Hereditary intestinal neurofibromatosis. I. A distinctive genetic disease.

Intestinal neurofibromatosis without other manifestations of von Recklinghausen's neurofibromatosis was found in a multigeneration family. Neurofibromas were strictly limited to the intestine. Onset of symptoms was delayed until adulthood and some gene carriers remained asymptomatic into their middle or late adult years. One other family with intestinal neurofibromatosis has been described in 1966. No symptomatic male is yet known, although an asymptomatic male in our family is an obligate gene carrier. The gene for intestinal neurofibromatosis may be incompletely penetrant and its expression varies even in symptomatic patients. No male-to-male transmission has been recorded to rule out X linkage. Intestinal neurofibromatosis presents as a distinctive dominant phenotype with an increased risk of intestinal problems including bleeding, intussusception and obstruction.