To overcome these challenges, we first generated the iNgly1 mouse model on a C57BL/6 background that showed 80%–90% reduction in Ngly1 expression, concomitant with disease phenotype that recapitulated human NGLY1 deficiency, including elevated GNA, failure to thrive, loss of Purkinje cells, motor impairment, and kyphosis. Here, NGLY1 is linked to Failure to thrive.