Myoneurogastrointestinal Encephalopathy (TYMP)

Myoneurogastrointestinal encephalopathy is an autosomal recessive disorder caused by pathogenic variants in the gene TYMP. While this disease has been reported in patients of different ethnicities, a founder effect has been identified in the Sephardic Jewish population from Iran. Onset of symptoms is usually in adolescence or early adulthood; some patients do not show symptoms until middle age. Clinical features include progressive gastrointestinal dysmotility, which is associated with weight loss, pain and distension of the abdomen, reflux and difficulty eating. Weakness of the eye muscles develops, resulting in eyelid drooping and difficulty moves the eyes. Pain and tingling of the lower extremities, as well as muscle weakness, can also occur. Progressive worsening of the symptoms results in a shortened life expectancy; the average age of death is 38 years. No genotype-phenotype correlation has been reported, and therefore the age of onset and the severity of the disease cannot be predicted based on genotype.

For information about carrier frequency and residual risk, please see the residual risk table.