A mitochondrial defect is responsible for a type of human hereditary deafness that worsens over time and can lead to profound hearing loss. Using a genetically-modified mice model with a mitochondrial dysfunction that results in a similar premature hearing loss, researchers showed that precise genetic reduction of an enzyme, AMP kinase (AMPK), can rescue the hearing loss. Their results are reported in the American Journal of Pathology.

"Mitochondrial dysfunction causes human diseases, with an estimated occurrence of 1 in 5,000 to 10,000 live births. Mitochondrial diseases are complicated and heterogeneous, characterized by cell- and tissue-specific responses and pathology. An extreme example of tissue specificity is the A1555G mitochondrial DNA (mtDNA) mutation that causes maternally-inherited deafness," explained lead investigator Gerald S. Shadel, PhD, of the Departments of Pathology and Genetics at Yale School of Medicine.

Researchers caution that additional work is needed before the results from this mouse model are used to inform pathology in maternally inherited deafness caused by mtDNA mutations in humans and to understand how these mice might shed light on prophylactic or therapeutic strategies.