Acid Sphingomyelinase Deficiency

The study of splenomegaly, and the follow-up of splenectomized patients, is one of the causes of referral of these patients to pediatric gastroenterology and oncohematology clinics, and adult internal medicine and hematology. The study and management of splenomegaly is well described among the different medical specialties to which these patients arrive. After the application of the different algorithms and the different studies that are carried out, these splenomegaly are identified as being of hepatic, infectious, inflammatory, congestive, hematological origin and primary causes. Despite these studies of splenomegaly, approximately 10-15% of these patients still remain undiagnosed. Several studies have suggested that there is an increased frequency of MGUS (monoclonal gammopathy of undetermined significance) and/or multiple myeloma (MM) among Gaucher patients. Regarding ASMD (Acid Sphingomyelinase Deficiency), few studies have been published but it seems the 21% of patient with ASMD has MGUS and 15% ASMD patients have MGUS. Moreover, patients with MGUS and Gaucher disease (GD) are at increased risk of developing MM. The objective of the present study is to increase the diagnostic sensitivity of these unknown splenomegalys, or unknown splenomegaly patients with MGUS or multiple myeoloma who remain in consultations, using the usual diagnostic clinical procedures of unknown splenomegaly and unknown splenectomy patients, where we include the extraction of a blood sample for dry drop test (DBS), where the determination of the enzymatic/genetic activity will be carried out for Gaucher disease (GD) and acid sphingomyelinase deficiency (ASMD) , analysis of LisoGl1 and LisoSM.

US, multicenter, cohort, open label observational study with primary data collection. Ancillary protocol-specified procedures to address the study objectives (eg, assessment of ADA) may be considered outside the standard of care for acid sphingomyelinase deficiency (ASMD), but the study methodology remains non-interventional, as the additional collection of data from participants will not dictate treatment. The total overall study duration will be 5 years. The follow-up period will be a minimum of 1 year to a maximum of 3 years. The enrollment period will be up to 4 years, to allow a minimum of 1 year of follow-up for the last participant enrolled.