Prenatal diagnosis and interdisciplinary care for Tay-Sachs disease

Prenatal Genetics: Tay Sachs Diagnosis

Rita Trosack (43) and her husband Peter (46) tried for two years to conceive a child. Rita is pregnant; other than advanced maternal age there are no maternal characteristics suggesting a high risk pregnancy. Because of advanced maternal age, CVS was suggested to screen for fetal birth defects. The CVS indicated that the fetus is afflicted with Tay-Sachs disease. Both parents are vacillating between denial and acceptance. Rita is engaging in self-blame, convinced that her hard work somehow caused the genetic disorder. Peter is angry and wants to believe that the test is wrong. At this time, the parents are unwilling to consider the possibility of abortion. There is a history of unexplained early childhood death.

Interdisciplinary Team

In any scenario where it is expected that a child will have a chronic, fatal, genetic childhood illness, it is important to assemble an interdisciplinary team to deal with issues related to that diagnosis. The first member of the team is obviously going to be the woman's high-risk obstetrician. The second member of the team will be a genetic counselor. The third member of the team will be a pediatrician who specializes in dealing with children with Tay-Sachs. The fourth member of the team will be a grief counselor. I will be the fifth and final member of the team, and I will coordinate the educational efforts of the specialists involved in the team.

I chose the high-risk obstetrician for two reasons. First, I am employed by the high-risk obstetrician and working as a representative for him. He will be the Trosacks' primary medical specialist throughout her pregnancy, and will be in the best position to monitor maternal health and depression during the pregnancy. I chose the genetic counselor because the Trosacks appear to have a limited understanding of the science behind genetic disorders, and they need to understand why their baby has this disorder and the risk for future pregnancies. I chose a pediatrician who specializes in Tay-Sachs so that the Trosacks would have information about what to expect with disease progression, treatment methods, and the lack of a possibility of a cure. I chose a grief counselor because the diagnosis of a genetic disease, even one that does not cause fetal death, brings with it the loss of the expectation of a healthy baby. Finally, I chose to be part of the team because it is my responsibility to coordinate information and appointments among the various specialists, and I can only do that as an integral member of the team.

Each member of the interdisciplinary team will provide unique resources for the Trosacks. The high-risk obstetrician will be able to provide information about the progression of the pregnancy. There is nothing about Tay-Sachs that suggests a more difficult pregnancy than normal, but advanced maternal age comes with its own risks. He will provide information about regular testing, diet, checkups, supplements, and other normal concerns. He will also closely monitor blood pressure and blood sugar, since preeclampsia and gestational diabetes are two concerns for older mothers.

The genetic counselor will provide this most information for the Trosacks. The counselor will explain how Tay-Sachs is diagnosed and the possibility of any false positives. The counselor will explain whether or not a Tay-Sachs diagnosis can differentiate between the three forms of the disease. The counselor will explain whether or not the disease is linked to gender, and the likelihood that future offspring will have the same disease. The counselor will also make it clear that the mother did not somehow cause this disease, by demonstrating its underlying genetic causes.

The pediatrician's job will be to give the parents an accurate forecast of what having a child with Tay-Sachs disease will entail. This will involve an explanation of any precautions that need to be taken with delivery, and whether a neonatal specialist needs to be involved in that process. It will also involve an explanation of milestones, and when and if the child will fail to meet those milestones. The pediatrician will explain special care concerns that will develop as the disease progresses. Most significantly, the pediatrician will explain average life quality and quantity for the child born with Tay-Sachs.

The grief counselor's job is to help the parents deal with their emotions. The mother's guilt and the father's anger are both normal responses to grief. Even if the parents choose to have the child, they will experience the loss of their expectations for that child. The grief counselor will inform them about the stages of grief and what to expect in each of those stages. The counselor will also talk about grief for parents with a dying child.

I will be the fifth and final member of the interdisciplinary team. My job will be to coordinate the impact of the other team members. I will synthesize the information provided by the other team members and formulate a teaching plan. I will be the first-point of contact for questions and answers. Though I will be able to provide information from my nursing background, my main role will be to coordinate other team members.

