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MANBA gene

mannosidase beta

Normal Function

The MANBA gene provides instructions for making the enzyme beta-mannosidase. This enzyme works in the lysosomes, which are compartments that digest and recycle materials in the cell. Within lysosomes, the enzyme helps break down complexes of sugar molecules (oligosaccharides) attached to proteins called glycoproteins. Beta-mannosidase is involved in the last step of this process, helping to break down complexes of two-sugar molecules (disaccharides) containing a sugar molecule called mannose.

Health Conditions Related to Genetic Changes


Variants (also known as mutations) in the MANBA gene cause beta-mannosidosis. This disorder affects the way certain sugar molecules are processed in the body, resulting in various nervous system problems. The gene variants that cause beta-mannosidosis result in a beta-mannosidase enzyme with little or no activity. As a result the enzyme is unable to perform its role in breaking down mannose-containing disaccharides. These disaccharides gradually accumulate in the lysosomes and cause cells to malfunction, resulting in the signs and symptoms of beta-mannosidosis.

More About This Health Condition

Other Names for This Gene

  • MANB1
  • mannanase
  • mannase
  • mannosidase, beta A, lysosomal

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


  • Alkhayat AH, Kraemer SA, Leipprandt JR, Macek M, Kleijer WJ, Friderici KH. Human beta-mannosidase cDNA characterization and first identification of a mutation associated with human beta-mannosidosis. Hum Mol Genet. 1998 Jan;7(1):75-83. doi: 10.1093/hmg/7.1.75. Citation on PubMed
  • Bedilu R, Nummy KA, Cooper A, Wevers R, Smeitink J, Kleijer WJ, Friderici KH. Variable clinical presentation of lysosomal beta-mannosidosis in patients with null mutations. Mol Genet Metab. 2002 Dec;77(4):282-90. doi: 10.1016/s1096-7192(02)00172-5. Citation on PubMed
  • Essentials of Glycobiology (1999): Glycoprotein Degradation
  • Gort L, Duque J, Fabeiro JM, Zulaica A, Coll MJ, Chabas A. Molecular analysis in two beta-mannosidosis patients: description of a new adult case. Mol Genet Metab. 2006 Dec;89(4):398-400. doi: 10.1016/j.ymgme.2006.07.001. Epub 2006 Aug 14. Citation on PubMed
  • Molho-Pessach V, Bargal R, Abramowitz Y, Doviner V, Ingber A, Raas-Rothschild A, Ne'eman Z, Zeigler M, Zlotogorski A. Angiokeratoma corporis diffusum in human beta-mannosidosis: Report of a new case and a novel mutation. J Am Acad Dermatol. 2007 Sep;57(3):407-12. doi: 10.1016/j.jaad.2007.01.037. Epub 2007 Apr 8. Citation on PubMed
  • Uchino Y, Fukushige T, Yotsumoto S, Hashiguchi T, Taguchi H, Suzuki N, Konohana I, Kanzaki T. Morphological and biochemical studies of human beta-mannosidosis: identification of a novel beta-mannosidase gene mutation. Br J Dermatol. 2003 Jul;149(1):23-9. doi: 10.1046/j.1365-2133.2003.05365.x. Citation on PubMed
  • Zhu M, Lovell KL, Patterson JS, Saunders TL, Hughes ED, Friderici KH. Beta-mannosidosis mice: a model for the human lysosomal storage disease. Hum Mol Genet. 2006 Feb 1;15(3):493-500. doi: 10.1093/hmg/ddi465. Epub 2005 Dec 23. 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.