Saccade Velocity isControlled by PolyglutamineSize in SpinocerebellarAtaxia 2

ABSTRACT

We assessed maximal saccade velocity (MSV) in 82 spinocerebellarataxia type 2 (SCA2) patients and 80 controls,correlating it to disease duration, polyglutamine expansionsize, age at onset, ataxia score, age, and sex. Littleoverlap with normal values was found even at earlieststages. Stepwise linear regression analysis showed that 60-degree MSV was strongly influenced by polyglutaminesize and less by disease duration, whereas the reverse wasfound for ataxia score. Saccade velocity thus is a sensitive,quite specific, and objective endophenotype, useful tosearch polyglutamine modifier genes...(AU)