| Sjögren–Larsson syndrome | |
|---|---|
| Other names | SLS |
 | |
| Two brothers (21 and 25 years old) with generalized dryness of skin with fine scales mainly around the umbilicus and in the flexural folds, one of Sjögren–Larsson syndrome characteristics. | |
| Specialty |
Medical genetics 
|
Sjögren–Larsson syndrome is a rare autosomal recessive form of ichthyosis with neurological symptoms. It can be identified by a triad of medical disorders. The first is ichthyosis, which is a buildup of skin to form a scale-like covering that causes dry skin and other problems. The second identifier is paraplegia which is characterized by leg spasms. The final identifier is intellectual delay.
SLS is caused by a mutation in the fatty aldehyde dehydrogenase gene found on chromosome 17. In order for a child to receive SLS both parents must be carriers of the SLS gene. If they are carriers their child has a 1⁄4 chance of getting the disease. In 1957 Sjögren and Larsson proposed that the Swedes with the disease all descended from a common ancestor 600 years ago. Today only 30–40 persons in Sweden have this disease.
Signs and symptoms
- Dry and scaly skin similar to all other ichtyosiforms (types of ichthyosis).
- Neurological problems – this can often cause mild paralysis in the legs
- Mild to moderate intellectual disability.
- Often associated ocular features, which include pigmentary changes in the retina.
The usual presentation of crystalline maculopathy is from the age of 1–2 years onwards.
Causes
It is associated with a deficiency of the enzyme fatty aldehyde dehydrogenase (ALDH3A2) which is encoded on the short arm of chromosome 17 (17p11.2). At least 11 distinct mutations have been identified.
Without a functioning fatty aldehyde dehydrogenase enzyme, the body is unable to break down medium- and long-chain fatty aldehydes which then build up in the membranes of the skin and brain.
This condition is inherited in an autosomal recessive pattern.
Diagnosis
Diagnosis is made with a blood test which sees if the activity of the fatty aldehyde dehydrogenase enzyme is normal.Gene sequencing can also be used, which can additionally be used by would-be parents to see if they are carriers.
Treatment
The ichthyosis is usually treated with topical ointment.Anti-convulsants are used to treat seizures and the spasms may be improved with surgery.
Eponym
It was characterized by Torsten Sjögren and Tage Konrad Leopold Larsson (1905–1998), a Swedish medical statistician. It should not be confused with Sjögren's syndrome, which is a distinct condition named after a different person, Henrik Sjögren.
See also
Further reading
- Sjögren, K. G. Torsten; Larsson, Tage K. (1957). "Oligophrenia in combination with congenital ichtyosis and spastic disorders; a clinical and genetic study". Acta Psychiatrica Scandinavica. Copenhagen. 32 (supplement 113): 9–105. doi:10.1111/j.1600-0447.1956.tb04725.x. PMID 13457946. S2CID 72058188.