A cluster of microvillous inclusion disease in the Navajo population

We report 4 unrelated patients with characteristic microscopic findings of microvillous inclusion disease (MID) with early-onset phenotype. All 4 pati ents came from the Navajo reservation in northern Arizona. A literature sea rch revealed a fifth unrelated Navajo child with MID. The unusually high in cidence in this population indicates that a founder effect might be respons ible for an increased frequency of this rare genetic disorder in the Navajo . It is recommended that all Navajo infants presenting with severe diarrhea during early infancy undergo investigation for MID.