TYMP

thymidine phosphorylase

Normal Function

Health Conditions Related to Genetic Changes

Mitochondrial neurogastrointestinal encephalopathy disease

About 50 variants (also called mutations) in the TYMP gene have been identified in people with mitochondrial neurogastrointestinal encephalopathy (MNGIE) disease. This condition affects several parts of the body, particularly the digestive system and nervous system.  

TYMP gene variants greatly reduce or eliminate the activity of thymidine phosphorylase. A shortage of this enzyme allows thymidine to build up to very high levels in the body. This extra thymidine can damage mtDNA, disrupting its usual maintenance and repair processes. As a result, variants can accumulate in mtDNA, causing it to become unstable. In people with MNGIE disease, mitochondria may also have less mtDNA than usual (mtDNA depletion). These genetic changes impair the normal function of mitochondria. Although mtDNA abnormalities underlie the digestive and neurological problems that are characteristic of MNGIE disease, it is unclear how defective mitochondria cause the specific features of the disorder.

More About This Health Condition

Related Conditions

Mitochondrial neurogastrointestinal encephalopathy disease

Health Conditions Related to Genetic Changes

About 50 variants (also called mutations) in the TYMP gene have been identified in people with mitochondrial neurogastrointestinal encephalopathy (MNGIE) disease. This condition affects several parts of the body, particularly the digestive system and nervous system.  

TYMP gene variants greatly reduce or eliminate the activity of thymidine phosphorylase. A shortage of this enzyme allows thymidine to build up to very high levels in the body. This extra thymidine can damage mtDNA, disrupting its usual maintenance and repair processes. As a result, variants can accumulate in mtDNA, causing it to become unstable. In people with MNGIE disease, mitochondria may also have less mtDNA than usual (mtDNA depletion). These genetic changes impair the normal function of mitochondria. Although mtDNA abnormalities underlie the digestive and neurological problems that are characteristic of MNGIE disease, it is unclear how defective mitochondria cause the specific features of the disorder.