 Ocular symptoms may include retinal degeneration, ophthalmoplegia, and ptosis.Those with MNGIE are often thin and experience continuous weight loss.The characteristic thinness of MNGIE patients is caused by multiple factors including inadequate caloric intake due to gastrointestinal symptoms and discomfort, malabsorption of food from bacterial overgrowth due to decreased motility, as well as an increased metabolic demand due to inefficient production of ATP by the mitochondria.