TK2d

Inside each of our cells are mitochondria, or the powerhouses of the cell. Their job is to make the energy the body needs to function properly, including actions like lifting your arms or inflating your lungs with each breath. This energy is referred to as adenosine triphosphate, or ATP. To make ATP, mitochondria need enzymes, a type of protein. When there is an error, or mutation in the DNA that code for the enzyme or protein, the mutation can cause a mitochondrial disease. One type of mitochondrial disease is thymidine kinase 2 deficiency, or TK2d. TK2d is a very rare inherited genetic disease that results in an enzyme deficiency that affects mitochondrial DNA (mtDNA). With TK2d, less mtDNA is being made, which means muscles don’t have enough energy and cannot function right. Symptoms of TK2d include muscle weakness (myopathy), difficulty breathing, droopy or saggy eyelids, trouble chewing and swallowing or fatigue. TK2d can present in infants, children or adults.