Lysosomal Storage Diseases
What are Lysosomal Storage Diseases (LSDs)
Lysosomes are the body’s cleaning system. In normal function, waste materials at a cellular level are processed in the lysosomes, “recycled” by enzymes and broken down into simpler components for the cells to utilize. Lysosomal Storage Diseases, simply put, result when certain enzymes are not present. The result is that certain proteins and other byproducts accumulate and become toxic to the body. Depending on the type of deficiency, different body systems are affected. Currently there are more than 50 identified Lysosomal Storage Diseases and individually they are considered extremely rare, but as a whole affect roughly 1 in 7700 children.
While each Lysosomal Storage Disease is slightly different, many share common hurdles to overcome. For example, crossing the blood/brain barrier has been a tremendous challenge in creating potential therapies. We strongly believe that, by focusing on the common obstacles, the answers for one lysosomal storage disease may be the key to others as well.
Acid Sphingomyelinase Deficiency (ASMD), also known as
Niemann-Pick Types A & B
Niemann-Pick Type A
Niemann-Pick Type A (NPA) falls under the larger class of diseases known as lysosomal storage diseases and is caused by genetic mutations on the SMPD1 gene of the 11th chromosome. It causes a malfunction or absence of an enzyme called Acid Sphingomyelinase (ASM), which is responsible for metabolizing a special lipid called Sphingomyelin. If ASM is not functioning properly or is absent, sphingomyelin cannot be metabolized properly and accumulates within the cells of major organs such as the liver, spleen, lungs, and brain, eventually causing organ failure and death by age two.
Niemann-Pick Type B
In contrast to NPA, patients with NPB generally have little or no neurological involvement and may survive into late childhood or adulthood. Type B individuals usually have enlarged livers and spleens, and respiratory problems are common. These symptoms may cause cardiovascular stress and can lead to heart disease later in life. The life expectancy of patients with NPB is highly variable depending on the severity of their symptoms.