Sialidosis type 1 was genetically confirmed by the findings of two variants in the NEU1 gene: c.649G>A (p.V217M), a previously reported pathogenic variant, and c.644T>C (p.L215P), a variant never previously reported in patients with sialidosis type 1 and not found in large databases of unaffected subjects (ExAC/gnomAD, dbSNP). The gene discussed is NEU1; the disease is sialidosis type 1.