Familial childhood onset neuropathy and cirrhosis with the 4977bp mitochondrial DNA deletion.

The common 4977 base pair mitochondrial deletion has been identified in association with a number of distinct clinical phenotypes. These include the Kearns-Sayre syndrome, the Pearson marrow-pancreas syndrome, and chronic progressive external ophthalmoplegia. We report the clinical and pathological findings in two siblings in whom the 4977 base pair mitochondrial DNA deletion was identified in muscle-derived mitochondrial DNA. One sibling manifested early onset liver and renal failure, and both developed prominent peripheral sensorimotor neuropathy. These clinical findings have not been previously described in association with the 4977bp mtDNA deletion and thus represent a further expansion of the spectrum of mitochondrial disease.