Transcript UNIT I: INTRODUCTION

Basic Components of Human
Genetics
INTRODUCTION
What is Genetics?
 Genetics –
 It is the branch of biological sciences which deals with the
transmission of characters from parents to offspring.
 The term genetics was coined by Bateson in 1906. It has been
derived from the Greek word ‘gene’.
 (gene= ‘to become’)
 Genes –
 set of characteristics inherited from your parents
 Found on chromosomes and contain DNA
Heredity
 The transfer of character or traits from the parents to
offspring.
Variations
 The similarities and differences between the character
or traits among the individuals of the same species.
IMPLICATIONS OF GENETICS TO
HUMAN WELL-BEING
 Knowledge of genetics is helpful in understanding the causation
of diseases.
 It also helps us to understand how normal variation between
individuals are brought about.
 Knowledge of genetics has also led to possible means of
prevention of genetic disorders through genetic counseling and
antenatal diagnosis.
 Genetics serves to solve even legal problems. Legal cases
involving disputed parentage may be sorted out by an analysis of
blood groups or other inherited characteristics.
RELATIONSHIP TO OTHER SCIENCES
Genetics in relation to other sciences
Cytogenetics
Biochemical
Radiation
Eugenetics
Genetics
Clinical
Developmental
Physiological
Immunogenetics
1. Cytogenetics
 A branch of genetics that is concerned with the study of the
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structure and function of the cell, especially the chromosomes.
This discipline is concerned with the cytologic and molecular
bases of genetics.
Example: Down syndrome (trisomy 21)
Patau Syndrome (trisomy 13)
Edward Syndrome (trisomy 18)
Chronic Myelogenous Leukemia (has a small chromosomes in
WBC)
2. Biochemical Genetics
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the study of fundamental relationships between genes,
protein, and metabolism.
This involves the study of the cause of many heritable
diseases.
Example:
SICKLE CELL ANEMIA and THALASSEMIA
PHENYLKETONURIA and GALACTOSEMIA
3. Developmental Genetics
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The branch of science of development which attempts to
understand the role of genes in development.
the process that gives rise to tissues, organs and anatomy.
It is a process which brings about various changes in
fertilized egg to make it into a complete adult.
4. Physiological Genetics
- This branch of genetics involves the use of knowledge of
physiology to elucidate the effects produced by genetic
factors on an individual.
- relationship of hereditary diseases and genetics
5. Immunogenetics
- It is a branch of science which is concerned with the
genetic aspects of immunity mechanisms.
6. Clinical Genetics
- It is a branch of genetics which helps to establish the
causative factors responsible for certain disease like Diabetes
Mellitus, Haemophilia etc.
7. Radiation Genetics
- This branch of genetics involves the study of effects of
various radiation on genes.
8. Eugenics- “eu” means “good/well”
genes means born
- It is a branch of science which deals with the application of
principles of heredity to the improvement of mankind.
- Francis Galton defined eugenics as the study of all agencies
under human control which can improve or impair the racial
quality of future generations.
2 Categories of Eugenics
1. Positive Eugenics
 Aimed at encouraging reproduction among the genetically
advantaged
 Example: the reproduction of the intelligent, the healthy
and the successful
 Approaches:
 Financial and political stimuli
 Targeted demographic analysis
 In vitrofertilization
 Egg transplants
 cloning
2. Negative Eugenics
 Aimed to eliminate through sterilization or
segregation
 Physically, mentally or morally undesirable
 Approaches:
 Abortions
 Sterilization
 Or other methods of family planning
Human Genome Project
The Human Genome Project formally began in
1990 and was completed in 2003
What is Human Genome Project?
 Is an international scientific research project
 The Project was coordinated by the National Institutes of
Health and the U.S. Department of Energy.
 Additional contributors included universities across the
United States and international partners in the United
Kingdom, France, Germany, Japan, and China.
 It is a collaborative venture to identify and mark all the
locations of every genome of the human species.
