Ichthyosis, Sjögren Larsson Syndrome

Ichthyosis, Sjögren Larsson Syndrome

National Organization for Rare Disorders, Inc.

Important

It is possible that the main title of the report Ichthyosis, Sjögren Larsson Syndrome is not the name you expected. Please check the synonyms listing to find the alternate name(s) and disorder subdivision(s) covered by this report.

Synonyms

  • Ichthyosis, Spastic Neurologic Disorder, Mental Retardation
  • SLS

Disorder Subdivisions

  • None

General Discussion

Sjögren-Larsson syndrome is an inherited disorder characterized by scaling skin (ichthyosis), mental retardation, speech abnormalities, and spasticity. Affected infants develop various degrees of reddened skin with fine scales soon after birth. After infancy, the skin loses its redness and dark scales often appear on the neck and under the arms. Additionally, larger plate-like thick scales may develop on the lower legs. Developmental delay, speech abnormalities and seizures may accompany skin symptoms. Spasticity in the legs typically impairs motor ability and walking. Many children with this disorder have glistening white dots or degeneration of the pigment in the retina of the eye.

Symptoms

Symptoms of Sjögren-Larsson syndrome are usually evident at birth or during early infancy. This disorder is characterized by thickening of the skin (hyperkeratosis) with fine dry scales on most of the body associated with varying degrees of redness. After infancy, the flexural side of the arms and legs are affected by dark, scaly areas without redness.



In time, larger plate-like scales may appear on the skin's surface, particularly on the legs. The skin has an itchy characteristic. Speech abnormalities, mental retardation and seizures usually occur during the first 2 or 3 years of life. Glistening white dots in the back portion of the inside of the eyeball (retina) may be a specific sign of the disorder.



Patients with Sjögren-Larsson syndrome typically develop some degree of leg spasticity, resulting in difficulty walking or an inability to walk. Less commonly, patients have short stature, and curvature of the spine.

Causes

Patients with Sjögren-Larsson syndrome have a deficient activity of fatty aldehyde dehydrogenase (FALDH) and are unable to metabolize a certain type of fat called "fatty alcohol." Normally, fatty alcohol metabolism is important in the skin and brain, where it is used for the synthesis of membrane components.



Sjögren-Larsson syndrome is caused by mutations in the FALDH gene on the short arm of chromosome 17 (17p11.2). It is an inherited disorder transmitted in an autosomal recessive manner.



Chromosomes, which are present in the nucleus of human cells, carry the genetic information for each individual. Human body cells normally have 46 chromosomes. Pairs of human chromosomes are numbered from 1 through 22 and the sex chromosomes are designated X and Y. Males have one X and one Y chromosome and females have two X chromosomes. Each chromosome has a short arm designated "p" and a long arm designated "q". Chromosomes are further sub-divided into many bands that are numbered. For example, "chromosome 17p11.2" refers to a location on band 11 on the short arm of chromosome 17. The numbered bands specify the location of the thousands of genes that are present on each chromosome.



In recessive disorders the condition appears when the person inherits the same defective gene for the same trait from each parent. If the individual receives one normal gene and one gene for the disease, the person will be a carrier for the disease but will not show the condition. The risk of transmitting the disease to the children of a couple, both of whom are carriers for the recessive disorder, is approximately 25 percent per pregnancy.

Affected Populations

Sjögren-Larsson syndrome is a rare inherited disorder occurring in approximately 8.3 out of 100,000 persons in northern Sweden. It is less prevalent in the U.S. The disorder affects males and females in equal numbers.

Standard Therapies

The skin symptoms of Sjögren-Larsson syndrome can be treated by applying skin softening emollients. This can be especially effective after bathing while the skin is still moist. Lotions containing alpha-hydroxy acids can also be an effective treatment for the skin symptoms of this disorder. Anti-convulsant medication may control seizures. Physical therapy, speech therapy and special education services may be helpful.



Dietary restriction of fat (long chain fatty acids) and supplementation of medium chain fatty acids (triglycerides) has been associated with marked improvement in the skin symptoms in a few patients. In other patients, however, there has been no clinical response to dietary treatment.



Other treatment is symptomatic and supportive.

Investigational Therapies

Information on current clinical trials is posted on the Internet at www.clinicaltrials.gov. All studies receiving U.S. government funding, and some supported by private industry, are posted on this government web site.



For information about clinical trials being conducted at the NIH Clinical Center in Bethesda, MD, contact the NIH Patient Recruitment Office:



Tollfree: (800) 411-1222

TTY: (866) 411-1010

Email: prpl@cc.nih.gov



For information about clinical trials sponsored by private sources, contact:

www.centerwatch.com

References

TEXTBOOKS

Rizzo, W.B.: Sjögren-Larsson Syndrome: Fatty Aldehyde Dehydrogenase Deficiency. In The Metabolic and Molecular Bases of Inherited Disease. 8th Ed. Edited by Scriver, C.R., Beaudet, A.L., Valle, D., Sly, W.S., McGraw-Hill, New York, pp. 2239/2259, 2001.



JOURNAL ARTICLES

Rizzo, WB, Carney, G, and Lin, Z. The molecular basis of Sjögren-Larsson Syndrome: Mutation analysis of the fatty aldehyde dehydrogenase gene. Am J Hum Genet. 1999; 65: 1547- 1560.



Williams, ML, et al. Genetically Transmitted, Generalized Disorders of Cornification. The Ichthyoses. Dermatol Clin. January 1987; 5(1): 155-78.

Resources

Foundation for Ichthyosis & Related Skin Types

2616 N Broad Street

Colmar, PA 18915

Tel: (215)997-9400

Fax: (215)997-9403

Tel: (800)545-3286

Email: info@firstskinfoundation.org

Internet: http://www.firstskinfoundation.org



The Arc

1825 K Street NW, Suite 1200

Washington, DC 20006

Tel: (202)534-3700

Fax: (202)534-3731

Tel: (800)433-5255

TDD: (817)277-0553

Email: info@thearc.org

Internet: http://www.thearc.org



NIH/National Institute of Arthritis and Musculoskeletal and Skin Diseases

Information Clearinghouse

One AMS Circle

Bethesda, MD 20892-3675

USA

Tel: (301)495-4484

Fax: (301)718-6366

Tel: (877)226-4267

TDD: (301)565-2966

Email: NIAMSinfo@mail.nih.gov

Internet: http://www.niams.nih.gov/



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

TDD: (888)205-3223

Internet: http://rarediseases.info.nih.gov/GARD/



European Network for Ichthyosis (ENI)

In den Dellen 21

D-51515 Kürten

Germany

Tel: +49 2207849869

Email: e-n-i@gmx.net

Internet: http://www.ichthyosis.eu



For a Complete Report

This is an abstract of a report from the National Organization for Rare Disorders, Inc.® (NORD). Cigna members can access the complete report by logging into myCigna.com. For non-Cigna members, a copy of the complete report can be obtained for a small fee by visiting the NORD website. The complete report contains additional information including symptoms, causes, affected population, related disorders, standard and investigational treatments (if available), and references from medical literature. For a full-text version of this topic, see http://www.rarediseases.org/search/rdblist.html.

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