Sjögren–Larsson syndrome
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 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.
- 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.
Causes
It is associated with a deficiency of the enzyme fatty aldehyde dehydrogenase which is encoded on the short arm of chromosome 17. 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.