Genetics of Blood Stem Cells

Genetics of Blood Cells

What are blood cells?

Stem cells are cells that can become many other types of cells.  These include:

• Muscle cells
• Heart cells
• Nerve cells
• Blood cells

Blood cells include red blood cells, white blood cells, and platelets.  Red blood cells carry oxygen to the rest of your body.  White blood cells help fight infections.  If you are bleeding, platelets help your blood to clot.  We have a good balance of each type of cell in our blood stream.

If a gene change happens in a stem cell, then that cell can pass the change on to the cells it creates.

What is a gene change?

Genes are segments of DNA.  We have 2 copies of most genes–one from each parent.  Genes are instructions. Sometimes the instructions might read a little different. This difference is a mutation or gene change. Most changes are harmless.  But some may raise our risk for problems or cause disease.

You can be born with gene changes. They can also happen after we are born.  Those changes only happen in the cell affected.  Examples include:

• Radiation from the sun can cause gene changes in skin cells.
• Smoking can cause gene changes in lung cells.
• Harmful chemicals can also cause gene changes.

Gene changes also occur as we age.

Sometimes, a gene change can give one cell an advantage over other cells.  When this happens with blood stem cells, the stem cells make one type of blood cell more than the others.  The term for this is clonal hematopoiesis, or CH for short.

What is clonal hematopoiesis of indeterminant potential (CHIP)?

“Clonal” means clone, or a group of all the same cell type.  For example, red blood cells.  “Hema” or “hemato” means blood.  “Poiesis” means forming.  So, CH occurs when a stem cell makes one type of blood cell more than the others.  CH of indeterminate potential (CHIP) is caused by gene changes. The gene changes are not yet dangerous. People with CHIP may feel healthy.  But, CHIP can raise your risk for blood cancers or heart disease. It is rare in people under 30, but about 1 in 10 elderly people have it.

Scientists at Vanderbilt University Medical Center want to learn more about CHIP.  They want to find out what causes the disease and what are the effects.  They will use BioVU to compare the genes of patients with and without CHIP.  They will look for gene changes linked to CHIP.

The results may help us learn more about which gene changes cause CHIP.  If we know more about the cause, we can work to develop new treatments.  We also might learn who might be at risk for CHIP.  That may help us look for ways to slow it down or even prevent it.