Differences in the determinants of right ventricular and regional left ventricular long-axis dysfunction in Friedreich ataxia

Abstract

Background Friedreich ataxia (FRDA) is an autosomal recessive neurodegenerative condition which also has effects on the heart. In 96% of affected individuals FRDA is due to homozygosity of a GAA repeat expansion in intron 1 of the frataxin (FXN) gene. The number of GAA repeats have been shown to relate to disease severity in FRDA, this thought to be via an inverse relationship of GAA repeat number and cellular frataxin levels. We investigated the effects of FRDA on regional long axis function of the left and right ventricles, and also the relationship of long axis systolic (s‘) and early diastolic (e‘) peak velocities with GAA repeat number on the shorter (GAA1) and longer FXN alleles (GAA2)..