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The official name of this gene is “palmitoyl-protein thioesterase 1.”
PPT1 is the gene's official symbol. The PPT1 gene is also known by other names, listed below.
The PPT1 gene provides instructions for making a protein called palmitoyl-protein thioesterase 1. This protein is found in structures called lysosomes, which are compartments within cells that break down and recycle different types of molecules. Palmitoyl-protein thioesterase 1 removes certain fats called long-chain fatty acids from other proteins so the fats can be broken down and used for energy.
Palmitoyl-protein thioesterase 1 is thought to be involved in a variety of cell functions. These functions include transporting materials from the cell surface into the cell (endocytosis), the movement of small sac-like structures called vesicles that transport certain substances within cells (vesicle trafficking), and the self-destruction of cells (apoptosis). Palmitoyl-protein thioesterase 1 is also thought to play a role in the functioning of synapses, which are the connections between nerve cells (neurons) where cell-to-cell communication occurs.
At least three mutations in the PPT1 gene have been found to cause Kufs disease. These mutations change single protein building blocks (amino acids) or create a premature stop signal in the instructions used to make palmitoyl-protein thioesterase 1. The PPT1 gene mutations that cause Kufs disease are thought to allow some functional protein to be produced. The small amount of functional protein likely accounts for the development of signs and symptoms later in life, usually around age 30. However, it is unclear how PPT1 gene mutations cause the movement problems and cognitive decline characteristic of Kufs disease.
Mutations in the PPT1 gene are responsible for some neuronal ceroid lipofuscinoses (NCLs), a group of diseases that includes Kufs disease. The features of NCLs include a loss of intellectual functions (dementia), seizures, movement disorders, and progressive vision loss. A fatty substance called a lipopigment builds up in the cells of many affected individuals. The buildup of this substance is thought to damage cells and may ultimately cause cell death, contributing to the signs and symptoms of NCLs.
In addition to Kufs disease, mutations in the PPT1 gene cause the infantile, late-infantile, and juvenile types of NCL. These conditions are differentiated by the age at which signs and symptoms first appear: the infantile form of NCL appears between ages six months and two years, the late infantile form appears between ages two and four, and the juvenile form appears between ages five and nine. Researchers believe that PPT1 gene mutations that allow more functional palmitoyl-protein thioesterase 1 to be produced result in later appearance of the features of NCL. For example, PPT1 gene mutations that cause infantile NCL result in a nearly complete loss of palmitoyl-protein thioesterase 1 activity, while mutations responsible for the juvenile form of the disorder result in a protein that is partially active.
PPT1 gene mutations account for all known cases of infantile NCL; more than 25 mutations have been identified. Mutations in the PPT1 gene are responsible for a small proportion of cases of late infantile NCL and juvenile NCL.
Cytogenetic Location: 1p32
Molecular Location on chromosome 1: base pairs 40,538,381 to 40,563,141
The PPT1 gene is located on the short (p) arm of chromosome 1 at position 32.
More precisely, the PPT1 gene is located from base pair 40,538,381 to base pair 40,563,141 on chromosome 1.
See How do geneticists indicate the location of a gene? (http://ghr.nlm.nih.gov/handbook/howgeneswork/genelocation) in the Handbook.
You and your healthcare professional may find the following resources about PPT1 helpful.
You may also be interested in these resources, which are designed for genetics professionals and researchers.
See How are genetic conditions and genes named? (http://ghr.nlm.nih.gov/handbook/mutationsanddisorders/naming) in the Handbook.
acids ; apoptosis ; cell ; ceroid ; dementia ; endocytosis ; fatty acids ; gene ; hydrolase ; juvenile ; protein ; vesicle
You may find definitions for these and many other terms in the Genetics Home Reference Glossary (http://www.ghr.nlm.nih.gov/glossary).
The resources on this site should not be used as a substitute for professional medical care or advice. Users seeking information about a personal genetic disease, syndrome, or condition should consult with a qualified healthcare professional. See How can I find a genetics professional in my area? (http://ghr.nlm.nih.gov/handbook/consult/findingprofessional) in the Handbook.