Clinicopathologic and molecular spectrum of <i>RNASEH1</i> -related mitochondrial disease

Abstract

In our cohort, <i>RNASEH1</i> mutations represent the fourth most common cause of adult mendelian PEO associated with multiple mtDNA deletions, following mutations in <i>POLG</i>, <i>RRM2B</i>, and <i>TWNK</i>. <i>RNASEH1</i> genetic analysis should also be considered in all patients with <i>POLG</i>-negative ataxia neuropathy spectrum. The pathophysiologic mechanisms by which the c.424G>A p.Val142Ile mutation impairs human RNase H1 warrant further investigation.