Blogs

• Some traits like intelligence, physical ability and longevity are genetically determined but the effect of external and environmental influences are the main determinants of health and survival
• With increased control of environment, genetic makeup is becoming more important determinant of individual health
• Genetic predisposition may lead to the premature onset of common diseases of adult life such as
– Cancer
– Coronary heart disease
– Diabetes
– Hypertension and
– Mental disorders
• Cancer:

• This occurs:
– If the fetus is Rh positive and
– mother is Rh negative

• Some fetal red cells cross the placenta and enter maternal circulation in all pregnancies
– The Rh +ve fetal cells act as foreign antigen and stimulate production of Rh antibodies in the Rh negative mother

• The Rh antibodies are of two main types:
– The ‘strong’ or saline antibodies and
– The ‘weak’ or albumin antibodies: these are small 7s gamma globulins which can cross the placental barrier.

It is the introduction of a gene sequence into a cell with the aim of modifying the cell’s behaviour in a clinically relevant fashion

It may be used in several ways, e.g.
o To correct a genetic mutation (as for cystic fibrosis),
o To kill a cell (as for cancer) or
o To modify susceptibility (as for coronary artery disease)

Prenatal diagnosis or screening is testing for diseases or conditions in a fetus or embryo before it is born
Such diseases include Thalassaemia, Sickle cell anaemia, cystic fibrosis, haemophilia, fragile X syndrome, Neural tube defects, birth defects etc.

New-borns deserve the special protection afforded by screening for disorders where early diagnosis and treatment favourably affect outcome.

Following guidelines are recommended by W.H.O for neonatal screening:

It is the most immediate and practical service that genetics can render in medicine and surgery
Counselling should include a full description of the risks, diagnosis, symptoms, and treatment of the disorder(s) in question

• “Euthenics" is “improvement in the environment.”
• Mere improvement of the genotype is of no use unless the improved genotype is given access to a suitable environment which will enable the genes to express themselves readily
• Thus the solution of improving the human race does not lie in contrasting heredity and environment but rather in the mutual interaction of heredity and environment factors
• This environmental manipulation is called euthenics and has considerable broader prospects for success

“Euphenics” means the improvement of the phenotype by biological means.
Euphenics involves the incorporation of the advances in
• Molecular biology,
• Immunology, neurophysiology, and
• Other rapidly growing biological fields
Into medical practice for management of genetic diseases and their prevention
Euphenics has been advocated as “a corrective measure for our genetic ills.”

Defined as the science which aims to improve the genetic endowment of human population
Eugenics is directed against whole populations and in present times, is considered to be associated with coercive policy
Hence today, it has a negative connotation.
Eugenics has two different fields, negative eugenics and positive eugenics

Series of charts/posters
Each with an illustration pertaining to the topic
Shown one after another
Each chart is ‘flashed’ before the group
Designed to hold the attention of the group

Reference:
Park’s Textbook of Preventive and Social Medicine, 23rd ed