Page 1 of 101
NUR 240 EXAM 1
Genetics
• Genetics: Study of Inheritance
• Study of individual genes and their impact on relatively rare single gene disorders
• DNA – giant cookbook with recipes for all the proteins, hormones, and enzymes
• Chromosome pairs are the different book chapters- so it has 23 chapters
• Genes- individual recipes contained within the chapters
• So the purpose of a gene is to serve as the instructions for making a specific protein.
Mutations can change the activity of a protein and have adverse effects on health
• Genes are located in the nucleus of most body cells. The cell nucleus contains the DNA in
the form of chromosomes. All cells contain all the genes. For example, you make insulin in
the beta cells of the pancreas. But all human cells with a nucleus have the gene for insulin.
The only cell type that allows the insulin gene to be active and make insulin is the beta cell
of the pancreas. So only in the beta cells is this gene selectively turned on or expressed
when you need to make insulin.
• So all human cells with a nucleus each contain the entire set of human genes. This
complete set of genes is called a genome. Mature RBCs and sex cells- eggs and sperm do
not have a nucleus.
• DNA, chromosomes, and genes are all the same basic thing, only the structure differs.
• Genetic Mutations
• Mutations are DNA changes that are passed from one generation to another and thus are
inherited. Genes for most proteins are the same in all people but sometimes a base in one
person’s gene for a specific protein is not the same and can be a mutation. The difference
allows the protein to be made but there are differences in how well it works- this causes a
loss of protein function
• THE BIG DOG ATE THE CAT
• THE BIG DOG ATE THE CAP
• THB IGD OGA TET HEC AT
• THE PBI GDO GAT ETH ECA T
• Mendelian Inheritance Patterns
• Most common gene alterations that result in genetic disorders are categorized into
Mendelian inheritance patterns, because they are predictably passed on from generation to
generation following Mendel’s laws of inheritance
, Page 2 of 101
• Autosomal dominant
• Autosomal recessive
• Sex-linked (x-linked) recessive
• Autosomal Dominant
• Both males and females affected
• Males and females usually affected in equal numbers
• Affected child will have an affected parent and/or all generations will have an affected
individual
• Unaffected children of an affected parent will have unaffected children
• Examples: breast and ovarian cancer, Marfan syndrome, polycystic kidney disease
• Autosomal Recessive
• Both males and females affected
• Males and females usually affected in equal numbers
• Affected child will have an unaffected parent but may have affected siblings (condition may
appear to skip a generation)
• Parents of the affected child may be close blood relatives
• Family may be descendants of a certain ethnic group that is known to have a more frequent
occurrence of a certain genetic condition
• Examples: cystic fibrosis, phenylketonuria, sickle cell anemia
• X-Linked Recessive
• More males affected than females; rarely seen in females
• An affected male will have all carrier daughters
• There is no male-to-male inheritance
• Affected males are related by carrier females
• Females may report varying milder symptoms of the condition
• Examples: hemophilia A, color blindness, duchenne muscular dystrophy
• X-linked Dominant exist but are rare
• Multifactoral Inherited Conditions
• Combination of genetic and environmental factors
• Diabetes mellitus, obesity, HTN, cancer, and coronary artery disease
• Types of Genetic Testing
• Includes any procedure done to analyze chromosomes, genes, or gene products that can
determine a mutation or a predisposition to a condition
• Newborn screening- newborns checked for phenylketonuria, sickle cell disease
• Carrier testing
, Page 3 of 101
• completed on asymptomatic persons who may be carriers of one copy of a gene
alteration that can be transmitted to future children in autosomal recessive or X-linked
pattern.
