Simpson Dysmorphia Syndrome

National Organization for Rare Disorders, Inc.

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

Disorder Subdivisions

  • None

General Discussion

Simpson dysmorphia syndrome types 1 and 2 are two forms of a rare, X-linked recessive, inherited disorder characterized by unusually large fetuses (prenatal overgrowth) and unusually large babies (postnatal overgrowth). In addition, affected individuals have characteristic facial features, more than two nipples (super-numerary nipples), and multisystemic malformations that may vary from child to child. Chief among these are cardiac malformations, mild to moderate mental retardation, cleft palate, and more than the five fingers and/or toes (polydactyly).

Symptoms associated with the more common form, Simpson dysmorphia syndrome type 1 (SDYS1), are less severe than those presented in SDYS2.

Individuals usually reach an above-average height. The general distinguishing features typically become less apparent in adulthood.

Supporting Organizations

Children's Craniofacial Association

13140 Coit Road
Suite 517
Dallas, TX 75240
Tel: (214)570-9099
Fax: (214)570-8811
Tel: (800)535-3643

FACES: The National Craniofacial Association

PO Box 11082
Chattanooga, TN 37401
Tel: (423)266-1632
Fax: (423)267-3124
Tel: (800)332-2373

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

NIH/National Institute of Arthritis and Musculoskeletal and Skin Diseases

Information Clearinghouse
One AMS Circle
Bethesda, MD 20892-3675
Tel: (301)495-4484
Fax: (301)718-6366
Tel: (877)226-4267

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:  5/27/2008
Copyright  2005 National Organization for Rare Disorders, Inc.