CARRIER ERYTHROCYTE ENTRAPPED THYMIDINE PHOSPHORYLASE THERAPY FOR MNGIE

Mitochondrial neurogastrointestinal encephalomyopathy (MNGIE) is an autosomal recessive condition caused by mutations in the nuclear gene ECGF1 coding for thymidine phosphorylase (TP).1,2 Clinical features include gastrointestinal dysmotility, peripheral sensorimotor polyneuropathy, progressive external ophthalmoplegia, and hepatopathy. In vitro evidence and the improvement following stem cell transplantation (alloSCT) in one patient suggest the pathogenesis centers on elevated systemic levels of the TP substrates, thymidine (Thd) and deoxyuridine (dUrd).3,4 ### Case report. In September 2005, a 21-year-old woman presented after a 4-week history of progressive bilateral distal lower limb numbness and foot drop. She had bouts of unexplained gastrointestinal symptoms and weight loss since age 6 years and at 19 developed an acute abdomen leading to a laparotomy that revealed gross small bowel distension (thought to be caused by an elevated ligament of Treitz) and hepatosplenomegaly. A gastrojejunostomy was performed. On neurologic examination, the positive findings were subtle pigmentary retinopathy, partial ptosis, slight reduction of eye abduction, markedly slow horizontal saccades, severe weakness of ankle movements, absent muscle stretch reflexes and plantar reflexes, and stocking diminution for light touch and pain (all findings bilateral and symmetric). Of note on systemic examination: underweight, gross hepatosplenomegaly, tachycardia, and hyperdynamic cardiac apex. Her parents were not related. She left higher education in autumn 2005 due to her illness. After the laparotomy, investigations including hepatitis serology and serum copper were normal; a liver biopsy revealed steatohepatitis. A brain MRI was normal except equivocal diffuse high T2 signal in the centrum semiovale bilaterally. Following the initial presentation, abnormal results included normochromic normocytic anemia; serum lactate 3.72 mmol/L; CSF protein 1.95 g/L; CSF lactate 5.6 mmol/L; plasma Thd 13 μmol/L and …