Inheritability of Genetic Disease

¶ … infertile couples turn to in vitro fertilization to try to have a baby. In this technique, sperm and egg are collected and used to create eight-cell embryos for implantation into a woman's uterus. At the eight cell stage, one of the fetal cells can be removed without causing harm to the developing fetus. Once removed, the cell can be genetically tested. Some couples may know that a particular genetic disease runs in their family. They might wish to avoid implanting embryos with the disease-causing genes. What if couple wanted to use genetic testing to select embryos for traits unrelated to disease, such as freckles or may be to select a gender. Do you think that couples undergoing in vitro fertilization should be allowed to perform whatever genetic tests they wish? Or do you think that there should be limits on what tests can be performed?

I strongly believe that there should be limits placed on the types of genetic tests that parents can perform on developing fetuses conceived through in vitro fertilization. Several substantive considerations influence my position, including these: Historically, human beings have not shown themselves to be good of genetic testing, nor have they demonstrated the capacity to consider the far-reaching implications of their decisions related to genetic testing. Selecting developing fetuses for implantation based on the probability of particular physical likenesses or appearance attributes calls into question the aptitude and intention of the prospective parents for their new roles as the primary protectors and nurturers of children for whom they assume responsibility. One has only to look at the history of childbearing and infanticide in China, say, or any number of unenlightened developing countries to see how easily and how badly this type of practice can support very wrong attitudes toward children and women.

I absolutely do believe that prospective parents should have the right to authorize tests that can illuminate the presence of genetic markers for disease or disability, and then forbid implantation of developing fetuses that do not prove to be clear of genetically associated disease or disability. Under the normal processes of fertilization and conception, the female reproductive organs may function so as to curtail full gestation of fetuses that have genetic flaws such as birth defects. Sophisticated techniques for supporting conception may interfere with some of those normal processes. Still, the fact remains that there are tremendous emotional and economic costs associated with giving birth to babies who have disabilities or are exceedingly likely to develop particular diseases in their growing up years. It does seem fair for parents to make this type of heart-wrenching decision in -- as much as possible -- an informed manner.

TOPIC 2: Although it is strongly suggested that a woman not drink alcohol during her entire pregnancy, why is this advice particularly important during the first semester?

The first trimester of fetal development is a time when the major organ systems are being established, and the sensitivity of cellular structures is at an all-time high with respect to mutation or deformity. Consider that the impact of alcohol on developing fetuses is dependent upon a range of factors, many of which are neither apparent to the expectant mother nor particularly amenable to intentional efforts to decrease risk. It is simply not possible to describe an absolutely safe amount of alcohol consumption for all babies in utero, or for all expectant mothers across all conditions and contexts. Much of the data available about ingesting alcohol during pregnancy comes from the longitudinal studies of children suffering from Fetal Alcohol Syndrome (FAS) or Fetal Alcohol Affects (FAA), which reflects a less debilitating condition on the FAS spectrum. FAS is a long-term, irreversible condition that results in the characteristic physical markers of the syndrome and serious effects such as smaller heads, heart and joint deformities, behavioral and learning difficulties. The brain of an unborn baby is very sensitive to alcohol consumption of the mother, and the risk is highest during the second half of the first trimester.

TOPIC 3: Young Liam, a male, is afflicted with a muscle wasting disease. His mother's two brothers also had the disease. No other family members (his father, his father's relatives, his mother, or his mother's female relatives) have the disease. Is this muscle wasting disease (A) autosomal or sex-linked, and (B) dominant or recessive? Defend your answers.