We would like to draw attention to a recent discovery that may explain the striking discordance between the clinical and biochemical phenotypes observed in Schindler disease. This disorder was originally reported in siblings with deficiency of α-N-acetylgalactosaminidase (α-NAGA) and early-onset, rapidly progressive psychomotor regression.¹ Whereas α-NAGA deficiency underlies the abnormal oligosacchariduria found in Schindler disease, its causal role in the neurological phenotype has been questioned. Other patients with α-NAGA deficiency show a puzzling spectrum of clinical findings that range from angiokeratoma to …