Definition
Sjogren-Larsson syndrome is an inherited condition resulting in thickened, dry, rough skin (ichthyosis), mental retardation, and stiff, rigid muscles (spasticity). Although not all the manifestations of the disease may be immediately evident at birth, the disease is not considered to be progressive.
Description
Originally identified in Swedish patients, Sjogren-Larsson is a rare genetic disorder. The condition is more common in places where intermarriage within families is traditional, such as among the Haliwa Native Americans of Halifax and Warren counties in North Carolina, and in Vasterbotten and Norrbotten Counties in Sweden.
Demographics
The frequency of Sjogren-Larsson syndrome in the United States is unknown. In Sweden, 0.4 of every 100,000 babies is born with the condition. There is no increased association with a particular race or sex.
Causes and symptoms
Sjogren-Larsson syndrome is inherited in an autosomal recessive fashion, meaning that an affected child has received a faulty gene from both the mother and the father. The disorder has been traced to a variety of defects on chromosome 17, resulting in a defective or deficient enzyme called fatty aldehyde dehydrogenase and an inability to appropriately metabolize compounds called fatty alcohols. Fatty alcohols and fatty aldehydes accumulate and cause water loss from the skin, leading to the severely dry, thickened skin characteristic of the disease.
Most babies with Sjogren-Larsson syndrome are born prematurely. They often have noticeably reddened skin at birth (erythema), with fine scales evident. Over the course of the first year, the skin becomes increasingly dry, rough, scaly, and thickened. The skin is often itchy. Neurological signs become obvious when the child is late or completely misses reaching various developmental milestones (sitting, crawling, pulling to a stand, vocalizing). The muscles are stiff and rigid, prohibiting normal motor development. Some children are able to walk with braces, but others must rely on a wheelchair throughout life. Mild to moderate mental retardation also becomes evident over time. Language is usually quite delayed. About 40% of children with Sjogren-Larsson syndrome suffer from seizures. Other characteristics of people with Sjogren-Larsson syndrome include short stature, poor eyesight, sensitivity to light resulting in squinting, defective tooth enamel, coarse and brittle hair, curved spine (hunchback), and unusually widely-spaced eyes.
Diagnosis
Sjogren-Larsson syndrome can be diagnosed by demonstrating greatly decreased activity of the deficient enzyme, or by identifying one of the genetic defects known to cause Sjogren-Larsson syndrome. MRI of the brain will reveal problems with myelin, the whitish material that normally forms a sheath around nerves, allowing for quick conduction of nerve messages. Skin biopsies will reveal a variety of abnormalities characteristic of Sjogren-Larsson syndrome. An EEG (electroencephalogram) will reveal disordered electrical patterns throughout the brain.
Treatment team
A child with Sjogren-Larsson syndrome will usually require diagnostic and treatment help from a team of professionals, including a neurologist, orthopedic surgeon, dermatologist, and ophthalmologist. Most children with Sjogren-Larsson syndrome need to be placed in a special educational setting.
Treatment
There are no treatments that can cure Sjogren-Larsson syndrome. A number of lotion or cream preparations (including mineral oil, urea, and vitamin D-3) may help improve itching and flaking, decrease the speed of skin turnover, and soften the skin. Sauna treatments and frequent showering and bathing may improve moisture levels in the skin.
Spasticity is sometimes improved through various surgical procedures. Braces may help increase mobility.
Recovery and rehabilitation
Most children with Sjogren-Larsson syndrome will benefit from services by a physical therapist (to help improve mobility), occupational therapist (to help improve ability to attend to activities of daily living), and speech and language therapist (to help develop both receptive and expressive language).
Prognosis
People with Sjogren-Larsson syndrome will not be able to live independently. They will require care throughout their lives. They may live to an adult age. The disease is not progressive, so the level of disability identified will remain constant.
Special concerns
In families who have an increased risk of Sjogren-Larsson disease, prenatal diagnosis can be accomplished through amniocentesis, chorionic villi sampling, or fetal skin biopsy.
Resources
BOOKS
"Disorders of Keratinization." In Nelson Textbook of Pediatrics, edited by Richard E. Behrman, et al. Philadelphia: W. B. Saunders Company, 2004.
PERIODICALS
Haddad, F. S., M. Lacour, J. I. Harper, and J. A. Fixsen. "The orthopaedic presentation and management of Sjogren-Larsson syndrome." J Pediatr Orthop 19, no. 5 (September-October 1999): 617-19.
Lacour, M. "Update on Sjogren-Larsson syndrome." Dermatology 193, no. 2 (1996): 77-82
ORGANIZATIONS
Foundation for Ichthyosis & Related Skin Types, Inc. (F.I.R.S.T.). 650 N. Cannon Avenue, Suite 17, Lansdale, PA 19446. 215-631-1411; Fax: 215-631-1413. info@scalyskin.org. http://www.scalyskin.org/.
Rosalyn Carson-DeWitt, MD
