Topic 3 Family risk assessment; health promotion

Question 1

Answer 1

Male individual.

Question 2

Answer 2

Female individual.

Question 3

Answer 3

Individual - sex unknown.

Question 4

Answer 4

Affected individuals (symbol colored in).

Question 5

Answer 5

Deceased individuals.

Question 6

Answer 6

Miscarriage (third symbol - sex unknown).

No slash - spontaneous miscarriage.

*Slash - elective termination.*

Question 7

Answer 7

Pregnancy currently underway.

Question 8

Answer 8

Multiple individuals.

“N” is used when the number is unknown.

Question 9

Answer 9

Person providing pedigree information (proband).

Question 10

Answer 10

Marriage/partnership.

Question 11

Answer 11

Divorce/separation.

Question 12

Answer 12

Consanguineous relationship - partners are blood relatives.

Question 13

Answer 13

Children/siblings.

Question 14

Answer 14

Identical twins (monozygotic).

Question 15

Answer 15

Non-identical twins (dizygotic).

Question 16

Goals of a genetic family history assessment

Answer 16

1. Identify individuals and families at increased risk for inherited/familial conditions.
2. Offer appropriate health screening, genetic testing and/or interventions.
3. Offer genetic counseling and evaluation.
4. Educate or reassure.

Question 17

3 stages for collecting a family health assessment

Answer 17

1. Implement health history with genetic family *screening tool* (e.g., questionnaire) and analyze responses.
2. Collect additional information and analyze information.
3. Construct a pedigree, analyze the pedigree, and integrate into patient plan.

Global step: Refer to a genetic specialist, especially if red flags are present.

Question 18

Generations on a pedigree are labeled by _

Answer 18

Roman numerals on the left-hand side.

Question 19

Two horizontal lines beneath an individual on a pedigree indicates _

Answer 19

No children because of *infertility*.

Question 20

Answer 20

Autosomal dominant inheritance.

Question 21

Complex genetic traits

Answer 21

Those phenotypes not fitting patterns of Mendelian segregation and/or assortment but exhibiting a preferential familial clustering that cannot be explained by cultural or environmental causes.

Question 22

Common complex disorders

Answer 22

Asthma, allergies, diabetes, major depression and mood disorders, addiction, stroke and CVD, cancers: breast, ovarian, colorectal, prostate, lung.

Question 23

First degree relatives

Answer 23

Parents, siblings, children - proband shares 50% of their genetic material with these people.

Question 24

Second degree relatives

Answer 24

Half-siblings, aunts, uncles, grandparents, nieces and nephews - proband shares 25% of their genetic material with these people.

Question 25

Third degree relatives

Answer 25

First cousins - proband shares 12.5% of their genetic material with these people.

Question 26

Familial hyperlipidemia

Answer 26

1. *Autosomal dominant* - mutation in the LDL receptor gene on chromosome 19.
2. Cholesterol accumulates in the blood, leading to *coronary artery disease (CAD)*.
3. Phenotype: High cholesterol (300-400 mg/dL), xanthomas (fatty skin deposits over parts of the hands, elbows, knees, ankles, and around the cornea of the eye).
4. Heterozygous individual - by 40-60 years of age the person has an 85% chance of MI.
5. Homozygous individual - by 5-20 years of age the person has a high risk for MI.
6. Management: Statins, frequent CV screenings.

Question 27

Factor V Leiden thrombophilia

Answer 27

1. *Multifactorial inheritance* - mutation in combination with environmental factors.
2. Factor V fails to be properly inactivated by activated protein C, resulting in prolonged clotting, increased risk for DVT (especially with environmental factors), and increased risk for pregnancy loss.
3. Environmental factors: Oral contraceptives, estrogen therapy, stroke, trauma, surgery, pregnancy, or immobility.
4. Testing is especially important for *pregnancy* - risk for fetal loss, placental abruption, IUGR, stillbirth. Woman can be given phrophylactic heparin during pregnancy if she has the mutation.

Question 28

Which issue is considered a “red flag” for the need for referral to a genetics professional?

Answer 28

The presence of neurodevelopmental disorders in one or more members of the kindred. [Neurodevelopmental disorders and extreme presentations of common conditions are worth investigating by a genetics professional. Breast cancer, colon cancer, and myocardial infarction in the family history may require a genetics referral but usually only when they appear early.]

Question 29

How are Punnett Squares and pedigrees different?

Answer 29

Punnett Squares represent genotypes and pedigrees represent phenotypes. [Punnett Squares are diagrams that are used to determine the risk of offspring being affected when the mode of transmission and the parents’ carrier status are known. It is based on genotype. Pedigrees show relationships and expressed traits or disorders, the phenotype. Neither pedigrees nor Punnett Squares by themselves can identify actual carrier status. Pedigrees can suggest carrier status but not prove it. Punnett Squares require the genotypes for a specific trait be known for both parents to demonstrate probabilities.]

Question 30

Tay-Sachs disease and Gaucher disease are at least 10 times more common among _

Answer 30

People of Ashkenazi Jewish heritage (regardless of what religion they practice) than among non-Jews.

Question 31

Answer 31

Autosomal recessive inheritance.

Question 32

Answer 32

X-linked inheritance.

Question 33

Answer 33

Mitochondrial inheritance.

Question 34

“Average risk”

Answer 34

Individuals at average risk typically have no “red flags” in their family history, and no strong lifestyle or environmental factors that have a large influence on their risk. For these individuals, screening and management recommendations can be based on recommendations for the general population.

Question 35

“Moderate risk”

Answer 35

Individuals with one red flag and/or a lifestyle risk factor for a condition may be at moderate risk to develop that condition. For these individuals, you may want to consider more frequent screening and earlier or more intensive management.

Question 36

“High risk”

Answer 36

Individuals with more than one red flag and/or personal environment/lifestyle risk factors are considered to be at high risk for a condition. For these individuals, there are often published clinical guidelines for screening and management. In general, management of high-risk individuals includes earlier, more intense and frequent interventions, and possibly referral to a specialist.