Genetics

Question 1

What is the primary goal of the Human Genome Project?

Answer 1

To produce a map of every gene that comprises the human genome

This project aims to lead to interventions that can prevent or treat conditions with a genetic component.

Question 2

What are the current prenatal testing options available?

Answer 2

• Maternal serum screening
• Alpha fetoprotein
• Percutaneous umbilical blood sampling
• Fetal nuchal translucency (FNT)
• Fetal ultrasound level 2
• Triple and quad screening tests
• Amniocentesis
• Chorionic villus sampling

These tests help assess fetal health and genetic conditions.

Question 3

What does predictive testing clarify?

Answer 3

The genetic status of asymptomatic family members

An example includes mutation analysis for Huntington’s disease.

Question 4

What are the primary risks associated with genetic testing?

Answer 4

• High false positives
• Anxiety
• Altered family relationships
• Discrimination and stigmatization
• Gap between testing and treatment
• Denial of insurance benefits
• Ethnic and socioeconomic disparity

Question 5

True or false: Autosomal dominant inheritance requires two copies of an abnormal gene for the disease to develop.

Answer 5

FALSE

Only one abnormal gene from either parent is needed for autosomal dominant inheritance.

Question 6

What are examples of autosomal recessive disorders?

Answer 6

• Sickle Cell Anemia
• Cystic Fibrosis
• Tay-Sachs Disease

Individuals with one defective gene are carriers and can pass it on. If the child receives two defective genes, they will be symptomatic

Question 7

What is the characteristic of X-linked recessive disorders?

Answer 7

Defective gene located on the X chromosome, affecting mainly males, since they only carry one X chromosome

Examples include Hemophilia and color blindness.

Question 8

What is the role of genetic counseling?

Answer 8

• Provides genetics information
• Offers education
• Provides support

Question 9

What are the key roles for nurses in genetics?

Answer 9

• Identification of families needing genetic counseling
• Providing emotional support
• Awareness of responses to testing
• Managing ethical, legal, and social issues

Question 10

What is Gene Therapy?

Answer 10

• Corrects genes responsible for disease development
• Involves inserting a healthy copy of the defective gene into the somatic cells
• Currently in clinical studies (for diseases like hemophilia to cancer)

Question 11

What is the single most cost-effective piece of genetic information?

Answer 11

Family history

Question 12

What information does a fetal ultrasound give?

Answer 12

• Fetal heart activity
• Gestational age
• Fetal growth
• Fetal anatomy
• Fetal genetic disorders and anomalies
• Placental position and function
• Fetal well being

Question 13

What should we know about amniocentesis?

Answer 13

• Obtains amniotic fluid to assess fetal cells
• Can be done after 14 weeks
• Use of ultrasound guided needle

Question 14

What should we know about chorionic villus sampling?

Answer 14

• Earlier diagnosis and rapid results
• Used in 1st trimester (10-13 weeks)
• Removal of small tissue specimen from fetal portion of the placenta
• Reveals genetic information of fetus
• Can be done transcervically or transabdominally, US guided

Question 15

What is pre-dispositional testing?

Answer 15

• Positive result does not indicate 100% risk of developing condition
• Example: BRCA 1 gene

Question 16

What does multifactorial inheritance mean?

Answer 16

• A combination of genetic and environmental factors determine condition
• Examples: cleft palate & lip, congenital heart disease, neural tube defects, pyloric stenosis

Question 17

What are the chances of inheriting an autosomal dominant disorder if one parent as a dominant gene defect?

Answer 17

50% chance

Question 18

What are some examples of autosomal dominant disorders?

Answer 18

• Neurofibromatosis
• Huntington’s Disease
• Factor V Leiden
• Marfan syndrome
• Dwarfism
• Mytonic dystrophy

Question 19

What is the risk of inheriting a autosomal recessive disorder with two carrier parents?

Answer 19

25% with each pregnancy

Question 20

What is Tay-Sachs Disease?

Answer 20

• Fatal genetic lipid storage disease
• Common in Jews and French Canadians
• Appear normal at birth, but fatal by 3-4 years of age
• No treatment
• Nerve cells become distended with fatty material
• Deterioration of mental and physical abilities

Question 21

What is an X-Linked Dominant disorder?

Answer 21

• Abnormal gene from one parent capable of causing disease
• Gene located on X chromosome
• Risk of transmission from affected parent = 50% with each pregnancy
• Examples: Vitamin D resistant Rickets, Rett syndrome

Question 22

What are common characteristics of Down’s Syndrome?

Answer 22

• Upward slant of eyes
• Flat facial profile
• Depressed nasal bridge, small nose
• Protruding tongue
• Small, low set ears
• Short broad hands
• Hyperflexibility
• Low muscle tone