Chapter 5: Genetics and genomics perspectives in nursing

1. Chapter 5:Genetics and genomics perspectives in nursing

2. Integrating genetics and genomics perspectives in nursing • Genomics: study of human genome, including gene sequencing, mapping, function • Nurses must understand new technologies, treatments of genetic-, genomic-based healthcare • Nurses must recognise they are vital link between patient, healthcare services • May be person patient turns to first for questions, information • Nurses must recognise, deal appropriately with ethical issues that may arise related to genetics

3. Awareness of attitudes, experiences and assumptions • Beliefs or values about health • Family, religious or cultural beliefs about cause of illness; how one’s values or biases affect understanding of genetic conditions • Philosophical, theological, cultural, ethical perspectives related to health • How these perspectives influence one’s use of genetics information or services • Level of expertise about genetics, genomics

4. Awareness of attitudes, experiences and assumptions (cont’d) • Experiences with birth defects, chronic illnesses, genetic conditions along with one’s view of such conditions as disabling or empowering • Attitudes about right to access, other rights of individuals with genetic disorders • View, assumptions about DNA, beliefs about value of information about one’s risk for genetic disorders • Beliefs about reproductive options • View of genetic testing, engineering • Approach to patients with disabilities

5. Five main tasks • Help collect, interpret relevant family, medical histories • Identify patients, families who need further genetics evaluation and counselling, refer them to appropriate genetics services • Offer genetics information, resources to patients, families • Collaborate with genetics specialists • Participate in management, coordination of care of patients with genetic conditions

6. Nursing genetics and genomics assessment • Family history • Physical • Ancestry, cultural, social, spiritual • Psychosocial

7. Question Is the following statement true or false? • Genomics is the study of the human genome, including gene sequencing, mapping and function

8. Answer • True • Rationale: Genomics is the study of the human genome (DNA in the chromosomes and in the mitochondria), including mapping of genes and sequencing of the DNA

9. Genetics family history • Assess risk of certain diseases • Decide on testing strategies (what genetic, other diagnostic tests to order) • Establish pattern of inheritance • Identify other family members at increased risk • Identify shared environmental risk factors • Calculate risks

10. Genetics family history (cont.) • Assess risk of passing on conditions to children • Determine, recommend treatments that modify disease risk • Make decisions about management or surveillance • Develop patient rapport • Educate patients

11. Genetic counselling: Professional practice • Providing pre-counselling information • Preparing patients for genetics evaluation • Communicating genetic, genomic information to patients • Providing support

12. Genetic concepts • Most health conditions now thought to be combination of genetic, environmental influences • Human Genome Project: international research effort aimed at identifying, characterising order of every base in human genome • Genotype: genes, variations that person inherits from parents • Phenotype: person’s entire physical, biochemical, physiologic makeup as determined by person’s genotype, environmental factors

13. Terms • Chromosome: microscopic structures in cell nucleus that contain genetic information, constant in number in a species • Cell division: • Mitosis • Meiosis • Gene mutations: heritable alteration in genetic material • Genetic variation: variation in degree to which trait is manifested; clinical severity

14. Question Is the following statement true or false? • Meiosis is cell division that occurs in somatic cells that normally result in daughter cells with the same number of chromosomes

15. Answer • False • Rationale: Mitosis is cell division that occurs in somatic cells that normally result in daughter cells with the same number of chromosomes. Meiosis is the reduction division of diploid egg or sperm resulting in haploid gametes

16. Deoxyribonucleic acid (DNA) • Primary genetic material in humans consisting of nitrogenous bases, sugar group, phosphate • Combined into double helix

17. Inheritance patterns • Autosomal dominant: affects female, male family members equally • Follows vertical pattern of inheritance in families • Autosomal recessive: pattern is more horizontal than vertical • Relatives of single generation tend to have condition • X-linked: inherited in recessive or dominant patterns

18. Autosomal dominant • Variable expression • Penetrance • Examples: • BRCA1 breast cancer gene • Retinoblastoma • Huntington’s disease

19. Autosomal recessive • More frequently seen among particular ethnic groups, more likely in children of parents related by blood • ‘Carriers’ • Examples: • Cystic fibrosis • Sickle cell anaemia • Tay-Sachs disease

20. X-linked inheritance • May be recessive or dominant • Gene located on X chromosome • Since males have only one X chromosome, inherited disorder (if recessive) seen in all males who have gene • If recessive, females with one affected gene are carriers • Have 50/50 chance of passing disorder to son • Examples • Factor VII, Factor IX haemophilia • Duchenne’s muscular dystrophy

21. Multifactorial inheritance and complex genetic conditions • Many common health conditions result from interactions of multiple genes, environment • Conditions may cluster in families but do not follow characteristic patterns of inheritance

22. Chromosomal differences • Chromosomal differences: major cause of birth defects, mental retardation, malignancies • Extra or missing chromosome or structural rearrangement of chromosome • Examples • Down syndrome • Turner’s syndrome

23. Genetic testing and screening • Genetic testing: primary tool used to identify individuals predisposed to specific genetic diseases • Genetic screening: applies to testing of populations or groups independent of positive family history or symptom manifestation

24. Ethical issues • Respect patient’s right to self-determination, autonomy • Right to privacy, confidentiality