Sjogren-Larsson Syndrome (SLS) is a hereditary condition marked by a trio of clinical symptoms: ichthyosis (fish-like thickened skin), spastic paraplegia (involving the legs), and . The skin manifestations resemble those of ichthyosiform erythroderma, a condition that causes red, scaly skin. Hyperkeratosis, or skin thickening, is commonly observed, and ecchymoses (bruising) appear at birth or shortly after in SLS cases. The spasticity can also affect the arms, contributing to spastic paraplegia. Significant intellectual disability is present, and most patients are unable to walk. About half of those affected experience seizures. Eye problems are part of the syndrome, with around 50% of cases showing pigmentary degeneration of the retina, characterized by glistening white dots.Individuals with SLS are often shorter than average. In 1956, Sjogren, and later Sjogren and Larsson in 1957, posited that all Swedish individuals with the syndrome descended from a single ancestor who experienced a genetic mutation approximately 600 years ago. This mutation is now found in at least 1% of northern Sweden's population, a phenomenon known as the founder effect. The SLS gene is located on chromosome 17, specifically at band 17p11.2. Carrying one copy of the gene (heterozygous) does not cause harm, but if two carriers have children, each child has a 25% chance of inheriting both SLS genes and developing the syndrome. Therefore, SLS is classified as an autosomal recessive disorder.Laboratory findings are crucial, revealing a deficiency in the enzyme fatty aldehyde dehydrogenase 10 (FALDH10) in SLS patients. This enzyme deficiency is responsible for the syndrome, and the SLS gene is synonymous with the FALDH10 gene. Some clinical improvements have been noted with dietary fat restriction and medium-chain supplementation.SLS affects individuals from various ethnic backgrounds, including Swedes and families of European, Arabic, and Native American descent, demonstrating genetic homogeneity; clinically identical diseases can result from diverse genetic mutations, all linked to changes in the FALDH gene.To distinguish it from another condition described by Swedish ophthalmologist Henrick Sjogren, SLS is sometimes referred to as T. Sjogren syndrome. Torsten Sjogren (1896-1974) was a notable figure in psychiatry at Stockholm's Karolinska Hospital, while Tage Larsson was also a Swedish physician. Alternative names for SLS include ichthyosis, spastic neurological disorder, oligophrenia syndrome, fatty alcohol: NAD+ oxidoreductase deficiency (FAO deficiency), and fatty aldehyde dehydrogenase 10 deficiency (FALDH10 deficiency).
