Disease name: Polymerase gamma-related diseases, called POLG-related diseases for short
Affected populations: POLG-related diseases are a group of rare, incurable conditions caused by inherited gene mutations. These disease-causing mutations are carried
by up to 2% of people of Northern European descent. However, not everyone who carries the mutations ultimately develops a POLG-related disorder.
Estimates suggest that these diseases affect approximately 1 in 10,000 people worldwide.
Causes: POLG-related diseases are caused by several hundred different mutations in the
POLG gene. This gene encodes a protein in mitochondria, called
DNA polymerase gamma (pol γ), which is needed to replicate and repair the unique
DNA found only inside mitochondria, rather than in the cell nucleus.
People develop POLG-related diseases by inheriting either
one or two copies of the mutated POLG gene from one or both of their parents.
Mitochondria are the cellular powerhouses responsible for
breaking down the carbohydrates and fatty acids in food to produce molecules called ATP, which the body then uses as energy.
In people with POLG-related diseases, issues with polymerase gamma can either end up decreasing the amount of DNA in mitochondria or introducing mutations into that DNA. And in some cases, both these events can occur.
