In a child with a clinical presentation suggestive of CLN2, including neuropsychomotor regression, epilepsy, and ataxia, enzymatic and molecular tests should be requested, and there is no consensus in our panel concerning which molecular test should be performed first (either search for the pathogenic variant of the CLN2 gene or new generation sequencing/epileptic encephalopathies panel). This evidence concerns the gene TPP1 and epilepsy.