The "Critical Element of Genetic Evaluation and Genetic Counseling" was written and approved by genetic professionals and perinatologists within the state of Washington. The document is to act as an aid to medical geneticists, genetic counselors, and perinatologists who practice within our state. This Critical Element of Genetic Evaluation and Genetic Counseling does not define the applicable standard of care, nor is it intended to dictate an exclusive course for the diagnosis, counseling, treatment or management of genetic conditions or birth defects. The authors acknowledge that appropriate clinical practices may vary depending upon a number of factors including, among others, the needs and choices of the individual patient, the resources available, and limitations unique to the particular institution or type of practice.

1. Review patient/family questions; reason for referral; knowledge base; perception of disease status and/or risk; what diagnoses have been considered; perceived notion about causation; assess need for professional interpreter: presymptomatic patient: refer to presymptomatic CE

2a. Using standard symbols, obtain family history (1st and 2nd degree relatives to consultand, and further removed as appropriate). Note ethnic background, consanguinity, ongoing pregnancies, and other significant family history.

b. Additional directed family history: neurological diseases, uncontrolled movements, mental illness, age of onset of symptoms, ages and causes of death.

c. Obtain relevant medical records on patient, including records of 1).appropriate tests/evaluations: HD DNA testing, brain imaging, prior neurological exams, neuro/psych evaluations, genetic evaluations 2). records bearing on management: and 3). on other family members as needed: as listed for patient, autopsy (brain).

3. Obtain prenatal and perinatal history of patient, including prenatal exposures, pregnancy complications and prenatal testing, when appropriate.

4. Obtain past medical history (including environmental/occupational exposures) focusing on: changes in mental and physical functioning, depression, traumatic head injury, drug and alcohol use.

5. Obtain information on growth and development, including school placement. For adult, also obtain information on education, employment and social functioning: assess changes in job and driving performance, social/family functioning.

6. Assess family functioning and use of community resources. Assess personal, social, religious, ethnocultural issues.

8 Perform general physical examination of patient and/or other family members present if indicated, with attention to: neurological exam, mental status exam.

9. Other issues to consider:

(this may occur in a series of multiple patient visits)

1. Summarize information obtained and discuss with patient/family the (possible) diagnosis and the degree of certainty of the diagnosis based on available information: presymptomatic individuals should follow presymptomatic critical elements.

2. a). Recommend relevant tests/evaluations on patient and/or on other relatives which may include:

3. Discuss the following issues related to natural history: prognosis, developmental outcome/intellectual functioning, anticipated possible medical complications, including pregnancy related risks for affected women if indicated, and preventive measures:

4. Review inheritance pattern (including penetrance and expressivity): autosomal dominant, trinucleotide repeat; age related penetrance.

5. Assess and discuss recurrence risk for future pregnancies, for affected and at risk individuals. Discuss general background risk for birth defects and recommendations for preconceptional and prenatal use of 0.4 mg folate per day. Including any additional risk based on family history/ethnicity/maternal age/maternal disease/maternal exposure/others; discuss recommendations for preconceptional folic acid supplementation:

6a. Discuss reproductive options (e.g. assisted reproductive technologies, adoption, taking risk and no additional pregnancies) when appropriate: male affected: artificial insemination by donor semen; female affected: donor ovum.

b. Discuss prenatal diagnostic options/issues: in pregnancies at 50% risk: amniocentesis or CVS; see prenatal CE

(or referral for discussion of)

7. Review management recommendations/options including screening protocols:

8. Consider referral to: neurologist, speech and swallowing clinic, professional psychological support, referral for neuropsych evaluation.

9. Address psychosocial issues including anticipatory guidance, patient and family reaction to diagnosis, need for community support services: Disability resources

10. Address follow-up issues, such as genetic counseling for extended family members, including a plan for relaying test results: patient should return to clinic in 1-6 months to assess coping with diagnosis.

11. Document clinic visit, including persons present, and subsequent substantive contacts (e.g. clinic note, +/- letter to referral source, +/- letter to family; other). Contact referring health care provider as appropriate.

12. Other issues to consider: : Documentation of diagnosis in one affected family member by HD DNA testing is recommended. If HD DNA testing is done in another family member- that family member needs genetic services as outlined in applicable Critical Element. If patient is pregnant, simultaneous testing of patient and fetus is discouraged. Consider medical alert jewelry (so patient in not mistaken as under the influence of drugs or alcohol).

