Lysosomal Storage Disorders: Haematology Perspective

Abstract

Lysosomal storage disorders (LSDs) are a collection of rare genetic diseases each causing a specific lysosomal enzyme deficiency which results in increased substrate “storage” with pathological consequences. Gaucher disease (GD) is one of the most common LSDs, though time to diagnosis from initial presentation can be considerable with some studies demonstrating a median time from symptom onset to diagnosis of 2 years (range 0.5–26 years) (Thomas et al. 2013). It has been shown that due to clinical features of hepatosplenomegaly, cytopenias and bleeding diatheses, approximately 75 % of patients will see a haematologist prior to their diagnosis being established, and patients will see a mean of three specialists before a diagnosis is made (Mistry et al. 2007). Although there has been increased awareness of the disease since the availability of treatment, there has been no significant decrease in the time taken to make the diagnosis (Thomas et al. 2013). There are over 60 LSDs, all of which are rare, and as a result may go undiagnosed or misdiagnosed for some time. Many of them have features that could present either clinically to a haematologist or have features on a blood film or bone marrow that may include them as a differential. Some LSDs have associations with haematological malignancy while others have been successfully treated with haematopoietic stem cell transplantation. Therefore, it is important that haematologists have an awareness of the various LSDs despite their rarity since they may be able to play a vital role in their diagnosis and management. This is increasingly relevant as new treatments are developed and improved.