ch. 3 genetics

Question 1

genetics

Answer 1

study of a particular gene

Question 2

genomics

Answer 2

study of all genes in the entire genome

Question 3

genes

Answer 3

physical units of heritance

Question 4

genome

Answer 4

entire set of genetic instructions found in a cell

Question 5

epigenetics

Answer 5

focuses on genetic changes not due to any underlying change in DNA sequence
- covid vaccine: sends message to mRNA to fight virus

Question 6

precision medicine (or health)

Answer 6

disease prevention/health promotion
- helps HCP discover individual client’s disease risks & treatments best for them
- cancer treatment

Question 7

nursing expertise in genetics and genomics

Answer 7

1) essential competencies for all nurses
- all nurses need to have minimal competencies to genetics and genomics regardless of their academic preparation, practice setting, and specialty

2) expanded roles for nurses with expertise in genetics and genomics are developing in many areas of maternity and women’s health nursing

Question 8

examples of current perinatal testing options

Answer 8

1) preimplantation testing: involves couples seeking care for infertility

2) cell free fetal DNA screening: blood test performed at 8-9 weeks
- more available to all pregnant women

3) prenatal microarray testing: performed on cells from CVS or amniocentesis. detects extra or missing genetic information (copy variants) (looking at direct fetal cells for both sources)

4) whole exome sequencing: looks at all protein coding genes

5) whole genome sequencing: sequences an organism’s entire genome at one time

Question 9

human genome project: implications for clinical practice

Answer 9

1) key findings: all human being are 99.9% identical at the DNA level

2) ENCODE project: organized to identify the genome’s functional elements

Question 10

human genome project: implications for clinical practice (importance of family history)

Answer 10

1) completion of the human genome project has resulted in renewed interest in family history

2) single most cost effective piece of genetic information

3) US department of health and human services has designated Thanksgiving as “national family history day”

4) many family history tools are available online

Question 11

human genome project: implications for clinical practice (gene identification)

Answer 11

1) gene identification and testing:
- valuable resource: genetic testing registry
- many kinds of genetic testing
- rapid development of prenatal testing options

2) gene identification and testing:
- predictive testing: presymptomatic testing, predispositional testing

Question 12

human genome project: implications for clinical practice (population based screening)

Answer 12

1) newborn screening

2) carrier screening for single-gene disorders:
- cystic fibrosis
- sickle cell disease
- tay sach’s disease

3) expanded carrier screening now encourages

Question 13

human genome project: implications for clinical practice (pharm)

Answer 13

1) pharmocogenomic (PGx) testing:
- performed to examine an individual’s genes to determine how medications are absorbed, move through the body, and are metabolized by the body

2) gene therapy:
- aim is to correct defective genes that are responsible for disease development
- inserting a healthy copy of the defective gene into somatic cells of the affected individuals

Question 14

human genome project: implications for clinical practice (ethical, legal, and social implications (ELSIs)

Answer 14

1) privacy and fairness in use and interpretation of genetic information

2) clinical integration of new genetics technologies

3) ethical issues including the process of informed consent

4) education for professionals and general public about genetics and the complex issue that result from genomic research

Question 15

human genome project: implications for clinical practice (factors influencing the decision to undergo genetic testing)

Answer 15

1) decision often based on feelings of responsibility and commitment to others

2) cultural and ethnic differences

3) raises fundamental questions about the mutual obligations of kin

Question 16

clinical genetics: genetic transmission

Answer 16

1) human development is a complicated process; it depends on systematically unraveling genetic material

2) development from conception to birth usually occurs without incident

3) birth defects occur in 1 of every 33 babies born in the US

Question 17

clinical genetics: genes and chromosomes

Answer 17

1) DNA -> chromosomes -> genes

2) homologous: 23 matched chromosomes

3) autosomes: 22 pairs

4) sex chromosomes: 1 pair, XX or XY
- loci
- alleles: homozygous, heterozygous

Question 18

clinical genetics: genes and chromosomes

Answer 18

1) genotype:
- the genetic makeup of a specific gene pair, or sometimes used to refer to an individual’s entire genetic makeup

2) phenotype:
- the observable expression of an individual’s genotype
- ex: brown hair, olive skin

3) dominant

4) recessive

5) karyotype:
- pictorial analysis of nucleic form and size of an individual’s chromosomes
- ex: missing genes, size of individual chromosomes

Question 19

clinical genetics: abnormalities

Answer 19

1) chromosomal abnormalities:

2) autosomal abnormalities

3) abnormalities of chromosome number:
- euploid cell: correct number of chromosomes
- poluploidy (extra)
- aneuploidy (absent)
- monosomy (one): union between a normal gamete and one that is missing a chromosome
- trisomy: (21 - down’s, 18 - edward syndrome, 13 - patau syndrome)
- nondisjunction: failure of chromosomes to separate normally

Question 20

clinical genetics: chromosomal abnormalities

Answer 20

autosomal abnormalities

1) abnormalities of chromosome structure
2) translocation: robertsonian
3) reciprocal: balanced, unbalanced
4) deletion: terminal deletion, interstitial deletion, microdeletion
5) inversion
6) sex chromosome abnormalities
7) turner syndrome: monosomy X female
8) klinefelter syndrome: trisomy XXY male

Question 21

clinical genetics: patterns of genetic transmission

Answer 21

1) multifactorial inheritance

2) unifactorial inheritance
(a) autosomal dominant inheritance
- ex: neurofibromatosis (NF), factor V leiden (FVL), mardan syndrome, myotonic dystrophy
(b) autosomal recessive inheritance (sickle cell)
(c) inborn errors of metabolism
(d) X linked dominant inheritance
(e) X linked recessive inheritance
- fragile X

Question 22

cancer genomics

Answer 22

1) gene mutations that can lead to cancer

2) three main ways that people acquire gene mutations that can lead to cancer:
- environmental factors (pesticides)
- acquire by chance
- inherited (breast cancer)

3) two main types of genes that play a critical role in the development of cancer:
- oncogenes
- tumor suppressor genes

4) hereditary breast and ovarian cancer
- BRCA 1/ BRCA 2

5) colorectal cancer: two examples of predisposing genes
- APC tumor suppressor gene
- mutations in two MMR genes (i.e. MLH1 or MLH2) result in hereditary nonpolyposis colon cancer (HNPCC) (Lynch syndrome)

Question 23

genetic counseling

Answer 23

1) definition of genetic counseling

2) access and referral to genetic counseling

3) estimation of risk

4) interpretation of risk

5) multiple roles for nurses in genetic counseling
- identify families in need of genetic counseling
- make referrals to specialists
- provide information about genetics
- provide emotional support

Question 24

future promise of genetics

Answer 24

• remarkable advances made through the human genome project
• increased availability of genetic testing and other genetic services
• awareness of genetic risk can facilitate informed health care
• advances in molecular biology
• ability to offer diagnostic, preventative, and treatment options not only for genetic diseases, but also for common diseases (eg. cancer, atheroscleorosis, diabetes, alzheimer disease)

Question 25

what best describes the pattern of genetic transmission known as autosomal recessive inheritance?

Answer 25

disorders in which both genes of a pair must be abnormal for the disorder to be expressed