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FUCA1 gene

alpha-L-fucosidase 1

Normal Function

The FUCA1 gene provides instructions for making an enzyme called alpha-L-fucosidase. This enzyme is found in lysosomes, which are compartments in the cell that digest and recycle materials. Within lysosomes, this enzyme plays a role in the breakdown of complexes of sugar molecules (oligosaccharides) attached to certain proteins (glycoproteins) and fats (glycolipids). Alpha-L-fucosidase is responsible for cutting (cleaving) off a sugar molecule called fucose toward the end of the breakdown process.

Health Conditions Related to Genetic Changes


At least 26 mutations in the FUCA1 gene have been found to cause fucosidosis. Most of these mutations result in an abnormally short, nonfunctional alpha-L-fucosidase enzyme. Without this enzyme, glycolipids and glycoproteins cannot be completely broken down. These partially broken down compounds accumulate in the lysosomes and cause cells throughout the body to malfunction. Brain cells are particularly sensitive to the buildup of glycolipids and glycoproteins, which can result in cell death. Loss of brain cells is thought to cause the neurological symptoms of fucosidosis. Accumulation of glycolipids and glycoproteins also occurs in other organs such as the liver, spleen, skin, heart, pancreas, and kidneys, contributing to the additional symptoms of fucosidosis.

More About This Health Condition

Other Names for This Gene

  • alpha-L-fucosidase
  • fucosidase, alpha-L- 1, tissue

Additional Information & Resources

Tests Listed in the Genetic Testing Registry

Scientific Articles on PubMed

Catalog of Genes and Diseases from OMIM

Gene and Variant Databases


  • Cragg H, Williamson M, Young E, O'Brien J, Alhadeff J, Fang-Kircher S, Paschke E, Winchester B. Fucosidosis: genetic and biochemical analysis of eight cases. J Med Genet. 1997 Feb;34(2):105-10. doi: 10.1136/jmg.34.2.105. Citation on PubMed or Free article on PubMed Central
  • Willems PJ, Gatti R, Darby JK, Romeo G, Durand P, Dumon JE, O'Brien JS. Fucosidosis revisited: a review of 77 patients. Am J Med Genet. 1991 Jan;38(1):111-31. doi: 10.1002/ajmg.1320380125. Citation on PubMed
  • Willems PJ, Seo HC, Coucke P, Tonlorenzi R, O'Brien JS. Spectrum of mutations in fucosidosis. Eur J Hum Genet. 1999 Jan;7(1):60-7. doi: 10.1038/sj.ejhg.5200272. Citation on PubMed

The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health.