Would you like your son or daughter to have blonde hair? Blue eyes? Imagine being able to choose such a trait for your child. Want a boy or a girl for sure? That scientific technology already exists. It won’t be long before doctors and embryologists are able to single out the genes responsible for hair and eye color or even hair texture, skin tone, or height. Eventually you will be able to design your child.
Assisted Reproductive Technology (ART) is quite commonplace these days. These are procedures to help couples who are unable to have a child for whatever reason, be able to conceive. They include intrauterine inseminations (IUI) and in vitro fertilization (IVF). For IVF specifically, the female patient (or her egg donor) takes injectable drugs that stimulate the ovaries to produce multiple follicles, each of which should contain an egg. After these follicles and eggs reach maturation, she is typically sedated and the eggs are retrieved from the ovaries using a long needle. These eggs are then placed in a dish and the male partner’s sperm or the sperm of a donor male are allowed to fertilize these eggs to create human embryos. Sometimes if there are issues with the sperm the embryologist can isolate a single sperm and actually inject it into the egg, thereby forcing fertilization. The embryos are then allowed to grow in a specialized medium (nutrient rich fluid) and when they reach either three or five days of development, they are transferred back in to the recipient’s uterus, hopefully to attach and then develop into a healthy pregnancy. While this already may seem like science fiction to some, scientists have even taken nature a step further. There are ways to tests these embryos for particular genetic disorders so they can be avoided and thereby not transmitted to a potential child. A process called Preimplantation Genetic Diagnosis (PGD) or Preimplantation Genetic Screening (PGS) is sometimes used to screen embryos for a variety of diseases. These include:
- Cystic Fibrosis
- Hemophilia
- Huntington’s Disease
- Marfan’s Disease
- Muscular Distrophy
- Thalassemia
- Tay Sachs
- Spinal Muscular Atrophy
- Sickle Cell Anemia
- Down’s syndrome (Trisomy 21)
- Edward’s Syndrome (Trisomy 18)
- Trisomy 13
To perform this screening an embryo at the day 3 or day 5 stage is biopsied, meaning one cell is removed and then tested to see if it carries any of these diseases. If it does, the affected embryos are not transferred to the patient.
In some cases, certain diseases are passed only to male (or conversely female) offspring. If this is the case, the andrology department, the technicians who handle the semen preparation, can do a “wash” of the sperm to isolate only female or male sperm. In this case, it means the parents can effectively choose the gender of their child. Typically this is used to avoid transmission of disease or disorder, but, as it is becoming more commonplace, people (sometimes celebrities) are using it just for fun, to be able to get the girl they always wanted after having three boys or conversely to have their boy in a houseful of girls. There are many moral and religious complaints for using ART for these purposes; some believe it to be an unethical practice.
Kari Stefansson, chief executive of deCode, “points out that such a test will only provide a certain level of probability that a child will have blond hair or green eyes, not an absolute guarantee. He says, ‘I vehemently oppose the use of these discoveries for tailor-making children.’ In the long run, he adds, such a practice would “decrease human diversity,” and that’s dangerous.’” William Kearns, a medical geneticist and director of the Shady Grove Center for Preimplantation Genetics in Rockville, Md., says he is getting closer to solving the problem. In a presentation made at a November meeting of the American Society of Human Genetics in Philadelphia, he explained how “he had managed to amplify the DNA available from a single embryonic cell to identify complex diseases and also certain physical traits.” In many instances, being able to determine the presence of fatal diseases can assist prospective parents in avoiding the heartbreak of losing a child after birth. Many doctors are still on the fence about the idea saying that they understand the purposes of screening for genetic traits or disorders but feel the selecting gender or physical traits is “playing God”. Dr Kearns says, “I am not going to do designer babies.” What is your opinion on the issue?