Smith Lemli Opitz Syndrome

National Organization for Rare Disorders, Inc.

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It is possible that the main title of the report Smith Lemli Opitz Syndrome is not the name you expected.

Disorder Subdivisions

  • None

General Discussion

Smith-Lemli-Opitz syndrome (SLOS) is a variable genetic disorder that is characterized by slow growth before and after birth, small head (microcephaly), mild to moderate mental retardation and multiple birth defects including particular facial features, cleft palate, heart defects, fused second and third toes, extra fingers and toes and underdeveloped external genitals in males. The severity of SLOS varies greatly in affected individuals, even in the same family, and some have normal development and only minor birth defects. SLOS is caused by a deficiency in the enzyme 7-dehydrocholesterol reductase that results in an abnormality in cholesterol metabolism. SLOS is inherited as an autosomal recessive genetic 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

Smith-Lemli-Opitz/RSH Foundation

P.O. Box 212
Georgetown, MA 1833
Tel: (978)352-5885

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:  7/23/2007
Copyright  2007 National Organization for Rare Disorders, Inc.