Sjögren–Larsson syndrome is an autosomal recessive form of ichthyosis apparent at birth.:485:564 Sjögren–Larsson syndrome (SLS) is a rare autosomal, recessive, neurocutaneous disease. This disease 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 spastic paraplegia which is characterized by leg spasms. The final identifier is mental retardation. The gene of SLS is 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 ¼ chance of getting the disease. In 1957 Sjogren and Larsson proposed that the Swedes with the disease all descended from a common ancestor 600 years ago. Today only 1% of Northern Sweden's population has this disease.
Sjögren, K. G. Torsten/Larsson, Tage K.: Oligophrenie in combination with congenital ichtyosis and spastic disorders. A clinical and genetic study, in: Acta psychiatrica et neurologica scandinavica, Copenhagen, 1957, 32, supplement 113, p. 9-105.