Marriage between two heterozygous individuals for the same disorder is prevented by:

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