Galactosialidosis is a condition that affects many areas of the body. The three forms of galactosialidosis are distinguished by the age at which symptoms develop and the pattern of features.

Variants (also called mutations) in the CTSA gene cause all the forms of galactosialidosis. The CTSA gene provides instructions for making a protein called cathepsin A, which is active in cellular compartments called lysosomes. These compartments contain enzymes that digest and recycle materials when they are no longer needed. Cathepsin A works together with two enzymes, neuraminidase 1 and beta-galactosidase, to form a protein complex. This complex breaks down sugar molecules (oligosaccharides) attached to certain proteins (glycoproteins) or fats (glycolipids). Cathepsin A is also found on the cell surface, where it forms a complex with neuraminidase 1 and a protein called elastin-binding protein. Elastin-binding protein plays a role in the formation of elastic fibers, which are components of the connective tissues that make up the body's supportive framework.

The prevalence of galactosialidosis is unknown; more than 100 cases have been reported. The juvenile/adult form accounts for more than half of the reported cases of galactosialidosis.  Most people with this type of the condition are of Japanese descent.

This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell must have a variant to cause the disorder. The parents of an individual with an autosomal recessive condition each carry one copy of the altered gene, but they typically do not show signs and symptoms of the condition.

Published Date: January 26, 2024
Published By: National Institutes of Health