Citations

Abstract Study Objectives Narcolepsy is a chronic condition affecting the sleep/wake cycle that is challenging to diagnose. Epidemiological data from large US-focused studies remain limited, with no validated claims-based case selection definitions for narcolepsy. We estimated the prevalence/incidence of diagnosed narcolepsy (type 1 [NT1], type 2 [NT2], overall) in an insured US population using validated, claims-based narcolepsy case definitions. Materials and Methods This observational study used HealthVerity administrative claims-linked electronic medical records to develop case definitions identifying individuals with NT1, NT2, and overall narcolepsy from diagnosis, medication, and procedure codes. Claims-based case definition performance (NT1, NT2, overall narcolepsy) was assessed using positive predictive values (PPVs). Prevalence (per 100 000 persons, on December 31, 2023) and annual incidence (per 100 000 person-years [PY], 2020 − 2023) were calculated/adjusted using PPVs for each case definition. Results Unadjusted point prevalence among individuals with ≥12 months of continuous enrollment were 15.5/100 000 (NT1), 51.1/100 000 (NT2), and 67.0/100 000 (overall narcolepsy). Unadjusted incidence rates were stable from 2020 − 2023 for NT1 (range, 2.0 − 2.3/100 000 PY) but declined across years for NT2 (9.1 − 7.6/100 000 PY) and overall narcolepsy (11.3 − 9.6/100 000 PY). PPVs (95% confidence interval) of NT1, NT2, and overall narcolepsy were 0.81 (0.72 − 0.88), 0.84 (0.75 − 0.91), and 0.80 (0.71 − 0.87), contributing to epidemiologic estimates being reduced by ~20% after PPV adjustment. Prevalence and incidence were higher in females than males. Individuals with NT1 were ~ 4 years younger versus NT2. Conclusions Validated definitions for narcolepsy can reduce potential misclassification. Our findings highlight a relatively low NT1 prevalence in the US. In contrast, NT2 prevalence estimates were > 3 times higher than NT1.

COASY-related disorders (CRDs) are a spectrum of autosomal recessive conditions caused by the dysfunction of CoA synthase, an enzyme responsible for the final steps of CoA synthesis. Clinical manifestations of CRDs are highly variable, ranging from perinatal lethal pontocerebellar hypoplasia to childhood-onset neurodegenerative brain iron accumulation, which is often recognized after clinical regression. Recent reports have described a few individuals with CRD who screened positive for carnitine palmitoyltransferase-I deficiency by newborn screening (NBS). However, heterogeneous clinical presentations, conflicting biochemical/molecular sequencing of CPT1A, and a lack of metabolic characterization have led to lengthy, costly diagnostic journeys. To address some of these aspects, this investigation retrospectively evaluated NBS acylcarnitine patterns in five CRD cases using Collaborative Laboratory Integrated Reports (CLIR). A total of 25 metabolites/ratios were identified to deviate significantly from reference ranges and were primarily composed of elevated free carnitine and reduced long-chain acylcarnitine levels. While low acylcarnitine concentrations are often not reported due to a lack of lower reference cutoffs, ratios involving these metabolites relative to short-chain acylcarnitines could aid in identifying CRD cases via NBS. When comparing this pattern to CPT-Ia cases, we confirmed a nearly identical acylcarnitine pattern between these, and thus support the need to consider CRD in cases with NBS results suggestive of CPT-Ia. This study is the first case series to characterize NBS patterns in patients with CRD and highlights the unique opportunity for early detection, particularly in cases that are neonatally asymptomatic and have unremarkable confirmatory biochemical results.