 In US, the HGP was started at 1990 and was expected to be a
fifteen year effort to map the human genome.
 2003 the project accelerated its progress
 Hopes to discover 50,000- 100,000 human genes and make
them available for further biologic study.
Goals of Human Genome Project
 Determine the entire sequence of human DNA (3,000,000,000
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bases in the haploid human genome)
Identify all the genes in human DNA approximately 35,000
genes.
Store this information in databases
Improve tools for data analysis
Transfer related technologies to the private sector
Address the ethical, legal, and social issues (ELSI) that may
arise from the project.
What is DNA sequencing?
 Sequencing means determining the
exact order of the base pairs in a
segment of DNA.
 Map-based (gene mapping) or BAC-
based (bacterial-artificial chromosome)is a method used by the HGP to
produce the finished version of the
human genetic code
Benefits of HGP
1. In the field of molecular medicine
 Better diagnosis of disease,
 Early detection of certain diseases
 Gene therapy and control systems of drugs
 In the future there should be new treatments in molecular
medicine that don’t treat the symptoms but look at the causes
of the problem at hand.
Benefits of HGP
2. In the field of microbial genomics
 They may be able to find new energy sources, through the
sequencing of a bacterial genome.
 This could lead to discoveries that are useful in energy
production, toxic waste reduction, and industrial processing.
Benefits of HGP
3. Can be very useful for the understanding of human
evolution and human migration.
- it may help lead scientists to find out how humans evolved
and how humans are evolving today.
4. It will help to understand the common biology that
we share with life on earth. Comparing our genome
with others may help to lead to associations of diseases with
certain traits.
Benefits of HGP
5. In the field of agriculture and livestock breeding
- this technology could help to develop disease, insect, and
drought resistant crops thus being able to produce more for
the world.
- it also help to produce healthier, more productive, and
possibly disease resistant animals to be sent to market.
Disadvantages of Human Genome
Project
 Research cost is high
 People are afraid of discrimination of genes
 People don’t support gene therapy because it’s “against
nature”
Ethical, Legal, and Social Issues
 Fairness in the use of genetic information by insurers,
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employers, courts, schools, adoption agencies, and the military,
among others.
Psychological impact, stigmatization, and discrimination
based on genetic differences/ disorders.
Privacy and confidentiality of genetic information
Reproductive issues including adequate and informed consent
and use of genetic information in reproductive decision making
Clinical issues including the education of doctors and other
health-service providers, people identified with genetic conditions,
and the general public about capabilities, limitations, and social
risks; and implementation of standards and quality-control
measures.
PREDICTIONS FOR THE
NEXT TEN YEARS
1.
Science Will Pinpoint What Makes Us Homo
Sapiens
In the near future, scientists will be able to compare our genome
against those of our evolutionary cousins, such as chimpanzees
and Neanderthals, to get a clearer sense of which genes are
involved in making us Homo sapiens
2. Gene Therapy will cure diseases
Gene therapy—curing ailments by replacing faulty
copies of genes with normal ones—will finally become a
reality, likely within the next decade.
3. Personal Genomes Will Spawn Made-to-Measure
Drugs
• Thanks to improving technology, within the next five years a
person should be able to have his or her entire genome
sequenced for about a thousand U.S. dollars, many experts
say.
4. Personality Will Move From Art to
Science
 As scientists learn to better understand the information
contained in our genomes, they will get better at predicting
how genes influence the development of physical and mental
traits and even behaviors.
Role of the Nurse in
Genetics
 Take detailed family history
 Construct Pedigrees
 Assess hereditary and non hereditary risk factors
related to genetic diseases, or diseases with a
genetic component
 Provide genetic information to individuals and
families
 Interpret genetic tests and laboratory data
 Manage and care for patients and families at risk for or
affected by genetic diseases or diseases with a genetic
component.
 Provide genetic counseling, genetic consultation, and
case management for persons with complex genetic
health care needs.
THANK YOU!