ALG12

On this page:

What is the official name of the ALG12 gene?

The official name of this gene is “ALG12, alpha-1,6-mannosyltransferase.”

ALG12 is the gene's official symbol. The ALG12 gene is also known by other names, listed below.

Read more about gene names and symbols on the About page.

What is the normal function of the ALG12 gene?

The ALG12 gene provides instructions for making an enzyme that is involved in a process called glycosylation. During this process, complex chains of sugar molecules (oligosaccharides) are attached to proteins and fats (lipids). Glycosylation modifies proteins so they can fully perform their functions. Oligosaccharides are made up of many sugar molecules that are attached to one another in a stepwise process, forming a complex chain. The enzyme produced from the ALG12 gene transfers a simple sugar called mannose to growing oligosaccharides at a particular step in the formation of the chain. Once the correct number of sugar molecules are linked together, the oligosaccharide is attached to a protein or lipid.

Does the ALG12 gene share characteristics with other genes?

The ALG12 gene belongs to a family of genes called dolichyl D-mannosyl phosphate dependent mannosyltransferases (dolichyl D-mannosyl phosphate dependent mannosyltransferases).

A gene family is a group of genes that share important characteristics. Classifying individual genes into families helps researchers describe how genes are related to each other. For more information, see What are gene families? in the Handbook.

How are changes in the ALG12 gene related to health conditions?

ALG12-congenital disorder of glycosylation - caused by mutations in the ALG12 gene: At least 13 mutations in the ALG12 gene have been found to cause ALG12-congenital disorder of glycosylation (ALG12-CDG). This condition typically leads to delayed growth and development, weak muscle tone (hypotonia), and other signs and symptoms. Mutations in theALG12 gene result in the production of an abnormal enzyme with little activity. Without a properly functioning enzyme, mannose cannot be added to the chain efficiently, and the resulting oligosaccharides are often incomplete. Although the short oligosaccharides can be transferred to proteins and lipids, the process is not as efficient as with the full-length oligosaccharide. As a result, glycosylation is reduced. The wide variety of signs and symptoms in ALG12-CDG are likely due to impaired glycosylation of proteins and lipids that are needed for normal function in many organs and tissues, including the brain.

Where is the ALG12 gene located?

Cytogenetic Location: 22q13.33

Molecular Location on chromosome 22: base pairs 49,903,203 to 49,918,457

The ALG12 gene is located on the long (q) arm of chromosome 22 at position 13.33.

More precisely, the ALG12 gene is located from base pair 49,903,203 to base pair 49,918,457 on chromosome 22.

See How do geneticists indicate the location of a gene? in the Handbook.

Where can I find additional information about ALG12?

You and your healthcare professional may find the following resources about ALG12 helpful.

Educational resources - Information pages
Biochemistry (fifth edition, 2002): Carbohydrates Can Be Attached to Proteins to FormGlycoproteins
Gene Reviews - Clinical summary
Genetic Testing Registry - Repository of genetic test information (1 link)

You may also be interested in these resources, which are designed for genetics professionals and researchers.

PubMed - Recent literature
OMIM - Genetic disorder catalog
Research Resources - Tools for researchers (4 links)

What other names do people use for the ALG12 gene or gene products?

asparagine-linked glycosylation 12, alpha-1,6-mannosyltransferase homolog
asparagine-linked glycosylation 12 homolog (S. cerevisiae, alpha-1,6-mannosyltransferase)
asparagine-linked glycosylation 12 homolog (yeast, alpha-1,6-mannosyltransferase)
asparagine-linked glycosylation protein 12 homolog
CDG1G
dolichyl-P-Man:Man(7)GlcNAc(2)-PP-dolichol alpha-1,6-mannosyltransferase
dolichyl-P-Man:Man(7)GlcNAc(2)-PP-dolichyl-alpha-1,6-mannosyltransferase
dolichyl-P-mannose:Man-7-GlcNAc-2-PP-dolichyl-alpha-6-mannosyltransferase
dol-P-Man dependent alpha-1,6-mannosyltransferase
dol-P-Man:Man(7)GlcNAc(2)-PP-Dol alpha-1,6-mannosyltransferase
ECM39
hALG12
mannosyltransferase ALG12 homolog
membrane protein SB87
PP14673

See How are genetic conditions and genes named? in the Handbook.

Where can I find general information about genes?

The Handbook provides basic information about genetics in clear language.

These links provide additional genetics resources that may be useful.

What glossary definitions help with understanding ALG12?

asparagine ; congenital ; enzyme ; gene ; glycosylation ; hypotonia ; lipid ; mannose ; muscle tone ;oligosaccharides ; protein ; simple sugar

You may find definitions for these and many other terms in the Genetics Home Reference Glossary.

References (5 links)

The resources on this site should not be used as a substitute for professional medical care or advice. Users seeking information about a personal genetic disease, syndrome, or condition should consult with a qualified healthcare professional. See How can I find a genetics professional in my area? in the Handbook