CAN GENOME SEQUENCING BE USED TO IDENTIFY OTHER MUTATIONS, BEYOND CHROMOSOMAL ABNORMALITIES, THAT MIGHT CAUSE DISEASE?
With the higher sensitivity and lower cost of high-throughput sequencing, it is now possible to determine the whole genome sequence of a fetus before it is born. Although it is likely that genome sequencing of fetal DNA obtained from the mother’s blood would be less accurate than that of fetal DNA from the fetus itself, prenatal genome sequencing nonetheless provides an opportunity to noninvasively predict disease risk before a child is born. The issues this testing raises are similar to those raised above for any healthy person, but there are also important differences. One significant difference in prenatal screening compared with newborn, child, or adult genetic screening is that parents can choose to terminate the pregnancy. As discussed in more depth later, several ethical issues arise: What level of confidence is required for prenatal screening in order to terminate a pregnancy? Is it appropriate to screen for and act upon nondisease conditions, such as height or hair color? Even if the fetus is diagnosed with a disease risk and the parents decide to continue with the pregnancy, the knowledge of the disease risk might affect the manner in which the parents treat or behave around the child after birth. Parents may become overly concerned or overly protective if they believe their child is at risk for particular conditions. In some cases this behavior may prove beneficial, but in other cases, overprotective behavior may be harmful.