Myhre Syndrome

National Organization for Rare Disorders, Inc.

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It is possible that the main title of the report Myhre Syndrome is not the name you expected.

Disorder Subdivisions

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General Discussion

Myhre syndrome is an extremely rare genetic disorder characterized by short stature, unusual facial features, mild to moderate intellectual disability and various bone (skeletal) abnormalities. Characteristic facial features may include abnormally narrow skin folds (palpebral fissures) between the upper and lower eyelids (blepharophimosis), underdevelopment of the upper jaw bone (maxillary hypoplasia), and an unusually prominent jaw (prognathism). Other findings may include hearing impairment, short, stubby fingers and toes (brachydactyly), congenital heart defects, muscles that appear abnormally large (muscular pseudohypertrophy), joint stiffness, and narrowing (stenosis) of the voice box (larynx) and windpipe (trachea). Myhre syndrome is caused by mutations in the SMAD4 gene. All molecularly proven cases have been due to a de novo mutation (a new mutation that arises around the time of conception, not carried by the parents). A person with Myhre syndrome would have a 50-50 chance of transmitting this to each child.


Myhre syndrome was first described in the medical literature in 1981 by Drs. Myhre, Ruvalcaba and Graham. In 1998, Hopkin et al., reported on a condition that in 2002 would be termed (L)aryngotracheal stenosis (A)rthropathy, (P)rognathism, (S)hort stature syndrome or LAPS by Lindor et al. Researchers eventually learned that Myhre and LAPS syndromes were caused by mutations in the same gene and most likely are different expressions (variants) of the same disorder.

Supporting Organizations

Genetic and Rare Diseases (GARD) Information Center

PO Box 8126
Gaithersburg, MD 20898-8126
Tel: (301)251-4925
Fax: (301)251-4911
Tel: (888)205-2311

Little People of America, Inc.

250 El Camino Real Suite 201
Tustin, CA 92780
Tel: (714)368-3689
Fax: (714)368-3367
Tel: (888)572-2001

The Arc

1825 K Street NW, Suite 1200
Washington, DC 20006
Tel: (202)534-3700
Fax: (202)534-3731
Tel: (800)433-5255

For a Complete Report

This is an abstract of a report from the National Organization for Rare Disorders (NORD). For a full-text version of this report, go to and click on Rare Disease Database under "Rare Disease Information".

The information provided in this report is not intended for diagnostic purposes. It is provided for informational purposes only.

It is possible that the title of this topic is not the name you selected. Please check the Synonyms listing to find the alternate name(s) and Disorder Subdivision(s) covered by this report.

This disease entry is based upon medical information available through the date at the end of the topic. Since NORD's resources are limited, it is not possible to keep every entry in the Rare Disease Database completely current and accurate. Please check with the agencies listed in the Resources section for the most current information about this disorder.

Last Updated:  10/8/2015
Copyright  2015 National Organization for Rare Disorders, Inc.