Mitochondrial DNA Depletion Syndrome 6 / Navajo Neurohepatopathy (MPV17)
Mitochondrial DNA depletion syndrome 6 is an autosomal recessive disease caused by pathogenic variants in the gene MPV17. While it is a rare disease worldwide, a variant called Navajo neurohepatopathy has been identified in individuals of Navajo descent. Onset is during infancy, and clinical features include liver dysfunction and failure, developmental delay, failure to thrive, lactic acidosis and muscle weakness. Rarer symptoms include seizures, ataxia, and liver cancer. Navajo neurohepatopathy includes the above manifestations, as well as fractures, mutilation and autoamputation of the digits, and eye problems. While some patients are treated with liver transplants, many patients die in childhood or adolescence, regardless of transplantation. Homozygosity of a specific variant is associated with the Navajo neurohepatopathy variant.
For information about carrier frequency and residual risk, please see the Expanded Carrier Screen brochure.