How to diagnose Mitochondrial neurogastrointestinal encephalopathy syndrome ?
How might mitochondrial neurogastrointestinal encephalopathy syndrome be diagnosed? The clinical diagnosis of mitochondrial neurogastrointestinal encephalopathy syndrome (MNGIE) is based on the presence of severe gastrointestinal dysmotility (when the muscles and nerves of the digestive system do not move food through the digestive tract efficiently), cachexia (wasting away of muscle and fat tissue), ptosis, external ophthalmoplegia (weakness in the muscles that control eye movement), sensorimotor neuropathy, asymptomatic leukoencephalopathy (observed on brain MRI), and a family history consistent with autosomal recessive inheritance. Direct evidence of MNGIE syndrome can be provided by one of the following:  A blood test showing an increase in plasma thymidine concentration (greater than 3 mol/L) and an increase in plasma deoxyuridine concentration (greater than 5 mol/L). This is sufficient to make the diagnosis of MNGIE disease. Thymidine phosphorylase enzyme activity in leukocytes (white blood cells) less than 10% of the control mean. Genetic testing of TYMP, the gene for thymidine phosphorylase (the enzyme deficient in individuals with MNGIE syndrome), detects mutations in approximately all of affected individuals.