Primary Objective:

To assess prevalence of Gaucher disease (GD) diagnosed in pediatric patients presenting with unexplained splenomegaly (SMG) after exclusion of first intention-diagnoses (e.g. portal hypertension, haematological malignancy, hemolytic anemia, infection) based on clinical examination and routine biological tests (full blood count, reticulocytes, liver tests, abdominal ultrasound, Coombs test and Epstein Barr virus serology).

Secondary Objectives:

• To describe the rate of each identified disease category and the rate of patients with no final diagnosis at the end of the study in pediatric patients with unexplained SMG after exclusion of first intention diagnoses
• To describe the characteristics (clinical, lab, genetics) of all pediatric patients included in the study and to describe the characteristics subdivided by identified disease category and absence of final diagnosis at the end of the study

The planned duration of this study is 39 months, which includes 36 months of patient recruitment.

Inclusion criteria:

• Patient under the age of 18 years
• Patient with unexplained SMG (SMG defined as a palpable spleen, already known or discovered for the first time) and who has undergone tests to eliminate obvious causes of SMG

Exclusion criteria:

Patient with any obvious cause of SMG as described by clinical examination and/or lab or imaging test available in medical records and/or having been diagnosed with any of the following conditions:

1. hemolytic anemia
2. hematological malignancy
3. portal hypertension
4. infectious disease associated with SMG (Cytomegalovirus, Epstein Barr virus, leishmaniasis or other obvious infectious cause revealed by the medical history)

The above information is not intended to contain all considerations relevant to a patient's potential participation in a clinical trial.

Patient under 18 year-old with unexplained SMG (SMG defined as a palpable spleen, already known or discovered for the first time) and who has undergone tests to eliminate obvious causes of SMG including: hemolytic anemia, hematological malignancy, portal hypertension, infectious disease associated with SMG

Qualified researchers may request access to patient level data and related study documents including the clinical study report, study protocol with any amendments, blank case report form, statistical analysis plan, and dataset specifications. Patient level data will be anonymized and study documents will be redacted to protect the privacy of trial participants. Further details on Sanofi's data sharing criteria, eligible studies, and process for requesting access can be found at: https://vivli.org