Lysosomal Storage Disease

Excerpt

Lysosomal storage diseases (LSDs) are diseases caused by defects in single-genes. Enzyme defects cause nearly seventy percent of the LSDs, and the rest are defects in enzyme activator or associated proteins. A gene on a particular chromosome locus transcribes a particular enzyme—improper enzyme-coding results in inactive enzymes. Similarly, defective activators result from mutations in activator genes. Seventy LSDs are described so far, and many more will likely be discovered in the future. Individually, they are rare, but they are common and justify the effort and expenditure invested in researching these conditions as a group.

These conditions cause disease of the organs in which they accumulate and decide the clinical signs and symptoms. Infants and children suffer more severely compared to adults. The clinical features are unique in many children and adults for the same disease. For example, the child's developing brain is more susceptible to insults and manifests symptoms and signs of dysfunction, while this may be milder or absent in adults.

The last decade has observed tremendous advances in understanding many of these conditions. These advances have shown promise in improving the lifespan and quality of life, which hitherto remained dismal. The pathology of LSDs resembles that of some degenerative conditions that present in later life and maybe the connecting link between these two.

Enzyme testing is usually the initial diagnostic test, but genetic analysis of the gene mutations adds precision. There are many modern therapeutic techniques for these conditions. When applied early before organ damage sets in, these therapies have the potential to prevent or delay damage, improve quality of life, and increase lifespan.This article summarizes the latest developments in the pathophysiology, investigations, and treatment of the more common LSDs and will improve healthcare outcomes.