Sjogren-Larsson syndrome, a genetic condition, is typically marked by three main symptoms: ichthyosis (thickened, scaly skin resembling fish scales), spastic paraplegia affecting the legs, and mental retardation. The skin symptoms mirror those found in ichthyosiform erythroderma, which leads to red, scaly skin. Hyperkeratosis, or skin thickening, is common, and bruises (ecchymoses) may appear at or shortly after birth. Sweat glands function normally.The syndrome's spasticity can impact both arms and legs, leading to significant mobility challenges, with many patients never walking. Seizures occur in about half of those affected. Eye issues are also prevalent, with approximately 50% experiencing pigmentary degeneration of the retina, characterized by shimmering white dots. Individuals with this condition tend to be shorter than average.Research by Sjogren in 1956 and later by Sjogren and Larsson in 1957 suggested that all Swedish individuals with this syndrome might trace their ancestry to a single individual who experienced a genetic mutation around 600 years ago, a phenomenon known as the founder effect. This mutation is now found in about 1% of northern Sweden's population. The responsible gene is located on chromosome 17 (band 17p11.2). Carrying one copy of this gene is harmless, but if two carriers have a child, there is a 25% chance that the child will inherit the syndrome, as it follows an autosomal recessive inheritance pattern.Critical laboratory findings reveal a deficiency in the enzyme fatty aldehyde dehydrogenase 10 (FALDH10), which is central to the syndrome. The gene linked to this enzyme deficiency is the same as that for the syndrome. Dietary adjustments, such as reducing fat intake and adding medium-chain triglycerides, have shown some clinical benefits.Sjogren-Larsson syndrome has been identified in individuals from various ethnic backgrounds, including Swedes, Europeans, Arabs, and Native Americans, indicating genetic diversity. Despite this diversity, all mutations causing the syndrome involve changes in the FALDH gene. To differentiate it from another condition described by Swedish ophthalmologist Henrick Sjogren, this syndrome is sometimes referred to as T. Sjogren syndrome, named after Torsten Sjogren (1896-1974), a prominent psychiatrist, and Tage Larsson, a Swedish physician.The syndrome is also known by several other names, including ichthyosis, spastic neurological disorder, and oligophrenia syndrome, as well as fatty alcohol:NAD+ oxidoreductase deficiency, fatty aldehyde dehydrogenase deficiency, and fatty aldehyde dehydrogenase 10 deficiency.
