2. INTRODUCTION:
• During mid 19th century, Gregor Mendel observed that certain
features pass from parents to their children / offspring.
• A child usually looks like their parents and is due to inheritance of
certain characteristics from parents to children .
• This transmission of characteristics from parents to children is known
as heredity.
• The basic unit of heredity is gene ,which consist of portion of DNA
molecules.
• The term gene was coined by Johannsen in 1909.
3. GENETICS:
• Genetics is the study which deals with the science of genes , heredity
and it variations in living organism.
• Gregor Mendel is the father of genetics .
• The term genetics was coined by William Bateson .
5. GENE:
• Gene is defined as a segment of DNA (Deoxyribonucleic acid) which
carries the genetic information.
• Gene is the basic physical and functional unit of heredity.
• DNA has also segment which do not contain gene.
• The human genome contains about 30000 – 40000 genes and each
gene varies in size.
7. ROLE OF NURSE IN GENETICS:
• Nurses came across individuals or families affected by the genetic
diseases.
• Nurses are a vital links between patients and health care services.
• Nurses should have a basics sound knowledge of genetics.
8. GENETIC COUNSELING AND INTERVIEWING
• Interviewing patients or individuals with suspected genetic disorders
• Taking a detailed clinical history along with relevant family history
(over three generations ) from patients of child with genetic disorder.
• Refer those with genetic disorder to the concerned doctors .
9. PLANNING, SCREENING OR GENE BASED
TESTING PROGRAMS
• Provide health education related to genetics and genetic testing
• Drawing and interpreting a pedigree chart.
• Ability to recognize the possibility of a genetic disorder based on the
pedigree chart.
• Assessment of a genetic risk especially in conjugation with genetic
testing options.
10. MONITORING:
• Follow up of positive new born screening test
• Monitoring individuals with genetics disorders
• Working with families under stress due to a genetic disorder.
11. CARE:
• Developing an individualized plan of care and services of affected
patient.
• Participating in public education about genetics.
• Maintain the privacy and confidentiality of the patients genetics
information.
12. EDUCATIONAL ROLE :
• GENETIC ASPECT:
When a genetic condition is identified , it leads to stress and shock in the
individuals and his family.
The nurses have a major role in counselling , reducing their fears ,getting
the consent for genetics testing and arranging the test and offering post
test advice.
• ABOUT TRANSMISSION OF GENETIC CONDITION WITHIN FAMILIES:
If an individual is identified to have a genetic condition, nurses should
educate the family members , who are likely to affected and advice
counselling and screening for them.
13. EDUCATION ROLE :
• Educate how genetics and environmental factors influence health and
disease.
• Nurse should be able to identify the mendelian patterns of
inheritance of genetic conditions in families in the form of a
pedigree(family tree)
14. IMPACT OF GENETICS :
IMPACT OF
GENETIC
CONDITIONS
ON FAMILIES
SOCIAL IMPACT
(culture ,altered
family process)
PSYCHOLOGICAL
IMPACT
ECONOMIC IMPACT
(tests , interventions,
employment)
PHYSICAL
COGNITIVE
IMPACT
15. IMPACT OF GENETIC CONDITIONS ON
FAMILIES:
• GUILT – parents with genetic disorder tend to feel guilty, when they
come to know that might have passed on a condition to a child .
• DEPRESSION – when an individual comes to know that he/she has a
genetic condition and the decision to terminate a pregnancy , may
result in depression or loss of peace of mind.
17. CELL DIVISION:
• Genetic information is passed from parents to all descendent cells
through cell division mitosis.
• There are two cell division-
1. Mitosis (somatic cell division )
2. Meiosis (germ cell division)
18. CELL DIVISION:
• In normal tissues, molecules such as hormones , growth factors and
cytokines provide the signal to activate the cell cycle ;
• A controlled programme of biochemical events that culminates in cell
division .
• In all cells of the body , except the gametes (the sperm and egg cells,
also known as the germ line ), mitosis completes cell division ,
resulting in two diploid daughter cells .
• In contrast , the sperm and eggs cell complete cell division with
meiosis, resulting in four haploid daughter cells.
19.
20. STAGES:
• The stages of cell division in the non-germ line ,somatic cells are
shown below:
• Cells not committed to mitosis are said to be in G0.
• Cells committed to mitosis must go through the preparatory phase of
interphase consisting of G1, S & G2.
21. G0 (RESTING PHASE):
• The term “post – mitotic ” is sometimes used to refer to both
quiescent and declining cells.
• Non proliferative cells is multicellular eukaryotes generally enter
quiescent G0 state from G1 and may remain quiescent for long
periods of time.
22. CELL CYCLE
• G1(FIRST GAP):
synthesis of the cellular components necessary to
complete cell division.
23. S (SYNTHESIS):
• DNA replication producing identical copies of each chromosome
called the sister chromatids .
24. G2 (SECOND GAP):
• Repair of any errors in the replicated DNA before proceeding to
mitosis.
25.
26.
27. MITOSIS (M):
• Mitosis consist of four phase ;
1.PROPHASE: the chromosomes condense and become visible , the
centrioles move to opposite ends of the cell and the nuclear membrane
disappears.
28. 2.METAPHASE:
• The centrioles complete their migration to opposite ends of the cell
and the chromosomes - consisting of two identical sister chromatids
- line up at the equator of the cell .
30. TELOPHASE:
• The chromosomes decondense ,the nuclear membrane reforms and
two daughter cells – each with 46 chromosomes – are formed
31.
32. • The progression from one phase to the next is tightly controlled by
cell – cycle checkpoints. For eg: the check point between G2 and
mitosis ensures that all damaged DNA is repaired prior to
segregation of the chromosomes.
• Failure of these control processes is a crucial driver in the
pathogenesis of cancer
