HCRT and hyperinsulinemic hypoglycemia, familial, 4: 2025). By definition, individuals with NT2 do not experience cataplexy and have normal or unmeasured hypocretin levels in their CSF (Bassetti et al. 2019). Diagnosis of NT2 is largely one of exclusion, as no specific biomarkers have been identified (Son et al. 2021). Current research suggests that NT2 may represent a spectrum of disorders, possibly including cases with partial hypocretin deficiency that do not meet the threshold for NT1 or dysfunction in downstream hypocretin signaling pathways (Huth et al. 2024).