[5][6][7] This gene encodes a member of the histidine triad (HIT) superfamily, some of which have nucleotide-binding and diadenosine polyphosphate hydrolase activities.

[7] Aprataxin removes AMP from DNA ends following abortive ligation attempts by DNA Ligase IV during non-homologous end joining, thereby permitting subsequent attempts at ligation.

[8][9] Ataxia oculomotor apraxia-1 is a neurological disorder caused by mutations in the APTX gene that encodes aprataxin.

[11] The SOD1 mutation causes a reduction in transcription recovery following oxidative stress.

This study also demonstrated a protective role of Aptx in vivo and suggested that the loss of Aptx function results in progressive accumulation of DNA breaks in the nervous system, triggering hallmarks of systemic premature aging [11] (see DNA damage theory of aging).