Your browser does not support javascript:   Search for gard hereSearch for news-and-events here.

Diseases

Genetic and Rare Diseases Information Center (GARD)

Print friendly version

Microcephalic osteodysplastic primordial dwarfism type 1


Other Names for this Disease
  • Brachymelic primordial dwarfism
  • Cephaloskeletal dysplasia
  • Low-birth-weight dwarfism with skeletal dysplasia
  • Microcephalic osteodysplastic primordial dwarfism types 1 and 3
  • MOPD 1
More Names
See Disclaimer regarding information on this site. Some links on this page may take you to organizations outside of the National Institutes of Health.


Your Question

Do you have information on MOPD Type I that I could share with a family I know?

Our Answer

We have identified the following information that we hope you find helpful. If you still have questions, please contact us.

What is microcephalic osteodysplastic primordial dwarfism type 1 (MOPD1)?

Microcephalic osteodysplastic primordial dwarfism type 1 (MOPD1) is a genetic condition that is mainly characterized by intrauterine and post-natal growth retardation; an abnormally small head size (microcephaly); abnormal bone growth (skeletal dysplasia); distinctive facial features; and brain anomalies. Other signs and symptoms include sparse hair and eyebrows; dry skin; short limbs; dislocation of the hips and elbows; seizures; and intellectual disability.[1] It is caused by mutations in the RNU4ATAC gene and is inherited in an autosomal recessive manner.[2] Treatment is supportive only. The prognosis is poor with most affected individuals dying within the first year of life.[1] MOPD types 1 and 3 were originally thought to be separate entities, but more recent reports have confirmed that the two forms are part of the same syndrome.[1]
Last updated: 11/11/2011

What causes microcephalic osteodysplastic primordial dwarfism type 1 (MOPD1)?

Microcephalic osteodysplastic primordial dwarfism type 1 (MOPD1) has been shown to be caused by mutations in the RNU4ATAC gene.[2]
Last updated: 11/11/2011

How is microcephalic osteodysplastic primordial dwarfism type 1 (MOPD1) inherited?

MOPD1 is thought to be inherited in an autosomal recessive manner.[3] This means that affected individuals have abnormal gene changes (mutations) in both copies of the disease-causing gene, with one copy inherited from each parent. The parents who each carry one abnormal copy of the gene are referred to as carriers; carriers typically do not show signs or symptoms of an autosomal recessive condition. When two carriers have children, each child has a 25% (1 in 4) risk to have the condition, a 50% (1 in 2) risk to be a carrier like each of the parents, and a 25% chance to not have the condition and not be a carrier.
Last updated: 11/11/2011

How might microcephalic osteodysplastic primordial dwarfism type 1 (MOPD1) affect pregnancy?

Little data is available regarding how MOPD1 affects pregnancy. Both uncomplicated full-term pregnancies and pre-term pregnancies with complications have been reported in the medical literature.[4][5] Consistently, however, ultrasound evaluations show that the baby is not growing as quickly as he or she should.[3]

Pregnancies associated with complications and those where the baby has been diagnosed prior to birth with a medical condition, are considered high risk. Women with high risk pregnancies need a special health care team to monitor their pregnancy. Click here to view an information page about choosing a pregnancy health care team.

Last updated: 9/26/2013

What are the signs and symptoms of microcephalic osteodysplastic primordial dwarfism type 1 (MOPD1)?

Individuals with MOPD1 may have low birth weight, growth retardation, short limbs, broad hands, small head size (microcephaly), abnormal bone growth (skeletal dysplasia) and a distinct facial appearance. Facial characteristics may include a sloping forehead; protruding eyes; prominent nose with a flat nasal bridge; and small jaw (micrognathia).[3][1] In addition, babies with MOPD1 may experience short episodes of stopped breathing (apnea) and seizures.[3] Affected individuals also commonly have sparse hair and eyebrows; dry skin; dislocation of the hips or elbows; and intellectual disability.[1] Brain abnormalities that have been reported include lissencephaly, hypoplastic (underdeveloped) frontal lobes, and agenesis of the corpus callosum or cerebellar vermis (the nerve tissue that connects the two halves of the cerebellum).[1]
Last updated: 11/11/2011

How does microcephalic osteodysplastic primordial dwarfism type 1 (MOPD1) affect development and learning?

Infants with MOPD1 are often born with severe brain abnormalities, such as lissencephaly and agenesis of the corpus callosum.[1] They have decreased development of both mental and motor skills and seizures are common.[3]
Last updated: 9/26/2013

What is the prognosis for people with microcephalic osteodysplastic primordial dwarfism type 1 (MOPD1)?

Prognosis can vary from patient to patient, however it is generally poor. Some babies are stillborn. Most infants pass away with in a year, often due to infectious diseases.[3]
Last updated: 9/26/2013

How might microcephalic osteodysplastic primordial dwarfism type 1 (MOPD1) be treated?

At this time there are no specific treatments for MOPD1. Treatment is generally supportive. The prognosis is poor for affected individuals, with most of the reported patients dying within the first year of life.[1]
Last updated: 11/11/2011

What are the chances that future children with be born with microcephalic osteodysplastic primordial dwarfism type 1 (MOPD1)?

When two carriers of an autosomal recessive condition have children, each child has a 25% (1 in 4) risk to have the condition, a 50% (1 in 2) risk to be a carrier like each of the parents, and a 25% chance to not have the condition and not be a carrier.

To learn more about the specific risks to your future offspring, we recommend that you speak with a genetics professional. To find a genetics clinic near you, we recommend contacting your primary doctor for a referral.

To find a genetics clinic, we recommend that you contact your primary doctor for a referral. Learn more about genetic consultations.

The following online resources can also help you find a genetics professional in your community:

  • GeneTests offers a searchable directory of U.S. and international genetics and prenatal diagnosis clinics.
  • The National Society of Genetic Counselors provides a database of genetics counseling services, searchable by location, name, institution, type of practice, or specialty.
  • The University of Kansas Medical Center provides a list of links to genetic centers and clinics, associations, and university genetics departments.
  • The American College of Medical Genetics has a Genetics Clinics Database for individuals who wish to locate a U.S. genetics center.
  • The American Society of Human Genetics (ASHG) is a professional organization of researchers and clinical geneticists. The ASHG maintains a database of its members, some of whom live outside of the United States. Visit the ASHG site if you are interested in obtaining a list of the geneticists in your country, though some may be researchers only and may not offer medical care.
Last updated: 9/26/2013

References
  • Microcephalic osteodysplastic primordial dwarfism types 1 and 3. Orphanet. November 2008; http://www.orpha.net/consor/cgi-bin/OC_Exp.php?lng=EN&Expert=2636. Accessed 11/11/2011.
  • Ada Hamosh. MICROCEPHALIC OSTEODYSPLASTIC PRIMORDIAL DWARFISM, TYPE I; MOPD1. OMIM. April 22, 2011; http://omim.org/entry/210710. Accessed 11/11/2011.
  • Spranger JW, Brill PW, Poznanski A. Bone Dysplasias: An atlas of genetic disorders of the skeletal development. 2nd ed. Oxford, NY: Oxford University Press; 2002;
  • Eason J, Hall CM, Trounce JQ. Renal tubular leakage complicating microcephalic osteodysplastic primordial dwarfism. J Med Genet. 1995;
  • Meinecke P, Passarge E. Microcephalic osteodysplastic primordial dwarfism type I/III in sibs. J Med Genet. 1991;