Our results using minocycline indicate that it is a poor PARP1 inhibitor and was ineffective in reducing basal ADP-ribosylation in ARH3-deficient cells.<h4>Discussion</h4>This study contributes to the growing body of knowledge on ARH3 deficiency associated with CONDSIAS, by identifying a new pathogenic variant and questioning the molecular rationale underlying the therapeutic use of minocycline in patients with CONDSIAS. Here, PARP1 is linked to neurodegeneration, childhood-onset, stress-induced, with variable ataxia and seizures.