochondria from a donor egg” (Ghose 2014). In 2015 there was the first reports of mitochondrial DNA transplant, “Three-parent babies” is a sensationalized term to describe a special form of in vitro fertilization, or I.V.F., that is better labeled mitochondrial transfer” (Malik 2015). This process is similar to in vitro fertilization where the child is created in the test tube, but is then fertilized egg injected with the healthy mitochondrial DNA (Malik 2015). The mitochondrial DNA is injected into the nucleus where the hope is that the healthy mitochondrial DNA will take over the unhealthy mitochondrial DNA (Malik 2015). This advancement in this process and medical technology is a large step for the medical field. Is this step for better or worse for the human population.

Mitochondrial disease is the malfunctioning of the mitochondria organelle located in every cell of the human body except the red blood cells. These organelles are responsible for the synthesis of 90% of the ATP energy required for a normal bodily function. Consequently if a patient is diagnosed with mtDNA disease, their individual cells will generate less energy than required resulting

Today, there are many different kinds of mitochondrial DNA mutations. These mutations can vary in severity, and the consequences that result from the mutation. But how did these mutations arise? And how do they affect those afflicted with the mutation? In order to properly understand human mitochondrial DNA mutations, we must begin with the early stages of human life.

A team of researchers from Boston University, supervised by Thomas Tien, studied the mitochondrial function

Mitochondria are the powerhouses of every cell in our bodies. According to the United Mitochondrial Disease Foundation, the mitochondrial produce most of the energy for the body (United Mitochondrial Disease Foundation). When this process is interrupted or does not take place then cellular damage begins to occur (United Mitochondrial Disease Foundation). Rolf Luft, Lars Ernster, and Bjorn Afzelius are credited with the first diagnosis of mitochondrial disease via muscle biopsy in 1962 (DiMauro, 2011). Succinctly, it is a “defect in the respiratory chain (DiMauro, 2011)”. Since mitochondria are in every cell in the body, and cells are specialized to the organ system to which they belong, the disease will manifest different symptoms in different individuals based on the organ system(s) affected (United Mitochondrial Disease Foundation). Symptoms can be present from every organ system, however, depending upon the actual genetic encoding affecting the mitochondrial can determine which disease classification a patient may fall within (DiMauro, 2011), (United Mitochondrial Disease Foundation).

October 2001 - Fertility experts announce they will begin to offer PGD for use in sex selection to clients

Canine Transmissible Venereal Tumor, or otherwise known as CTVT, is the oldest known Cancer to exist, having started about 11,000 thousand years ago with a husky-like dog. Scientists know this because when a person has cancer the cells die with the person and this is not true with CTVT. The Cancer cells from the original dog are still around today, these cells transferred to another dog during mating and have spread further from there. The Cambridge Research team of transmissible cancer has said that sometimes the mitochondrial DNA is swapped and create a “genetic flag” that has helped the researchers know how the cancer has spread. There are five varieties of mitochondrial DNA or “clades” today. The clades also help to learn the differences between each

In the United States, an estimated 2.3 million couples are considered infertile [Wekesser, 1996]. This creates a large need for infertility specialists and clinics specializing in fertility treatments. With the quickly advancing field of rep roductive services and the quest for creating better, healthier babies, a new service called Preimplantation Genetic Diagnosis (PGD) is being offered in conjunction with In vitro fertilization.