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Genetics Home Reference: your guide to understanding genetic conditions
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Microcephalic osteodysplastic primordial dwarfism type II

(often shortened to MOPDII)
Reviewed January 2011

What is MOPDII?

Microcephalic osteodysplastic primordial dwarfism type II (MOPDII) is a condition characterized by short stature (dwarfism) with other skeletal abnormalities (osteodysplasia) and an unusually small head size (microcephaly). The growth problems in MOPDII are primordial, meaning they begin before birth, with affected individuals showing slow prenatal growth (intrauterine growth retardation). After birth, affected individuals continue to grow at a very slow rate. The final adult height of people with this condition ranges from 20 inches to 40 inches. Other skeletal abnormalities in MOPDII include abnormal development of the hip joints (hip dysplasia), thinning of the bones in the arms and legs, an abnormal side-to-side curvature of the spine (scoliosis), and shortened wrist bones. In people with MOPDII head growth slows over time; affected individuals have an adult brain size comparable to that of a 3-month-old infant. However, intellectual development is typically normal.

People with this condition typically have a high-pitched, nasal voice that results from a narrowing of the voicebox (subglottic stenosis). Facial features characteristic of MOPDII include a prominent nose, full cheeks, a long midface, and a small jaw. Other signs and symptoms seen in some people with MOPDII include small teeth (microdontia) and farsightedness. Over time, affected individuals may develop areas of abnormally light or dark skin coloring (pigmentation).

Many individuals with MOPDII have blood vessel abnormalities. For example, some affected individuals develop a bulge in one of the blood vessels at the center of the brain (intracranial aneurysm). These aneurysms are dangerous because they can burst, causing bleeding within the brain. Some affected individuals have Moyamoya disease, in which arteries at the base of the brain are narrowed, leading to restricted blood flow. These vascular abnormalities are often treatable, though they increase the risk of stroke and reduce the life expectancy of affected individuals.

How common is MOPDII?

MOPDII appears to be a rare condition, although its prevalence is unknown.

What genes are related to MOPDII?

Mutations in the PCNT gene cause MOPDII. The PCNT gene provides instructions for making a protein called pericentrin. Within cells, this protein is located in structures called centrosomes. Centrosomes, which are part of chromosomes, play a role in cell division and the assembly of microtubules. Microtubules are fibers that help cells maintain their shape, assist in the process of cell division, and are essential for the transport of materials within cells. Pericentrin acts as an anchoring protein, securing other proteins to the centrosome. Through its interactions with these proteins, pericentrin plays a role in regulation of the cell cycle, which is the cell's way of replicating itself in an organized, step-by-step fashion.

PCNT gene mutations lead to the production of a nonfunctional pericentrin protein that cannot anchor other proteins to the centrosome. As a result, centrosomes cannot properly assemble microtubules, leading to disruption of the cell cycle and cell division. Impaired cell division causes a reduction in cell production, while disruption of the cell cycle can lead to cell death. This overall reduction in the number of cells leads to short bones, microcephaly, and the other signs and symptoms of MOPDII.

Related Gene(s)

Changes in this gene are associated with microcephalic osteodysplastic primordial dwarfism type II.

  • PCNT

How do people inherit MOPDII?

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

Where can I find information about diagnosis or management of MOPDII?

These resources address the diagnosis or management of MOPDII and may include treatment providers.

  • Genetic Testing Registry: Microcephalic osteodysplastic primordial dwarfism type 2 (http://www.ncbi.nlm.nih.gov/gtr/conditions/C1859451)

You might also find information on the diagnosis or management of MOPDII in Educational resources (http://www.ghr.nlm.nih.gov/condition/microcephalic-osteodysplastic-primordial-dwarfism-type-ii/show/Educational+resources) and Patient support (http://www.ghr.nlm.nih.gov/condition/microcephalic-osteodysplastic-primordial-dwarfism-type-ii/show/Patient+support).

