Genetics/Leukemia - Blood Cancer.
Dear Prof Natarajan
Is Leukemia - Blood Cancer a hereditary or genetic Disease?.
Leukemia mostly is not a hereditary disorder. Exposure to radiation, environmental chemicals, industry solvents and compounds like benzene can predispose a person to acquire certain mutations in the genes, leading to leukemia. These mutations are not present at birth, but at some point in life, blood forming cells acquire this mutation due to some life-style (smoking, alcohol,etc) habits or exposure to cancer causing substances.
Hereditary conditions that can lead to leukemia:
There are hereditary conditions that can put a person at a higher risk for leukemia. You might be knowing about Down syndrome.This is a congenital (at birth) condition with 3 copies of chromosome 21. These individuals are likely to develop leukemia. There are other genetic conditions where a person may be born with a mutation - which means that mutation is in all cells of his/her body. The person will be normal in all respect but when exposed to certain chemicals or radiations, will have less or no power to combat cancer-causing mutations.. By combat, what I mean is that all of use are bombarded by cancer-causing agents at some point or other in our life. But our body repair mechanisms will be able to fix it and we won't develop cancer. But people born with certain mutations at birth, will not be able to repair it because of a deficiency in their repair mechanism of DNA/genes. These people belong to a condition called Li-Fraumeni syndrome. They have a mutation in a gene called TP53 which is protector or guardian which protects the body from cancer. With age, it might decline, and hence older people have a higher risk. But people with TP53 mutation can get any cancer in their 20s, 30s, etc in any part of the body, not just leukemia. OTher such mutations are know in other genes that can lead to leukemia.
So to summarize, leukemia can arise from hereditary conditions, as well as without any hereditary cause.