Ataxin-2 contains the following protein domains:[7] A potential transcript variant, missing an internal coding exon, has been described; however, its full-length nature is not certain.

Longer expansions can cause spinocerebellar ataxia type 2 (SCA2), a fatal progressive genetic disorder in which neurons degenerate in the cerebellum, inferior olive, pons, and other areas.

Symptoms of SCA2 include ataxia (a loss of coordinated movements), parkinsonism, and dementia in some cases.

In 2010, work from Aaron Gitler and Nancy Bonini at the University of Pennsylvania discovered that intermediate-size CAG repeat expansions are significantly associated with risk for developing amyotrophic lateral sclerosis (Lou Gehrig's disease).

Further investigation of the genetic and biological mechanisms underlying the association between ATXN2 and POAG could provide valuable insights into the pathogenesis and potential therapeutic targets for glaucoma.