Genetic Disease: Diagnosis, Screening, Treatment, and Decision Making - Case Study Example

TROSACK'S GENOGRAM Polish origin Irish origin It is clear from the information given, that there is no history of Tay-Sachs from Peter's mothers' side of the family. However, Peter's father carried the recessive gene for Tay-Sachs disease. Peter's paternal aunt and uncle died at a very young age of unknown cause - they both may have died of Tay-Sachs disease. This means that both paternal grandparents of Peter were carriers of the recessive gene. Peter also inherited one recessive gene and has become a carrier The family history information rules out the gene for Tay-Sachs from Rita's mothers' side. Rita's father is a carrier of the recessive gene for Tay-Sachs disease and both her paternal grandparents were carriers too, it is rather evident because, of their two sons, one died of an unknown cause at a very young age, could have been from Tay-Sachs disease. Rita inherited the recessive gene from her father and became a carrier. Since both Peter and Rita are carriers for the recessive gene, there is a 25% chance that their child could well be suffering from Tay-Sachs disease. The screening test (CVS) for fetal genetic defects confirmed that the fetus was indeed afflicted by the Tay-Sachs disease. Analysis of the Genogram: Rita (43 years) and Peter (46 years) have been trying to have a baby for more than 2 years, Rita has conceived now. There is sufficient documentation to show that the peak fertility period for women is between 20-24 years of age, after which it begins to decrease and this explains the delayed conception. The website www.babycentre.co.uk states that "According to the Human Fertilisation and Embryology Authority, "At 35 you're half as fertile as when you were at 25; at 40 you're half as fertile as when you were 35". This means that it can suddenly take much longer to get pregnant when you hit your late thirties or early forties and you may have problems conceiving at all." The same website also includes information on the risk of genetic disorders with advancing age Another problem is that the odds of having a baby with a genetic defect increase as you get older. Figures from the Office of National Statistics for 2005, show that the risk of having a baby with a genetic abnormality such as Down's syndrome rises from 2 per 1,000 births at ages 35-39 years, to 4 per 1,000 at age 40-44 years up to 14 per 1,000 at age 45 years or over. If you're almost, or over 40, you should strongly consider genetic testing because the risk of genetic problems increases significantly. Both Rita and Peter have crossed their peak fertility age and are therefore in the high risk category for genetic disorders. The physician, ordered for a CVS to rule out any genetic defects in the developing fetus. The genetic screening pointed to Tay-Sachs in the fetus. Prior to this genetic screening neither Peter nor Rita ever suspected that they could be carriers for the Tay-Sachs disease. The Tay-Sachs disease is an autosomal recessive disease which is a result of mutation in both the alleles of the gene Hex-A seen in chromosome 15. As a result of the mutation, an enzyme called Hexosaminidase A is either not produced at all, or, is not produced in sufficient quantity. This insufficiency leads to an abnormal accumulation of a lipid called GM2 ganglioside in the nerve cells especially in the brain leading to progressive damage of the cells and eventual death of the cells. Children who suffer from this disease usually die before the age of five, because, by this age the nervous system is so seriously affected that it cannot support life. Knowing that it is a recessive gene that causes the disease, is good news for the Trosack couple. A recessive gene can express itself in a particular generation only if it is present in a double dose, this occurs only if the progeny has inherited the recessive gene from both its parents. The chance of the couple passing on the recessive genes to their progeny, so as to exhibit the condition is only 25%. This means that the chance of the Trosack couple having a child not affected by the Tay-Sachs disease is 75%. The probability of the couple having a normal child is 25% while the chances of them having a child who will be a carrier (just like them, their fathers and their paternal grandparents) of the recessive gene is 50%. The diagram illustrates the way genes are inherited from parent to offspring. RR - Normal child (25%) Rr - Carrier child (50%) rr - afflicted child (25%) Unfortunately, in this particular pregnancy, the fetus has inherited the recessive gene from both Rita and Peter and therefore expresses the Tay-Sachs disease. It is a well documented fact that most children affected by this disease do not survive beyond the age of five. The Inter-disciplinary Team & Ethical Implications: This CVS has confirmed that the fetus of the Trosack couple is affected by the Tay-Sachs disease. To be able to guide the couple on what future course of action they should take, I would first contact a consulting Medical Physician specialized in the treatment of