13. References and/or other protocols:

The "Critical Element of Genetic Evaluation and Genetic Counseling" was written and approved by genetic professionals and perinatologists within the state of Washington. The document is to act as an aid to medical geneticists, genetic counselors, and perinatologists who practice within our state. This Critical Element of Genetic Evaluation and Genetic Counseling does not define the applicable standard of care, nor is it intended to dictate an exclusive course for the diagnosis, counseling, treatment or management of genetic conditions or birth defects. The authors acknowledge that appropriate clinical practices may vary depending upon a number of factors including, among others, the needs and choices of the individual patient, the resources available, and limitations unique to the particular institution or type of practice.

1. Review patient/family questions; reason for referral; knowledge base; perception of disease status and/or risk; what diagnoses have been considered; perceived notion about causation; assess need for professional interpreter: Recommend support person be present at all visits. If asymptomatic minor, testing should be deferred until legal adult (see Neurology 1994, Bloch 1993, ASHG position statement on testing children, 1995).

2a. Using standard symbols, obtain family history (1st and 2nd degree relatives to consultand, and further removed as appropriate). Note ethnic background, consanguinity, ongoing pregnancies, and other significant family history.

b. Additional directed family history: neurological diseases, uncontrolled movements, mental illness, age of onset of symptoms, ages and causes of death.

c. Obtain relevant medical records on patient, including records of 1).appropriate tests/evaluations: prior neurological exams, neuro/psych evaluations, genetic evaluations 2). records bearing on management: and 3). on other family members as needed: HD testing, neurological exams, brain imaging, autopsy (brain).

3. Obtain prenatal and perinatal history of patient, including prenatal exposures, pregnancy complications and prenatal testing, when appropriate.

4. Obtain past medical history (including environmental/occupational exposures) focusing on: changes in mental and physical functioning, depression, traumatic head injury, drug and alcohol use.

5. Obtain information on growth and development, including school placement. For adult, also obtain information on education, employment and social functioning: assess changes in job and driving performance, social/family functioning.

6. Assess family functioning and use of community resources. Assess personal, social, religious, ethnocultural issues.

7. Assess possible ethical concerns, such as confidentiality, non-paternity, insurability, discrimination, prenatal diagnosis: evaluation of symptomatic minor; genetic counseling for any additional family members being tested concurrently; evaluation of individuals at 25% risk; prenatal testing.

9. Other issues to consider: consider documentation of diagnosis in an affected family member by HD DNA testing. If testing is done in another asymptomatic family member - that family member needs genetic services as outlined in this document.

(this may occur in a series of multiple patient visits)

1. Summarize information obtained and discuss with patient/family the (possible) diagnosis and the degree of certainty of the diagnosis based on available information: Symptomatic individuals should follow symptomatic critical elements. Before HD DNA testing, counseling should explore the impact of positive, negative and uncertain DNA results on the following areas:

2. a). Recommend relevant tests/evaluations on patient and/or on other relatives which may include:

3. Discuss the following issues related to natural history: prognosis, developmental outcome/intellectual functioning, anticipated possible medical complications, including pregnancy related risks for affected women if indicated, and preventive measures: a positive HD DNA test result does not give information about age of onset of symptoms, severity of symptoms nor prognosis.

4. Review inheritance pattern (including penetrance and expressivity): autosomal dominant, trinucleotide repeat; age related penetrance.

5. Assess and discuss recurrence risk for future pregnancies, for affected and at risk individuals. Discuss general background risk for birth defects and recommendations for preconceptional and prenatal use of 0.4 mg folate per day. Including any additional risk based on family history/ethnicity/maternal age/maternal disease/maternal exposure/others; discuss recommendations for preconceptional folic acid supplementation:

6a. Discuss reproductive options (e.g. assisted reproductive technologies, adoption, taking risk and no additional pregnancies) when appropriate: male affected: artificial insemination by donor semen; female affected: donor ovum.

b. Discuss prenatal diagnostic options/issues: in pregnancies at 50% risk: amniocentesis, CVS, option of non-disclosing prenatal diagnosis by DNA linkage for pregnancies at 25% risk.

(or referral for discussion of)

8. Consider referral to: neurologist, professional psychological support,

9. Address psychosocial issues including anticipatory guidance, patient and family reaction to diagnosis, need for community support services.

