Made by- Preeti Karn Para – H2

Roll no.- 89

Role of community medicine in control of

genetic diseases

Health of an individual is based on

Uncontrollable factors (genetics, gender, predisposition to a disease).

Controllable factors (diet, smoking status, exercise levels).

Over the last few decades, a significant transition has taken place in the etiology of diseases affecting mankind.

Environmentally related disorders have decreased and genetic disorders and non communicable disorders have become a major cause of morbidity and mortality.

GENETICSStudy of inheritance dealing with the

transmission of hereditary characters from one generation to another.

Human genetics is concerned with the inheritance of human traits and their relationship to the human health.

Deals with the hereditary disorders and provide key to their prevention and control.

Prevalence of Genetic DisordersPrevalence of genetic disorders

(excluding multifactorial genetic disease)- 7/1000 live births.

Out of 7, - 4 sex linked disorders. - 2 Autosomal disorders. - other characterized by balanced or unbalanced chromosomal rearrangements.

Genetic Disorders

Diseases Associated with Genetic PredispositionCancer

Coronary heart disease

Diabetes (Insulin dependent)

Alzheimer’s disease

Biological Determinant Genetics Predisposition to disease

A person may be at increased risk of inheriting a disease or condition if they have a biological parent who has had the disease.

Genetics can have an influence on a persons risk to certain conditions or diseases.

Ex. If your parent has high cholesterol, you are at a higher risk of developing high cholesterol.

Examples of diseases- genetic predisposition Alzheimer’s disease (before the age of 65)

Migraine headaches Type 1 and 2 diabetes CVD – High blood pressure, hypertension Certain cancers – (including breast and prostate)

Prevention & Control of Genetic Disorders

1. Prevention

2. Screening

3. Counseling

Specific ProtectionFrom X-Ray Early diagnosis by :- - Detection of carriers - Prenatal diagnostics - Amniocentesis - New born screening - Pre clinical case recognition

Screening

Applied at Prenatal, Neonatal & general population levels.

Prenatal & Neonatal screening – ideal approach for early diagnosis & prompt treatment of hereditary disorders.

Prenatal ScreeningPrenatal screening by:- - Ultrasonography - Amniocentesis(14-16 weeks of pregnancy) diagnosis of spina bifida & other neural tube abnormalities. - Chorionic villus sampling technique(10-12 weeks of pregnancy)- both biochemical and structural abnormalities can be detected.

Neonatal Screening

Help in detecting hereditary disorders like:-

- Phenylketonuria - Sickle cell Anemia - Duchenne muscular dystrophy

Population Screening To identify individuals at risk of developing

hereditary disorders. Objective :- -To make presymptomatic diagnosis for arresting the progress of such disease by timely preventive intervention.

- Only such disorders should be Identified for which measures for prevention & treatment are available.

Genetic counseling :- An integral part of management of patients and families with genetic disorders.

- Retrospective

- Prospective

Genetic Counseling

Essential Components of Counseling History of family background constructionClinical diagnosis Confirmatory diagnosisCalculation reoccurrence Counseling Follow up

Reaching accurate diagnosis Family history Physical/Clinical examination

Cytogenetic studies/Radiology Laboratory/DNA analysis

Estimation of recurrence risk:- - Family pedigree - Applying various methods - Risk calculation - Bayesian - Mendels

Genetic Counseling :- - Available options - Risk calculation - New developments - Disease course - Treatment availability

Decision Making :- - Knowledge of disease recurrence - Available options - Family pressure - Religious beliefs - Social status - Economic status - Community influence

Gene Therapy

Means introduction of gene sequence into

cell with aim of modifying the cell behavior in a clinically relevant fashion.

Used in many ways :-To correct genetic mutation To kill a cell To modify susceptibility The gene may be introduced using a virus or by means of a lipid or receptor targeting.

Eugenics Idea of hereditary improvement by selective breeding propagated

by Galton. Can be defined as improvement of human species or race by

selective breeding. Positive Eugenics :- - Applied to animals for increasing milk and have better quality animals - Improving yield of grains - Genetic manipulation for human welfare and survival. Negative Eugenics :- - Example – Purify german race by eliminating genetically poor individuals.

Euthenics

Means providing appropriate / suitable environment for genotype to express themselves fully.

Measures to improve the environment in order to improve health, appearance, behavior, or well being or society.

Lead an independent existence.

Genetic Services MTP PC-PNDT act Antenatal clinics Immunization ContraceptionIron and folic acid supplement USG ICDS programme

REFERENCES

Park’s Textbook of Preventive and Social Medicine

www.wikipedia.com

www.emedicine.medscape.com