genetic diseases specifically Tay-Sachs disease who would be able to provide authentic information on: what the disease is - what are the causes, symptoms, severity of the disease How is the disease transmitted - is it a genetic disorder that can be inherited, how the disease spreads, how common it is what the latest diagnostic tools are - what are the testing procedures, how relevant and accurate are the results treatment options currently available and the success rates of these treatments The Trosacks are aware that their fetus is afflicted by the disease, but are in denial and refuse to consider abortion because of their personal and religious choices. The couple does not have sufficient information about the disease and are therefore having doubts about whether Rita would ever be able to conceive again, they may have also formed uninformed opinions about the probability of having a normal child. Only an expert in this field - a Gene therapist / Counselor - would be able to help them through this difficult phase. A Gene Counselor would be able to guide them through about the consequences of going ahead with the pregnancy in spite of knowing that the fetus has Tay-Sachs. The Counselor would also be able to provide them information on the probability of having normal children in subsequent pregnancies, whether they need to go in for assisted pregnancy, in-vitro fertilization or other such techniques. Both Rita and Peter were raised as Catholics, though as of now, neither practises their religion. Catholics, in general, do not view abortion as a rightful choice, and this is leading to more sadness and confusion in the couple. They are desperately looking for answers - why them could the tests have been wrong what did they do to deserve this In times of stress, people do look to God for answers and strength. Talking to a Church Leader / Head would help them in this moment of grief and sadness, and help them take a conscious and well informed decision about continuing or terminating the pregnancy. There are also legal and ethical issues concerning genetic screening and the couple must be fully aware of their rights. The couple should be aware that they cannot be discriminated in the work place because of their genetic disposition, they cannot be discriminated against for insurance procedures and mechanisms based on their genetic data. Meeting a Medico-legal consultant would be advisable for the Trosack couple because they are in a highly competitive work environment. Genetic information is personal and this must not be used for profit or discrimination. There are several ethical issues that come up with availability of genetic information. Human and family relationships evolve over time and are very dynamic, specific knowledge about certain genetic dispositions especially relating to emotional and psychological aspects or reproductive health could cause or result in disruptions in the family setup. Availability of such information to employers could also be potentially dangerous as it could be used for weeding out people who could cause disruptions at the work place. Employers often like to hire people, who are emotionally and mentally stable, physically fit, work efficiently, use less resources/services (medical benefits, leave, insurance facilities etc). Genetic information indicating a susceptibility or predisposition to any disorder could put the employee in a compromising situation. On the basis of genetic information, it is possible that Insurance companies hike the premium, refuse to provide cover to certain individuals or communities. When patients go for genetic counseling, it is true that they are looking for advice and support to make a conscious and well thought out decision. How ever, when the opinion/ decision of the Counselor do not match with the views of the patient/ family, how unbiased and supportive will the Counselor be Should the Counselor take a proactive role in the decision making or should they just provide unbiased information and leave it to the patient to make the final choice/ decision. This is an ethical question that confronts counselors and patients alike. The Teaching Plan & Decision Making: The result of the CVS is not favorable to the Trosack couple, the fetus tested positive for Tay-Sachs disease. There is evidence that has been collected from the family history of the couple. In both the families (paternal side only) infantile death has been reported, due to unknown cause. Tay-Sachs disease is an autosomal recessive genetic disorder and is exhibited only when both the parents are carriers of the recessive gene. Though individual testing has not been done for Rita and Peter, it is quite evident that they are both carriers of the recessive gene, they both inherited it from their respective fathers. Children born with this disease get progressively worse and suffer from several severe disabilities - paralysis, dementia, blindness and early death. Death is a result of excessive and abnormal accumulation of GM2 ganglioside in the brain cells. The couple needs to be informed that their child would go through a lot of pain and