General information about the diagnosis (http://ghr.nlm.nih.gov/handbook/consult/diagnosis) and management (http://ghr.nlm.nih.gov/handbook/consult/treatment) of genetic conditions is available in the Handbook. Read more about genetic testing (http://ghr.nlm.nih.gov/handbook/testing), particularly the difference between clinical tests and research tests (http://ghr.nlm.nih.gov/handbook/testing/researchtesting).

To locate a healthcare provider, see How can I find a genetics professional in my area? (http://ghr.nlm.nih.gov/handbook/consult/findingprofessional) in the Handbook.

Where can I find additional information about MOPDII?

You may find the following resources about MOPDII helpful. These materials are written for the general public.

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

What other names do people use for MOPDII?

  • Majewski osteodysplastic primordial dwarfism type II
  • MOPD2
  • osteodysplastic primordial dwarfism type II

For more information about naming genetic conditions, see the Genetics Home Reference Condition Naming Guidelines (http://ghr.nlm.nih.gov/ConditionNameGuide) and How are genetic conditions and genes named? (http://ghr.nlm.nih.gov/handbook/mutationsanddisorders/naming) in the Handbook.

What if I still have specific questions about MOPDII?

Ask the Genetic and Rare Diseases Information Center (http://rarediseases.info.nih.gov/GARD/).

What glossary definitions help with understanding MOPDII?

aneurysm ; arteries ; autosomal ; autosomal recessive ; cell ; cell cycle ; cell division ; centrosome ; dwarfism ; dysplasia ; gene ; inherited ; intrauterine growth retardation ; microcephalic ; microcephaly ; pigmentation ; prenatal ; prevalence ; protein ; recessive ; scoliosis ; short stature ; stature ; stenosis ; vascular

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

References

  • Bober MB, Khan N, Kaplan J, Lewis K, Feinstein JA, Scott CI Jr, Steinberg GK. Majewski osteodysplastic primordial dwarfism type II (MOPD II): expanding the vascular phenotype. Am J Med Genet A. 2010 Apr;152A(4):960-5. doi: 10.1002/ajmg.a.33252. (http://www.ncbi.nlm.nih.gov/pubmed/20358609?dopt=Abstract)
  • Hall JG, Flora C, Scott CI Jr, Pauli RM, Tanaka KI. Majewski osteodysplastic primordial dwarfism type II (MOPD II): natural history and clinical findings. Am J Med Genet A. 2004 Sep 15;130A(1):55-72. Review. (http://www.ncbi.nlm.nih.gov/pubmed/15368497?dopt=Abstract)
  • Rauch A, Thiel CT, Schindler D, Wick U, Crow YJ, Ekici AB, van Essen AJ, Goecke TO, Al-Gazali L, Chrzanowska KH, Zweier C, Brunner HG, Becker K, Curry CJ, Dallapiccola B, Devriendt K, Dörfler A, Kinning E, Megarbane A, Meinecke P, Semple RK, Spranger S, Toutain A, Trembath RC, Voss E, Wilson L, Hennekam R, de Zegher F, Dörr HG, Reis A. Mutations in the pericentrin (PCNT) gene cause primordial dwarfism. Science. 2008 Feb 8;319(5864):816-9. doi: 10.1126/science.1151174. Epub 2008 Jan 3. (http://www.ncbi.nlm.nih.gov/pubmed/18174396?dopt=Abstract)
  • Willems M, Geneviève D, Borck G, Baumann C, Baujat G, Bieth E, Edery P, Farra C, Gerard M, Héron D, Leheup B, Le Merrer M, Lyonnet S, Martin-Coignard D, Mathieu M, Thauvin-Robinet C, Verloes A, Colleaux L, Munnich A, Cormier-Daire V. Molecular analysis of pericentrin gene (PCNT) in a series of 24 Seckel/microcephalic osteodysplastic primordial dwarfism type II (MOPD II) families. J Med Genet. 2010 Dec;47(12):797-802. doi: 10.1136/jmg.2009.067298. Epub 2009 Jul 29. (http://www.ncbi.nlm.nih.gov/pubmed/19643772?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: January 2011
Published: December 16, 2014