The Navajo are uniquely affected by a rare and life-threatening autosomal recessive multisystem disorder called Navajo Neurohepatopathology (NNH), a genetic condition estimated to occur in 1 of every 1,600 live births. The most severe symptoms include neuropathy and liver dysfunction (hepatopathy), both of which may be moderate and progressive or severe and fatal, as it often is in cases that develop in infants (before 6 months of age) or children (1-5 years). Other symptoms include corneal anesthesia and scarring, acral mutilation, cerebral leukoencephalopathy, failure to thrive, and recurrent metabolic acidosis with intercurrent infections.