agony and in all probability, would not survive beyond the age of five. There is continuous research and testing to develop a cure for this disease, most promising among them being Gene therapy, molecular or pharmacological chaperone therapy and neural stem cell therapy. How ever, these are still in the research phase. As of today, there is no cure for this disease. If detected and diagnosed at the fetal stage the best option available to parents is termination of pregnancy. Both Rita and Peter are carriers of the recessive gene, how ever, the chances of them having a healthy baby, not affected by the disease is 75%. Considering their advanced age, if the couple are not able to conceive within a period of 6 months after termination of this pregnancy they could opt for assisted conception - artificial insemination from a non carrier sperm. If in-vitro fertilization is opted for, then, pre-implantation genetic diagnosis (PGD) could be done to ensure that only a healthy and viable embryo is implanted. With the advancement in genetic screening, medical diagnostic procedures, assisted conception techniques and procedures and pregnancy management there is no need for the Trosack couple to feel insecure or have doubts about giving birth to a healthy baby. It would be advisable for them to contact the National Tay-Sachs and Allied Diseases Association, Inc., to meet with other parents and support groups who would help them overcome their fears and doubts about the disease and help them come to terms with their reality without having a feeling of guilt. The support groups would help them understand that they were not physically or morally responsible in any way for their child to have developed the disease, it had nothing to do with their lifestyles or beliefs but was the result of a gene mutation resulting in a defective gene that they have inherited from their ancestors! This would also help them take a conscious decision that would be in the best interest of everyone concerned. Decision regarding termination of pregnancy, if taken, will have to be done before the beginning of the 2nd trimester since risk to the mother increases exponentially if done after the 1st trimester. The couple could then go to a fertility clinic and take the advice of a qualified Medical Consultant on what options are available to them to carry a pregnancy to term. I would support the couple's decision if they opted for termination of pregnancy immediately. There would be untold suffering at various levels and degrees - physically, emotionally, psychologically, financially, socially, medically - both for the couple and the baby if they went ahead with the pregnancy. All this suffering and pain just to lose the child in less than 5 years, not worth the effort. Instead, using the aid of science and technology they could conceive a healthy baby and carry it to full term, certainly a more wise and progressive decision based on rational thinking and practical approach to life. Medical science is all about providing relief from suffering and ill health and I would advocate this for any couple going through this dilemma. In fact this is a decision I would take even for myself, if I am ever faced with such a situation. How ever, in spite of the overwhelming reasons to terminate the pregnancy, if the couple does decide to go ahead with the pregnancy, I would respect it and provide them all the necessary medical support and assistance during the pregnancy as well as during birth, after which, of course, they will have to consult a pediatrician. It would how ever, be a difficult situation to handle if either Peter or Rita decide differently - if one wants the pregnancy and the other wants to terminate it, the underlying complications to this would be far too great to handle (their personal relationship, financial implications, emotional stress) and is beyond the scope of this paper. This is both an ethical and legal question. Whose decision must be respected - the mother's or the father's Who takes responsibility for the decision How would this decision affect the future of their relationship Who should compromise so that they arrive at a common decision that would be in the best interest of all concerned Would they be able to arrive at a common decision These are very personal questions but definitely have implications at the personal societal, legal and policy level, and therefore must be discussed and debated well. REFERENCES 1. Jenkins Jean. (2001). Ethics: Ethical Implications of Genetic Information. The Online Journal of Issues in Nursing. A Scholarly Journal of the American Nurses Association, Volume 6-2001, No.2 May 2001. Retrieved December 3, 2009 from http://www.nursingworld.org/MainMenuCategories/ANAMarketplace/ANAPeriodicals/OJIN/TableofContents/Volume62001/No2May01/EthicalImplicationsofGeneticInformation.aspx#Jenkins 2. http://www.ntsad.org/ Retrieved December 3, 2009 3. http://www.babycentre.co.uk/preconception/activelytrying/ageandfertility/ Retrieved December 3, 2009 4. http://www.babycentre.co.uk/preconception/beforeyoubegin/risksafter35expert/ Retrieved December 3, 2009 Read More