We expected to create a severe phenotype similar to some of the available severe mouse models for GM2 gangliosidosis with HexA deficiency, i.e., SD (Hexb−/−) (Phaneuf et al., 1996) and double knockout TSD (Hexa−/-Neu3−/−) (Seyrantepe et al., 2018) models. The gene discussed is HEXA; the disease is GM2 gangliosidosis.