Galactocerebrosidase

Galactocerebrosidase (also known as GALC) is an enzyme that is encoded by the GALC gene in humans. This enzyme is crucial for the metabolism of certain lipids in the body, specifically galactolipids, which are abundant in the nervous system.

Function

Galactocerebrosidase is a lysosomal enzyme that catalyzes the hydrolysis of galactose from galactocerebroside, a primary lipid in the myelin sheath. This process is essential for the normal functioning of the nervous system. Deficiency of this enzyme can lead to the accumulation of galactocerebroside and related lipids in the body, causing a group of genetic disorders known as leukodystrophies.

Structure

The GALC gene is located on the long (q) arm of chromosome 14 at position 31. The gene spans about 60 kilobases and contains 17 exons. The encoded enzyme is a large protein with a molecular weight of approximately 80 kilodaltons.

Clinical significance

Deficiency of galactocerebrosidase is associated with Krabbe disease, a rare and often fatal leukodystrophy. Symptoms of Krabbe disease include progressive neurological deterioration, muscle weakness, and developmental delay. The disease is inherited in an autosomal recessive manner, meaning both copies of the gene in each cell must have mutations for the disease to be expressed.

File:Krabbe disease - high mag.jpg

Histopathology of Krabbe disease, showing globoid cells and loss of myelin

See also

• Lysosomal storage disease
• Sphingolipid
• Globoid cell leukodystrophy