Genetic Disorders and the Fetus. Группа авторов

is inadvisable for a couple (or individual) considering predictive testing. During the counseling session with full information transfer, an assessment of emotional health should be made. For many, a consultation with a psychologist or psychiatrist would be wise before a follow‐up visit to determine the decision to test or not, and to obtain informed consent.

      Many at risk of developing Huntington disease choose not to be tested. In a study of 733 individuals who did not wish to learn if they harbored this fatal flaw, 66 percent pointed to lack of a cure or treatment, and 66 percent to the inability to undo information provided.³⁶⁰ Only 12–17 percent of those at risk in North America and Europe pursue testing.^360–364 Family and extended family repercussions may occur as a consequence of a choice not to be tested in the face of a 50 percent risk.^365–367 Some family members may hold the untested who proceed to have children morally irresponsible.

      There is of course the right of every person not to know their genetic status as potential carrier of a serious genetic disorder. It is not the duty of a counselor to state or hint that it is a moral imperative to have a predictive test. Rather, the responsibility is to provide a perspective on the testing, the various options, and the disparate pros and cons.

Predictive testing of children younger than 18 years of age is proscribed except in life‐threatening disorders (e.g. long QT syndrome, multiple endocrine neoplasia type 2B). Given the remarkable pace of advances in human genetics, it may well be possible in the foreseeable future to develop a therapy that enhances the extant biologic mechanism already in place that delays the manifestations of later onset disease for decades after birth. No life should be ruined by severe depression or suicide only to discover later that a critical palliative remedy has emerged.

      No longer hypothetical is the prenatal diagnosis request by a pregnant mother for fetal Huntington disease without the knowledge of her at‐risk partner who does not wish to know his genetic status. In preserving the partner's autonomy and recognizing maternal rights, we have in the past honored such requests. Mothers have, in these circumstances, faced with an affected fetus, elected to terminate the pregnancy, invoking miscarriage as the reason to her unknowing partner. Distressing as it is to contemplate such a marital relationship, textured on the one hand by extreme care and on the other hand by deceit born of sensitivity, consider our report of symptomatic juvenile Huntington disease at 18 months of age and diagnosed at the age of 3 years.³⁶⁸ These cases pose challenging ethical, moral, and legal questions, but both prenatal and preimplantation genetic testing (see Chapter 2) are now well accepted in the Western world.^369–371 Certainly rigorous recommendations and guidelines are in place for the prenatal diagnosis and the preimplantation genetic testing for Huntington disease,³⁶⁹ which would apply equally to other neurodegenerative disorders and serious/fatal adult‐onset disorders.

      In general, the post‐prenatal testing behavior of the mother is not likely to escape the average paternal observer. In a study of 54 women whose fetal risks of being affected were 50 percent (that included spouses of an affected partner), after an initial unaffected pregnancy, 10 percent chose not to have prenatal testing in a subsequent pregnancy.³⁷²

      Prenatal diagnosis is not recommended for couples who do not intend to terminate a pregnancy if the fetus is affected.³⁷³ A contrary view holds that diagnosis of a fetal genetic disorder may well inform the subsequent management of labor and delivery. Continuation of that pregnancy would likely remove the autonomous right of that child to decide to be tested or not.³⁷⁴ In a review of 15 such pregnancies, one guideline was to recommend that couples should not disclose the diagnosis in order to protect the confidentiality and autonomy of the future child.³⁷⁴

      Clearly, there are extraordinarily difficult circumstances related to planned childbearing in the face of 50 percent risks for a neurodegenerative disorder coupled with a wish not to know. In these special circumstances, predictive testing can be regarded as acceptable only if performed with extreme care, concern, and professionalism.

      Preconception care should begin during visits to the family physician after menarche. Reiterated and expanding discussions on personal health habits that will affect both the adolescent herself and a future child, provide a basis for promoting good health behavior, while a solid grounding in knowledge about the hazards of smoking, drugs, alcohol, sexually transmitted diseases, and nutrition is provided. Early adolescence is also a vital period during which to inculcate the importance of genes and the wisdom of assimilating and updating information on family history. Linkage of family history to the common experience of physical and mental handicap, outlined in the context of personal risk in childbearing, provides a compelling and cogent framework on which physicians, teachers, and parents can build.

      This preparatory background may help educate all women about the importance of planning pregnancy. Over 50 percent of pregnancies in the United States are not planned and are often unintended.³⁷⁵ Physicians also need to reorient their practices so that women of childbearing age understand that to optimize the chance of having a healthy child,³³⁵ prenatal care is best initiated before conception and not after the second missed menstrual period, as is still anachronistically practiced so widely.

      Duty to warn

Physicians and counselors traditionally owe no duty to individuals with whom they have never met or entered into any treatment relationship. However, following the decision of the California Supreme Court (in Tarasoff v. Regents of the University of California),³⁷⁶ it has become clear that when a serious risk to the health or life of a third party is recognized, a duty of reasonable care evolves that demands protective action. Examples include contact with blood relatives at risk in situations of threatened violence, exposure to infection (HIV/AIDS), and now harmful genes. For colorectal cancer there is evidence that over 50 percent of families at risk do not receive the necessary information.^377–379 A salutary lesson is provided in the study of 43 families with at least one sudden unexplained death.³⁸⁰ Identification of a genetic cardiac disorder (e.g. long QT syndrome) was made in 40 percent of the families who harbored 151 presymptomatic carriers! The loss‐of‐chance legal doctrine makes it incumbent upon geneticists/counselors to impress on their patients the need to warn blood relatives if a serious genetic threat is determined. This counsel should be in writing and documented in the medical record. Litigated examples include failure to warn of the risk of medullary thyroid cancer, familial adenomatous polyposis with colon cancer, and the fragile X syndrome.³⁸¹ From the judicial opinions in these cases³⁸² we learned that: (i) moral duty is not equal to legal duty; (ii) the duty to one's family members of avertible risk serves the interests of justice; (iii) given precedents of third party disclosures in the fields of psychiatry and infectious disease, there has been a willingness to extend the duty to warn.

      Sudden death as a consequence of a monogenic disorder invokes specific responsibilities not only by the pathologist performing the autopsy but also the geneticist or genetic counselor, if involved with the family. Determination of the cause of sudden death, if not clearly obvious, may be ascribed to an arrhythmia. Cost issues aside, there is the need to consider gene sequencing for the long QT syndrome, the Brugada syndrome, and catecholaminergic polymorphic ventricular tachycardia. At the very least, a tissue sample should be frozen without preservative for subsequent DNA studies. Where cardiac pathology points to a cardiomyopathy, similar considerations pertain. Counseling of next of kin in such cases is important, more especially since they may face a 50 percent personal risk. On occasion, a patient at high risk may refuse to be informed about a specific genetic test result. However, if that result implicates a specific disorder that not only places that individual at risk but as a consequence may cause harm to others, the ethical imperative would demand communication of that unwanted information.³⁸³

      Important legal precedents serve as further guidance. In the Pate v. Threlkel case (1987),³⁸⁴ the mother of Heidi Pate was diagnosed and treated for the autosomal dominant form of medullary thyroid cancer. Three years later, the same diagnosis was made for Heidi. She sued her mother's physicians asserting that they