This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Hospital waste and disaster management, Occupational health, Subject name: Social & Preventive Medicine
Marriage between two heterozygous individuals for the same disorder is prevented by: 
Select and explain. 
A. Retrospective genetic counselling, B. Prospective genetic counselling, C. Legislation, D. Mass health education
B: Prospective genetic counselling
Answer: B: Prospective genetic counselling 
Explanation: GENETIC COUNSELLING: Prospective genetic counselling: Identify heterozygous individuals for any paicular defect (through screening) and explaining to them risk if having affected children if they marry another heterozygous for same gene Useful in sickle cell anemia, Thalassemia Retrospective genetic counselling: Seeking genetic advice after hereditary disorder has already occured in the family. useful in: Congenital anomalies, Mental retardation, Psychiatric illness, Inborn errrors of metabolism Ref: Park 25th edition Pgno: 865