• Chromosomal diagnostic exam
• Blood sample and skin or buccal cell sampling
• DNA-based tests
• Blood, bone marrow, amniotic fluid, cells of skin, or buccal cells from mouth
• Benefits of Genetic Testing
• Provide for:
• Early screening and preventive measures
• Future planning and life preparation
• Lifestyle adaptations
• Decreased confusion and anxiety
• Psychologic stress relief
• Reproductive choices
• Informed extended family members
• Early medical and/or surgical intervention
• Cost of medical follow-up reduced (if negative result)
• Nursing Responsibility
• Alert client of their right to make an informed decision before testing
• All testing should be voluntary
• Discuss benefits and risks prior to testing
• Informed consent
• Results should only be given to person who gave consent
• Do not give information to government, employment, or insurance agencies, even extended
family members without written permission
• Healthcare providers are legally liable to maintain confidentiality
• Should have pretest and posttest counseling by genetic specialists or healthcare provider
• See table 12-4 page 185
• Other Issues: Genetic Testing
• Psychosocial issues:
• Social stigmatization
• Survivor guilt
• Positive test result may lead to feelings of unworthiness, confusion, anger, depression,
and issues with self-image
• Economic issues
, Page 4 of 101
• Can be very expensive
• Most insurances will not cover
• No treatment may exist
• Employability affected
• Assessment: Genetic Testing
• If a patient inherits mutations in BRCA1 and BRCA2 genes, they have increased risk for
• breast cancer in men or women
• prostate cancer in men
• If mutations in MLH1 or MSH2 gene, have increased risk for
• colorectal cancer
• Family history (to see medical history and inheritance possibilities)
• Should include 3 generations
• Figure on page 182, And Punnett Square on 189 figure 12-9
• Assessment: Genetic Testing
• Referral is made to genetic clinical nurse, genetic counselor, and/or physician if
• The disease or disorder occurs at a higher incidence within the family than among the
general population.
• The client or close family members have another identified genetic problem.
• The incidence of a specific disease or disorder occurs in the client or in family members
at an unusually early age.
• A rare disease is present in two or more family members.
• More than one type of cancer is present in any one person.
• The presence of clinical manifestations is associated with one or more genetic disorders.
• Nursing Diagnoses
• Anticipatory Grieving
• Anxiety
• Disturbed Body Image
• Ineffective Coping
• Decisional Conflict
• Interrupted Family Processes
• Ineffective Health Maintenance
• Deficient knowledge
• Powerlessness
• Spiritual Distress
• Evaluation
• Expected outcomes
NUR 240 EXAM 1
Genetics
• Genetics: Study of Inheritance
• Study of individual genes and their impact on relatively rare single gene disorders
• DNA – giant cookbook with recipes for all the proteins, hormones, and enzymes
• Chromosome pairs are the different book chapters- so it has 23 chapters
• Genes- individual recipes contained within the chapters
• So the purpose of a gene is to serve as the instructions for making a specific protein.
Mutations can change the activity of a protein and have adverse effects on health
• Genes are located in the nucleus of most body cells. The cell nucleus contains the DNA in
the form of chromosomes. All cells contain all the genes. For example, you make insulin in
the beta cells of the pancreas. But all human cells with a nucleus have the gene for insulin.
The only cell type that allows the insulin gene to be active and make insulin is the beta cell
of the pancreas. So only in the beta cells is this gene selectively turned on or expressed
when you need to make insulin.
• So all human cells with a nucleus each contain the entire set of human genes. This
complete set of genes is called a genome. Mature RBCs and sex cells- eggs and sperm do
not have a nucleus.
• DNA, chromosomes, and genes are all the same basic thing, only the structure differs.