10. Address follow-up issues, such as genetic counseling for extended family members, including a plan for relaying test results: individual with positive results should be contacted shortly after being given results and offered a return clinic visit.

11. Document clinic visit, including persons present, and subsequent substantive contacts (e.g. clinic note, +/- letter to referral source, +/- letter to family; other). Contact referring health care provider as appropriate.

12. Other issues to consider: presymtomatic testing usually requires more that one visit. Visit 1: information and counseling, visit 2: neurological examination with additional counseling, Visit 3: results

13. References and/or other protocols:

Hayden MR, Kremer B (1995). Huntington Disease in Scriver CR et. al., (eds), The Metabolic and Molecular Bases of Inherited Disease, NY:McGraw-Hill, Inc., p.4483-4510.

The "Critical Element of Genetic Evaluation and Genetic Counseling" was written and approved by genetic professionals and perinatologists within the state of Washington. The document is to act as an aid to medical geneticists, genetic counselors, and perinatologists who practice within our state. This Critical Element of Genetic Evaluation and Genetic Counseling does not define the applicable standard of care, nor is it intended to dictate an exclusive course for the diagnosis, counseling, treatment or management of genetic conditions or birth defects. The authors acknowledge that appropriate clinical practices may vary depending upon a number of factors including, among others, the needs and choices of the individual patient, the resources available, and limitations unique to the particular institution or type of practice.

1. Review patient/family questions; reason for referral; knowledge base; perception of disease status and/or risk; what diagnoses have been considered; perceived notion of causation; assess need for professional interpreter: If patient is known to be symptomatic or disease status is unknown, follow appropriate critical elements for symptomatic or asymptomatic individual

2a. Using standard symbols, obtain family history (1st and 2nd degree relatives to consultand, and further removed as appropriate). Note ethnic background, consanguinity, ongoing pregnancies, and other significant family history.

b. Additional directed family history: neurological diseases, uncontrolled movements, mental illness, age of onset of symptoms, ages and causes of death.

c. Obtain relevant medical records on patient/affected family member(s), including records on appropriate diagnostic testing/evaluation: HD DNA testing, neurological exams, genetic evaluations

and on other family members as needed: as listed for patient, autopsy (brain)

3. Obtain patient's past and current pregnancy history; documenting gestational age, Rh, prenatal exposures, pregnancy complications and pertinent prenatal testing to date.

4. Obtain patient's past medical history: changes in mental and physical functioning, depression, traumatic head injury, drug and alcohol use.

5. Obtain information on education, employment and social functioning as appropriate: assess changes in job and driving performance, social/family functioning.

6. Assess family functioning and use of community resources, as appropriate. Assess personal (e.g. social, ethnocultural, religious) issues, including feelings about prenatal testing and consequences.

7. Assess ethical issues, such as confidentiality, insurability, discrimination and non-paternity.

8. Other issues to consider:

(this may occur in a series of multiple patient visits)

1a). Discuss risk of specific condition occurring in current pregnancy based on information available. Arrange for additional tests/evaluations on consultand and/or father of the baby if indicated: need to confirm the diagnosis of Huntington disease in one affected family member by HD DNA testing.

b). Discuss sensitivity/specificity of test(s)/evaluation(s):

c). Discuss referral of other family members for genetic testing/evaluation if inheritable disease is suspected and confirmation is necessary.

2a). Discuss general background risk for birth defects, including any additional risk based on family history/ethnicity/maternal age/maternal disease/maternal exposure/others:

b). Discuss inheritance pattern of disorder, including risk for future pregnancies:

3. Discuss the following issues related to natural history: prognosis, developmental outcome/intellectual functioning, anticipated possible medical complications, including pregnancy related risks for affected women if indicated, and preventive measures: positive HD DNA test result does not give information about age of onset of symptoms, severity of symptoms nor prognosis.

4a). Review prenatal testing options as indicated:

Testing a fetus at 25% risk by HD mutation analysis, which potentially may disclose the at risk parent's status, should be avoided. Refer to presymptomatic CE.

6. Document status of decision making by patient/family.

7. Make arrangements for testing if desired and plan for relaying results and for follow-up.

8. Consider referral to specific community resources and support groups.

10. Other issues to consider:

11. References and/or other protocols:

Hayden MR, Kremer B (1995). Huntington Disease in Scriver CR et. al., (eds), The Metabolic and Molecular Bases of Inherited Disease, NY:McGraw-Hill, Inc., p.4483-4510.