The DGUOK gene provides instructions for making the enzyme deoxyguanosine kinase. This enzyme plays a critical role in mitochondria, which are structures within cells that convert the energy from food into a form that cells can use. Mitochondria each contain a small amount of DNA, known as mitochondrial DNA or mtDNA, which is essential for the normal function of these structures. Deoxyguanosine kinase is involved in producing and maintaining the building blocks of mitochondrial DNA.
Approximately 40 mutations in the DGUOK gene have been identified in people with deoxyguanosine kinase deficiency. Some of these mutations change single protein building blocks (amino acids) in the deoxyguanosine kinase enzyme. Other mutations result in an abnormally shortened, nonfunctional enzyme or cause the enzyme to be pieced together incorrectly.
Mutations in the DGUOK gene reduce or eliminate the activity of the deoxyguanosine kinase enzyme. Reduced enzyme activity leads to problems with the production and maintenance of mitochondrial DNA. A reduction in the amount of mitochondrial DNA (known as mitochondrial DNA depletion) impairs mitochondrial function in many of the body's cells and tissues. These problems lead to the neurological and liver dysfunction associated with deoxyguanosine kinase deficiency.
- deoxyguanosine kinase isoform a precursor
- deoxyguanosine kinase isoform b precursor
- deoxyguanosine kinase, mitochondrial