Teaching Plan

Genetic diagnosis

Tay Sachs "is a genetic disorder caused by the absence of a vital enzyme known as Hex-A. The missing enzyme causes cells to become damaged, resulting in progressive neurological disorders. A cure for Tay-Sachs does not yet exist but there are many strategies for managing life with Tay-Sachs" (National Tay-Sachs & Allied Diseases). There are three forms of Tay-Sachs, but only one form appears in each family. Classic infantile Tay-Sachs onsets around 6 months of age, juvenile occurs anytime during childhood, and late onset appears in adolescence or early adulthood. Anyone can be a carrier of Tay-Sachs; the carrier rate for the general population is 1/250, though certain ethnic groups have higher risks (National Tay-Sachs & Allied Diseases, 2011). The highest risk groups are French Canadians, Louisiana Cajuns and (Ashkenazi Jews National Tay-Sachs & Allied Diseases, 2011). Children cannot have Tay-Sachs unless both parents are carriers, and when both parents are carriers, each of their children has a 25% chance of having the disease (National Tay-Sachs & Allied Diseases, 2011).

Treatment

There is no real treatment for Tay-Sachs disease, though treatments can help alleviate symptoms. These treatments will largely depend on the family's goals. They may include life extending interventions like feeding tubes, or they may be comfort measures like massage. The two main aspects of treatment for infantile Tay-Sachs are respiratory health and seizure management, as breathing problems and seizures are the two most significant health concerns. Anticonvulsant medicine may control seizures initially (National Institute of Neurological Disorders and Stroke, 2007).

Pregnancy information

Tay Sachs disease is not symptomatic during pregnancy. Therefore, the patient's pregnancy will be managed like a normal high-risk pregnancy because of maternal age. Blood pressure and blood sugar will be monitored at all visits. Any indications of preeclampsia or gestational diabetes will trigger additional pregnancy treatment. During the first and second trimesters, prenatal visits will occur approximately every four weeks. In the third trimester, these visits will increase to every two weeks, and past 36 weeks the visits will become weekly. During pregnancy, the mother should moderately increase calorie assumption, reduce or eliminate caffeine usage, avoid alcohol and drug, including legal drug use unless advised by a doctor, engage in moderate exercise, and take prenatal vitamins. If the mother has symptoms associated with pregnancy, including morning sickness, eating before getting out of bed, sipping ginger-ale, and using Sea-bands may help alleviate those symptoms.

Ethical Implications

The ethical implications of the availability of the personal genetic information are significant. First, genetic testing has significant limitations. Second, genetic testing may provide information about diseases where no treatment or intervention exists. Third, genetic testing may lead people to make undesired choices. All three of these implications make some people question whether genetic testing is appropriate.

The first problem with genetic testing is that it has limitations. When testing parents, genetic testing can only identify possible diseases. For example, if both parents are carriers of Tay-Sachs disease, testing them can reveal that a child has a 25% probability of developing the disease, but not actually predict whether a particular child will have the disease. Moreover, some genetic testing is inaccurate, creating the possibility of false positives and false negatives.

The second problem with genetic testing is that it can provide information about diseases where there is no treatment or intervention. This is the case for Tay-Sachs. There is no way to prevent the disease, which is fatal in children. However, unlike some other genetic disorders, the baby is born healthy and begins to deteriorate sometime after birth. Does knowing that the child will develop the disorder help the family, when prenatal screening does nothing to help treat the child?

The third problem with genetic testing is that it may lead people to make undesired choices. Abortion rates for children with genetic diseases are higher than those rates for children without those diseases. Abortion is a major moral issue in the United States. Does a process that might increase the likelihood that a mother will choose an abortion create an ethical issue? Likewise, would refusing to allow parents, particularly carriers, to have prenatal genetic testing, and choose to terminate a child who will be born with a fatal childhood disease, create an ethical issue?