Q. A 10-year-old boy is brought to the pediatric clinic by his parents. They express concerns about his growth, noting that he is significantly shorter than his peers. On examination, you notice significant hepatosplenomegaly. His medical history is notable for recurrent episodes of severe bone pain. X-rays have previously shown osteoporosis and avascular necrosis of the femur. Blood tests reveal pancytopenia. Further history taking reveals that the boy also experiences occasional breathing difficulties. A bone marrow aspirate displays mononuclear cells filled with lipids, resembling papers with creases. Based on the clinical presentation, what is the most likely diagnosis?