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Genetics Home Reference: your guide to understanding genetic conditions
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MKKS

Reviewed May 2010

What is the official name of the MKKS gene?

The official name of this gene is “McKusick-Kaufman syndrome.”

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

What is the normal function of the MKKS gene?

The MKKS gene provides instructions for making a protein that plays an important role in the formation of the limbs, heart, and reproductive system. The structure of this protein suggests that it may act as a chaperonin, which is a protein that helps fold other proteins. Proteins must be folded into the correct 3-dimensional shape to perform their usual functions in the body. Abnormally folded proteins can also interfere with the functions of normal proteins.

Although the structure of the MKKS protein is similar to that of a chaperonin, some studies have suggested that protein folding may not be this protein's primary function. Within cells, the MKKS protein is associated with structures called centrosomes. Centrosomes play a role in cell division and the assembly of microtubules, which are proteins that transport materials in cells and help the cell maintain its shape. Researchers speculate that the MKKS protein may be involved in transporting other proteins within the cell.

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

McKusick-Kaufman syndrome - caused by mutations in the MKKS gene

Two mutations in the MKKS gene have been identified in people with McKusick-Kaufman syndrome in the Old Order Amish population. Each of these mutations changes a single protein building block (amino acid) in the MKKS protein. One mutation replaces the amino acid histidine with the amino acid tyrosine at protein position 84 (written as His84Tyr or H84Y). The other mutation replaces the amino acid alanine with the amino acid serine at protein position 242 (written as Ala242Ser or A242S). Affected Amish people have these two mutations in both copies of the MKKS gene.

The mutations that underlie McKusick-Kaufman syndrome alter the structure of the MKKS protein. Although the altered protein disrupts the development of several parts of the body before birth, it is unclear how MKKS mutations lead to the specific features of this disorder.

The signs and symptoms of McKusick-Kaufman syndrome overlap significantly with those of another condition called Bardet-Biedl syndrome, which can make the two conditions difficult to tell apart in infancy and early childhood. Although both syndromes can be caused by changes in the MKKS gene, it remains unclear why some mutations cause McKusick-Kaufman syndrome and others cause Bardet-Biedl syndrome.

Where is the MKKS gene located?

Cytogenetic Location: 20p12

Molecular Location on chromosome 20: base pairs 10,404,779 to 10,434,238

The MKKS gene is located on the short (p) arm of chromosome 20 at position 12.

The MKKS gene is located on the short (p) arm of chromosome 20 at position 12.

More precisely, the MKKS gene is located from base pair 10,404,779 to base pair 10,434,238 on chromosome 20.

See How do geneticists indicate the location of a gene? (http://ghr.nlm.nih.gov/handbook/howgeneswork/genelocation) in the Handbook.

Where can I find additional information about MKKS?

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

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

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

  • Bardet-Biedl syndrome 6 protein
  • BBS6
  • HMCS
  • KMS
  • MKKS_HUMAN
  • MKS

See How are genetic conditions and genes named? (http://ghr.nlm.nih.gov/handbook/mutationsanddisorders/naming) in the Handbook.

What glossary definitions help with understanding MKKS?

alanine ; amino acid ; cell ; cell division ; chaperone ; gene ; histidine ; mutation ; population ; protein ; serine ; syndrome ; tyrosine

You may find definitions for these and many other terms in the Genetics Home Reference Glossary (http://www.ghr.nlm.nih.gov/glossary).

References

  • Hirayama S, Yamazaki Y, Kitamura A, Oda Y, Morito D, Okawa K, Kimura H, Cyr DM, Kubota H, Nagata K. MKKS is a centrosome-shuttling protein degraded by disease-causing mutations via CHIP-mediated ubiquitination. Mol Biol Cell. 2008 Mar;19(3):899-911. Epub 2007 Dec 19. (http://www.ncbi.nlm.nih.gov/pubmed/18094050?dopt=Abstract)
  • Katsanis N, Beales PL, Woods MO, Lewis RA, Green JS, Parfrey PS, Ansley SJ, Davidson WS, Lupski JR. Mutations in MKKS cause obesity, retinal dystrophy and renal malformations associated with Bardet-Biedl syndrome. Nat Genet. 2000 Sep;26(1):67-70. (http://www.ncbi.nlm.nih.gov/pubmed/10973251?dopt=Abstract)
  • Kim JC, Ou YY, Badano JL, Esmail MA, Leitch CC, Fiedrich E, Beales PL, Archibald JM, Katsanis N, Rattner JB, Leroux MR. MKKS/BBS6, a divergent chaperonin-like protein linked to the obesity disorder Bardet-Biedl syndrome, is a novel centrosomal component required for cytokinesis. J Cell Sci. 2005 Mar 1;118(Pt 5):1007-20. (http://www.ncbi.nlm.nih.gov/pubmed/15731008?dopt=Abstract)
  • NCBI Gene (http://www.ncbi.nlm.nih.gov/gene/8195)
  • Slavotinek AM, Biesecker LG. Unfolding the role of chaperones and chaperonins in human disease. Trends Genet. 2001 Sep;17(9):528-35. Review. (http://www.ncbi.nlm.nih.gov/pubmed/11525836?dopt=Abstract)
  • Slavotinek AM, Searby C, Al-Gazali L, Hennekam RC, Schrander-Stumpel C, Orcana-Losa M, Pardo-Reoyo S, Cantani A, Kumar D, Capellini Q, Neri G, Zackai E, Biesecker LG. Mutation analysis of the MKKS gene in McKusick-Kaufman syndrome and selected Bardet-Biedl syndrome patients. Hum Genet. 2002 Jun;110(6):561-7. Epub 2002 May 9. (http://www.ncbi.nlm.nih.gov/pubmed/12107442?dopt=Abstract)
  • Slavotinek AM, Stone EM, Mykytyn K, Heckenlively JR, Green JS, Heon E, Musarella MA, Parfrey PS, Sheffield VC, Biesecker LG. Mutations in MKKS cause Bardet-Biedl syndrome. Nat Genet. 2000 Sep;26(1):15-6. Erratum in: Nat Genet 2001 Jun;28(2):193. (http://www.ncbi.nlm.nih.gov/pubmed/10973238?dopt=Abstract)
  • Stone DL, Slavotinek A, Bouffard GG, Banerjee-Basu S, Baxevanis AD, Barr M, Biesecker LG. Mutation of a gene encoding a putative chaperonin causes McKusick-Kaufman syndrome. Nat Genet. 2000 May;25(1):79-82. (http://www.ncbi.nlm.nih.gov/pubmed/10802661?dopt=Abstract)

 

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? (http://ghr.nlm.nih.gov/handbook/consult/findingprofessional) in the Handbook.

 
Reviewed: May 2010
Published: July 21, 2014