Table 2 Classification of patients with ASMD
Infantile neurovisceral (ASMD type A) | Chronic neurovisceral (intermediate ASMD, ASMD A/B, variant ASMD B) | Chronic visceral (ASMD type B) | |
|---|---|---|---|
Phenotype | Infantile onset of severe visceral involvement and neurodegeneration with progressive psychomotor deterioration | Visceral features of NPD B as well as neurologic findings including ataxia, variable degrees of developmental delay and peripheral neuropathy | Chronic progressive multi-system or oligosymptomatic, stable disease with no or little neurologic involvement |
Natural History | Relentless progression of neurologic and visceral disease and death typically by 3 years of age | Wide spectrum of disease manifestations and severity, with slow progression Patients live past early childhood and sometimes into adulthood | Wide spectrum of disease manifestations and severity. Sometimes oligosymptomatic. Survival usually extends well into adulthood and may even be normal. Patient may remain stable for years |