CHIT1 Gene: Chitinase 1 - Function, Mutations, and Disease Associations

The CHIT1 gene encodes chitinase 1, also known as chitotriosidase, an enzyme that hydrolyzes chitin, a structural polysaccharide found in fungal cell walls, arthropod exoskeletons, and nematodes. It is primarily expressed in activated macrophages and plays a role in innate immune defense against chitin-containing pathogens. Mutations in CHIT1 are associated with Gaucher disease and other lysosomal storage disorders, where enzyme activity is elevated as a biomarker.

Tissue Expression

Cell Line Expression

Hotspot Mutations

Mutation functional classification

• Chitin degradation (Reactome: R-HSA-2024096)

• Innate immune system (Reactome: R-HSA-168249)

Chitinase 1 (chitotriosidase) is a 50 kDa secreted enzyme composed of an N-terminal catalytic domain and a C-terminal chitin-binding domain. It is produced primarily by activated macrophages and neutrophils. The enzyme cleaves chitin polymers into smaller fragments, contributing to host defense against fungi, parasites, and insects. In Gaucher disease, elevated plasma chitotriosidase activity serves as a biomarker for macrophage activation and treatment response. A common 24-bp duplication in exon 10 leads to a null allele with no enzyme activity, found in approximately 6% of the population.