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The official name of this gene is “cathepsin D.”
CTSD is the gene's official symbol. The CTSD gene is also known by other names, listed below.
The CTSD gene provides instructions for making an enzyme called cathepsin D. Cathepsin D is one of a family of cathepsin proteins that act as proteases, which modify proteins by cutting them apart. Cathepsin D is found in many types of cells and is active in lysosomes, which are compartments within cells that digest and recycle different types of molecules. By cutting proteins apart, cathepsin D can break proteins down, turn on (activate) proteins, and regulate self-destruction of the cell (apoptosis).
Cathepsin D is produced as an inactive enzyme, called a preproenzyme, which has extra protein segments attached. These segments must be removed, followed by additional processing steps, for the enzyme to become active.
The CTSD gene belongs to a family of genes called CTS (cathepsins).
A gene family is a group of genes that share important characteristics. Classifying individual genes into families helps researchers describe how genes are related to each other. For more information, see What are gene families? (http://ghr.nlm.nih.gov/handbook/howgeneswork/genefamilies) in the Handbook.
At least four mutations in the CTSD gene have been found to cause congenital neuronal ceroid lipofuscinosis (NCL). Congenital NCL is characterized by muscle rigidity, respiratory failure, severe seizures, and death in infancy. The CTSD gene mutations that cause congenital NCL lead to a complete lack of cathepsin D enzyme activity. As a result, proteins and other materials are not broken down properly. In the lysosomes, these substances accumulate into fatty substances called lipopigments. These accumulations occur in cells throughout the body, but neurons are likely particularly vulnerable to damage caused by the abnormal cell materials and the loss of cathepsin D function. Early and widespread cell death in congenital NCL leads to severe signs and symptoms and death in infancy.
Cytogenetic Location: 11p15.5
Molecular Location on chromosome 11: base pairs 1,752,751 to 1,763,991
The CTSD gene is located on the short (p) arm of chromosome 11 at position 15.5.
More precisely, the CTSD gene is located from base pair 1,752,751 to base pair 1,763,991 on chromosome 11.
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 CTSD 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.
apoptosis ; cell ; ceroid ; congenital ; enzyme ; gene ; protease ; protein ; respiratory
You may find definitions for these and many other terms in the Genetics Home Reference Glossary (http://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.