• Genetic Mutations
• Mutations are DNA changes that are passed from one generation to another and thus are
inherited. Genes for most proteins are the same in all people but sometimes a base in one
person’s gene for a specific protein is not the same and can be a mutation. The difference
allows the protein to be made but there are differences in how well it works- this causes a
loss of protein function
• THE BIG DOG ATE THE CAT
• THE BIG DOG ATE THE CAP
• THB IGD OGA TET HEC AT
• THE PBI GDO GAT ETH ECA T
• Mendelian Inheritance Patterns
• Most common gene alterations that result in genetic disorders are categorized into
Mendelian inheritance patterns, because they are predictably passed on from generation to
generation following Mendel’s laws of inheritance
, Page 2 of 101
• Autosomal dominant
• Autosomal recessive
• Sex-linked (x-linked) recessive
• Autosomal Dominant
• Both males and females affected
• Males and females usually affected in equal numbers
• Affected child will have an affected parent and/or all generations will have an affected
individual
• Unaffected children of an affected parent will have unaffected children
• Examples: breast and ovarian cancer, Marfan syndrome, polycystic kidney disease
• Autosomal Recessive
• Both males and females affected
• Males and females usually affected in equal numbers
• Affected child will have an unaffected parent but may have affected siblings (condition may
appear to skip a generation)
• Parents of the affected child may be close blood relatives
• Family may be descendants of a certain ethnic group that is known to have a more frequent
occurrence of a certain genetic condition
• Examples: cystic fibrosis, phenylketonuria, sickle cell anemia
• X-Linked Recessive
• More males affected than females; rarely seen in females
• An affected male will have all carrier daughters
• There is no male-to-male inheritance
• Affected males are related by carrier females
• Females may report varying milder symptoms of the condition
• Examples: hemophilia A, color blindness, duchenne muscular dystrophy
• X-linked Dominant exist but are rare
• Multifactoral Inherited Conditions
• Combination of genetic and environmental factors
• Diabetes mellitus, obesity, HTN, cancer, and coronary artery disease
• Types of Genetic Testing
• Includes any procedure done to analyze chromosomes, genes, or gene products that can
determine a mutation or a predisposition to a condition
• Newborn screening- newborns checked for phenylketonuria, sickle cell disease
• Carrier testing
, Page 3 of 101
• completed on asymptomatic persons who may be carriers of one copy of a gene
alteration that can be transmitted to future children in autosomal recessive or X-linked
pattern.
• Chromosomal diagnostic exam
• Blood sample and skin or buccal cell sampling
• DNA-based tests
• Blood, bone marrow, amniotic fluid, cells of skin, or buccal cells from mouth
• Benefits of Genetic Testing
• Provide for:
• Early screening and preventive measures
• Future planning and life preparation
• Lifestyle adaptations
• Decreased confusion and anxiety
• Psychologic stress relief
• Reproductive choices
• Informed extended family members
• Early medical and/or surgical intervention
• Cost of medical follow-up reduced (if negative result)
• Nursing Responsibility
• Alert client of their right to make an informed decision before testing
• All testing should be voluntary
• Discuss benefits and risks prior to testing
• Informed consent
• Results should only be given to person who gave consent
• Do not give information to government, employment, or insurance agencies, even extended
family members without written permission
• Healthcare providers are legally liable to maintain confidentiality
• Should have pretest and posttest counseling by genetic specialists or healthcare provider
• See table 12-4 page 185
• Other Issues: Genetic Testing
• Psychosocial issues:
• Social stigmatization
• Survivor guilt
• Positive test result may lead to feelings of unworthiness, confusion, anger, depression,
and issues with self-image
• Economic issues
, Page 4 of 101
• Can be very expensive
• Most insurances will not cover
• No treatment may exist
• Employability affected
• Assessment: Genetic Testing
• If a patient inherits mutations in BRCA1 and BRCA2 genes, they have increased risk for
• breast cancer in men or women
• prostate cancer in men
• If mutations in MLH1 or MSH2 gene, have increased risk for
• colorectal cancer
• Family history (to see medical history and inheritance possibilities)
• Should include 3 generations
• Figure on page 182, And Punnett Square on 189 figure 12-9
• Assessment: Genetic Testing
• Referral is made to genetic clinical nurse, genetic counselor, and/or physician if
• The disease or disorder occurs at a higher incidence within the family than among the
general population.
• The client or close family members have another identified genetic problem.
• The incidence of a specific disease or disorder occurs in the client or in family members
at an unusually early age.
• A rare disease is present in two or more family members.
• More than one type of cancer is present in any one person.
• The presence of clinical manifestations is associated with one or more genetic disorders.
• Nursing Diagnoses
• Anticipatory Grieving
• Anxiety
• Disturbed Body Image
• Ineffective Coping
• Decisional Conflict
• Interrupted Family Processes
• Ineffective Health Maintenance
• Deficient knowledge
• Powerlessness
• Spiritual Distress
• Evaluation
• Expected outcomes
