Niemann-pick types a/b
Causes
What gene change/mutation causes Niemann-Pick disease (SMPD1-associated)?
Niemann-Pick disease (SMPD1-associated) is caused by changes/mutations in the SMPD1 gene (sphingomyelin phosphodiesterase 1). Both types A and B are caused by changes/mutations in this gene. SMPD1 gives instructions to produce an enzyme called "acid sphingomyelinase", which is found in the lysosomes of the cell. Lysosomes are the part of the cell that help break down and recycle molecules and waste. Acid sphingomyelinase helps to break down a specific fat (called sphingomyelin) into another type of fat (called ceramide). Since sphingomyelin fat cannot be broken down in the cell, the fat builds up and the cell is unable to function properly and eventually dies.
More Causes Content
What happens because of the associated gene change/mutation in Niemann-Pick disease (SMPD1-associated)?
When there are changes/mutations in the SMPD1 gene, the cell cannot make enough of an enzyme called "acid sphingomyelinase". Without enough of this enzyme, a fat called "sphingomyelin" cannot be broken down into another fat called "ceramide". In Niemann-Pick disease (SMPD1-associated) this leads to a build-up of sphingomyelin in the cell, which damages the cell and causes it to malfunction and eventually die. As this continues, too many cells die and organs are damaged, especially the brain, lungs, liver, and spleen.
Is a genetic change/mutation in SMPD1 a predisposition or a cause of Niemann-Pick disease (SMPD1-associated)?
Changes/mutations in SMPD1 cause Niemann-Pick disease (SMPD1-associated). All individuals have two copies of the SMPD1 gene. People with changes/mutations in both copies of the SMPD1 gene will have symptoms of the condition.
