| Study / disorder context | Publication date | Cohort size | Key quantitative findings | DOI / URL | Citation |
|---|---|---:|---|---|---|
| International Niemann-Pick Disease Registry (INPDR), Niemann-Pick disease type C (NPC) | Feb 2022 | N=203 NPC patients from 6 countries | Mean age at diagnosis 11.2 years; neurological-onset distribution: early infantile 24.2%, late infantile 26.4%, juvenile 23.0%, adult 20.8%, neonatal rapidly fatal systemic form 5.6%; among 97 with identified NPC1 variants, p.I1061T/c.3182T>C in 35.1% (abstract) and reported as 28.6% in extracted registry summary; splenomegaly was the most commonly reported observation and was recorded in 80% of adult patients; most common neurological manifestations: cognitive impairment 78.5%, dysarthria 75.9%, ataxia 75.9%, vertical supranuclear gaze palsy 70.9%, dysphagia 69.6%; miglustat use 62.4% (85 patients), mean duration just over 4 years; antiepileptics 32.9%, antidepressants 11.8%, antacids 9.4% (pqac-00000010) | 10.1186/s13023-022-02200-4; https://doi.org/10.1186/s13023-022-02200-4 | (pqac-00000010) |
| US real-world claims analysis, acid sphingomyelinase deficiency type B (historical Niemann-Pick type B) | Mar 2023 | Primary cohort N=47; sensitivity cohort N=59 | 70% of the primary cohort were aged <18 years; liver, spleen, and lungs were the most frequently affected organs; 28 hospitalization events in the primary cohort and 40 in the sensitivity cohort; mean length of stay 6.71 days (95% CI 2.13–9.18) in primary cohort and 4.03 days (95% CI 2.22–4.77) in sensitivity cohort; longest stays: cardiovascular 11.0 days, other liver conditions 8.3 days, cirrhosis 7.5 days; respiratory disorders mean LoS 5.71 days; medication rates in primary cohort: antibiotics 809.6 prescriptions/1000 PY (55.3% of patients), HMG-CoA inhibitors 738.0/1000 PY (12.8%), respiratory medications 666.4/1000 PY (29.8%); supplemental oxygen in 10.6%; splenectomy in 2.1%; outpatient visits driven mainly by cognitive/developmental/emotional problems and respiratory/lung disorders; respiratory/lung disorders accounted for most ED visits and hospitalizations (pqac-00000009, pqac-00000011) | 10.1007/s12325-023-02453-w; https://doi.org/10.1007/s12325-023-02453-w | (pqac-00000009, pqac-00000011) |
| Polish pediatric cohort update, chronic ASMD (visceral and neurovisceral forms) | Oct 2024 | N=7 | Phenotype split: chronic visceral 5/7 (71%), chronic neurovisceral 2/7 (29%); splenomegaly 7/7 (100%); mild liver enlargement 4/7 (57%); interstitial lung disease on imaging 7/7 (100%); cherry-red spot 5/7 (71%); hypercholesterolemia / elevated total cholesterol, LDL-C and triglycerides 6/7 (86%); decreased HDL-C 7/7 (100%); decreased 25-hydroxy-vitamin D 7/7 (100%); thrombocytopenia present at diagnosis in 1/7 (14%), later in 3/7 total (43%); lyso-sphingomyelin in dried blood spot elevated in all screened patients, with higher values in chronic neurovisceral cases; 7 distinct SMPD1 variants identified; missense variants comprised 71% of alleles (pqac-00000012, pqac-00000013, pqac-00000014, pqac-00000015) | 10.17219/acem/193696; https://doi.org/10.17219/acem/193696 | (pqac-00000012, pqac-00000013, pqac-00000014, pqac-00000015) |
| Why these data matter for “type E” | 2022–2024 contextual synthesis | — | Modern datasets are organized around molecularly defined entities—NPC and ASMD—not “type E.” These quantitative studies show that current research and care pathways classify patients by NPC1/NPC2-related NPC or SMPD1-related ASMD, reinforcing that historical “type E” is obsolete and should be replaced by enzyme/biomarker/genetic diagnosis (pqac-00000003, pqac-00000006, pqac-00000021, pqac-00000023) | ASMD guideline: 10.1186/s13023-023-02686-6; https://doi.org/10.1186/s13023-023-02686-6 | (pqac-00000003, pqac-00000006, pqac-00000021, pqac-00000023) |


*Table: This table compiles key 2022-2024 quantitative findings from NPC and ASMD studies that contextualize the obsolete Niemann-Pick disease type E label. It highlights how modern evidence is organized around molecularly defined disorders rather than historical subtype E.*