A Prospective and Retrospective Cohort Study in Patients With Chronic Forms of Acid Sphingomyelinase Deficiency (ASMD)

Primary Objective: * To describe the clinical features and their severity at the time of diagnosis and their evolution over time in patients with confirmed chronic visceral and chronic neurovisceral forms of ASMD * To describe Clinician-Reported Outcomes (ClinROs) and Patient-Reported Outcomes (PROs) at enrollment and their evolution over time; disease severity at the time of diagnosis and its evolution over time Secondary Objectives: * To describe abnormal values in laboratory parameters and all values of specific clinical and imaging assessments at the time of diagnosis and their evolution over time * To study the use and applicability towards validation of a newly developed ASMD disease severity scoring system * To study the use and applicability towards validation of a newly developed ASMD PRO tool * To describe ASMD-related disease burden among patients with ASMD, caregivers, and healthcare resource utilization * To describe the association between patient demographics (eg, age, gender, race, Ashkenazi ancestry) and genotype with selected clinical features in patients with confirmed chronic visceral and chronic neurovisceral forms of ASMD