What does the SMPD1 gene do?
The SMPD1 gene provides instructions for making an enzyme called acid sphingomyelinase. This enzyme is found in lysosomes, which are small compartments in the cell that digest and recycle molecules.
What does sphingomyelinase do?
Acid sphingomyelinase is one of the enzymes that make up the sphingomyelinase (SMase) family, responsible for catalyzing the breakdown of sphingomyelin to ceramide and phosphorylcholine. They are organized into alkaline, neutral, and acidic SMase depending on the pH in which their enzymatic activity is optimal.
Where is acid sphingomyelinase produced?
lysosomes
Acid sphingomyelinase (ASMase, ASM, SMPD1) is an enzyme found in lysosomes and in the extracellular space where it catalyses the conversion of sphingomyelin, a major component of membranes, into ceramide and phosphocholine1,2.
What is Niemann-Pick Type B?
Niemann-Pick disease type B is an inherited condition involving lipid metabolism. People with this condition experience a build up of lipids in the spleen, liver, lungs, bone marrow, and brain.
How is Niemann-Pick disease inherited?
The Niemann-Pick gene mutations are passed from parents to children in a pattern called autosomal recessive inheritance. This means that both the mother and the father must pass on the defective form of the gene for the child to be affected. Niemann-Pick is a progressive disease, and there is no cure.
What causes ASMD?
ASMD is caused by mutations in the SMPD1 gene and is inherited in an autosomal recessive manner. There are three disorders known as Niemann-Pick disease, types A, B, and C. These disorders were initially grouped together because similar symptoms, but we now know that they are different diseases.
What is the substrate for sphingomyelinase?
As indicated by their name, the primary substrate of these enzymes in mammals is SM, which is hydrolysed to yield ceramide and choline-phosphate (ChoP) (Jenkins et al., 2011).
What is Niemann-Pick Type A?
Niemann-Pick disease type A appears during infancy and is characterized by an enlarged liver and spleen ( hepatosplenomegaly ), failure to gain weight and grow at the expected rate (failure to thrive), and progressive deterioration of the nervous system.
What disease is NP C?
Niemann-Pick Type C (NPC) disease is a genetic, neurodegenerative disorder which causes progressive deterioration of the nervous system. It usually affects children by interfering with their ability to metabolize cholesterol. Adult onset may also occur.
How long can you live with Niemann-Pick Disease?
Niemann-Pick Type A is the most severe form of the disease, with an average life expectancy of 18 months. Type B represents a milder form of disease, and some patients live into late to mid teens, with a few surviving into adulthood.