Genetic counseling

| Main Article
| Discussion
| Related Articles  [?]
| Bibliography  [?]
| External Links  [?]
| Citable Version  [?]

|
|
|
|
|
|
|
|

This editable Main Article is under development and subject to a disclaimer.

[edit intro]

Genetic counseling is an educational activity performed by physicians and allied health science professionals for clients who have either a condition or genetic or chromosomal variation that may cause them harm, or have a condition that may be passed on to their children and cause them harm. Sometimes, the point of the counseling session is to discuss the tests that are required to determine whether or not such a condition exists, and so many people see a genetic counselor who turn out not to have a genetic abnormality, after all. The fact that a person is a client does not mean that a diagnosis has already been made. For example, older women are at high risk for bearing children with chromosomal abnormalities, and, in many parts of the world, women in their late thirties and forties, and older women, routinely have genetic counseling as part of prenatal care.

In sharp distinction to the interactions between patients and health care professionals during the Eugenics movement, clients are informed of their chances of passing on inherited diseases and conditions without any mandatory intervention. In sone cases, genetic counseling is directed at the patients themselves, when test results indicate the presence of a gene or chromosomal abnormality that may affect the patient's health, for example, with an increased risk of cancer. Most formally, genetic counseling is the province of physicians who are human geneticists, and of health professionals who are certified genetic counselors, the former bound by the ethics of having a physician-patient relationship with the client, and the latter bound by a set of professional ethics that insist on neutrality and client choice. As an activity, genetic counseling was named by the geneticist Sheldon Reed in 1947, to distinguish the identification and education about genetic conditions to potential parents from the pseudoscientific coercion of reproductive choice that had been imposed by eugenecists. As a profession, genetic counseling has been recognized since about 1975.

Reed was a humanist who argued that patients were legitimately informed of the medical consequences of childbearing but that the ultimate choice of whether or not to bear children was up to them, and not to the physician or any state authority. At the time he practiced, the ability for adults to control reproduction by amniocentesis and selective abortion did not exist. Basically, those individuals who were at high risk for passing serious conditions either remained childless by being celibate or using birth control methods with abortion of any pregnancy. Those parents who chose to have children benefited from an ability to better prepare for the needs of impaired infants, and their families.

## Contents

* 1 Assessing the problem: pedigrees and laboratories
* 1.1 Cytogenetics
* 1.1.1 Balanced translocations
* 1.2 DNA tests
* 2 Current role of genetic counseling in health care
* 2.1 Huntington's disease (Huntington's chorea)
* 3 Example of conditions in which genetic counseling can be important
* 4 Current issues in assisted reproduction and genetic counseling

## Assessing the problem: pedigrees and laboratories[edit]

When Sheldon Reed first defined genetic counselling, there were few laboratory tests available to confirm genetic diagnosis in parents and there was no way to test an unborn fetus. However, there were some medical conditions that were known to have a classic mendalian mode of inheritance, and there were parental characteristic, like advanced maternal age, that were known to put a couple at risk for having children with certain conditions, like chromosomal defects. Over the last fifty years, there have been tremendous advances in human cytogenetics and, most especially, in DNA tests for specific abnormalities. The quality of the laboratories performing these tests and the interpretation of the results of the tests in the context of the client's clinical circumstances are vital aspects of the accuracy of the predictive value of results.

### Cytogenetics[edit]

The cytogentics laboratory makes carefully stained karyotypes of patient's cells.

#### Balanced translocations[edit]

### DNA tests[edit]

## Current role of genetic counseling in health care[edit]

These conditions have been chosen to illustrate some of the major issues faced in genetic counseling. The ethical stance of the geneticist, can be summarized by the following quote from Judith Hall, physician, professor and head of the Department of Pediatrics, at the University of British Columbia and British Columbia's Children's Hospital, Vancouver, ""Geneticists in Canada don't tell people what to do. We just don't think that's right. In fact, our code of ethics specifies that we be nondirective," Hall says. "That means we help people absorb information and come to a decision that's right for their families. For one family this will be terminating a pregnancy; for another it will be maintaining that pregnancy. For one family it'll be sterilization; for another it'll be taking their chances. One family will use prenatal diagnosis; another won't. One will get all the members of the family together to talk about it; another won't be able to bring themselves to talk about it. Different families are different. I guess genetic counsellors feel strongly that if families receive information, and they understand it, they'll reach decisions that are right for them."(Robinson A. Genetic diagnosis: present and prospects. CMAJ Canadian Medical Association Journal. 150(1):49-52, 1994 Jan 1. UI: 8275409)

### Huntington's disease (Huntington's chorea)[edit]

## Example of conditions in which genetic counseling can be important[edit]

## Current issues in assisted reproduction and genetic counseling[edit]

The specter of the Eugenics movements still hangs over current issues in reproduction. These issues are particularly acute in couples who believe in choice for abortion and high tech assisted reproduction, and who desire children but plan a limited number of offspring. In such cases, especially when there is a family history of genetic disease, parents may not be willing to accept a pregnancy without checking for a diagnosis that may mean the baby will either die in infancy or have a severe disease or disability. In the cases of recessive genes, where each parent is known to be a carrier, then -if tests exist for the gene, embryos or early placental material may be tested for the presence of the gene. If the conceptus is homozygous for the gene, then there is medical certainty of the disease, and parents may choose to end that pregnancy. Although people who believe that this is akin to infanticide may choose not to end the pregnancy, and instead to have the baby, even then they have forewarning of what to expect. Depending on the exact disease, this may improve the life of the ill infant, and mitigate the impact on other children in the family, or be faced with results of such tests that indicate probabilities only and no real certainty of extreme disability. For example, the most common abnormalities in chromosomal number (aneuploidy) include Down syndrome and Turner syndrome.

Even more controversial are tests for conditions in which there may be a specific isolated disability, like sensory hearing loss so severe as to preclude normal speech and language development without a cochlear implant, but unlikely to cause any other problem.

With the ability to test for genetic and chromosomal abnormalities that are associated with disease, many fathers, mothers, and physicians struggle with the ethical implications of selective reproduction.