A 17-year-old female patient has gradually developed symptoms such as fatigue, weakness, dyspnea on exertion and impaired

performance over several months. These symptoms gradually worsen over the last

year or so. She now comes for intense right hip pain. On further questioning,

she indicates frequent epistaxis (nosebleeds) and easy development of bruises.

During the physical examination, the physician notes striking pallor of the

skin and mucous membranes, tachycardia as well as hepatomegaly (enlargement of the

liver) and splenomegaly (enlargement of the spleen). Laboratory findings

confirm the presence of anemia and thrombocytopenia. A special finding is the

picture of the so-called Erlenmeyer flask deformity of the diaphyses of the

femurs. This sign is already suggestive to the physicians and the determination

of low activity of the enzyme β-glucocerebrosidase in isolated leukocytes

confirms the diagnosis of Gaucher disease. Gaucher disease is an inherited

lysosomal storage disease that is caused by a genetic defect in the lysosomal

enzyme glucocerebrosidase. This enzyme is responsible for the hydrolytic

cleavage of glucosylceramide to glucose and ceramide. What is the function of

lysosomes? What will their failure lead to in the cell?