Sjögren-Larsson syndrome ... (Sjögren-Larsson Syndrome) - Gen ALDH3A2.
The Sjögren-Larsson syndrome is a disorder characterized by dry, scaly skin, neurological and eye problems. These symptoms are evident in early childhood and generally do not worsen with age.
Affected children are often born prematurely. At birth the skin is erythematous, but later in childhood, becomes dry, rough and scaly, brownish or yellowish with tone. It is also common to find pruritus. These skin abnormalities are generally dispersed throughout the body, affecting more intensely the nape of the neck, back and limbs. The facial skin is usually not affected. Children with this disorder often show a delayed development of motor skills such as crawling and walking due to spasticity.
People with this condition may also have neurological signs and symptoms. Most affected individuals have leukoencephalopathy, intellectual disability, difficulties and delayed speech, seizures, small crystals in the retina, myopia or photophobia.
This process is due to mutations in the gene ALDH3A2, located on the short arm of chromosome 17 (17p11.2). This gene encodes an enzyme called aldehyde dehydrogenase lipid (FALDH). This enzyme is part of the oxidation process of fatty acids in fats are decomposed and converted into energy.
We found at least 80 mutations in the gene that cause ALDH3A2 Sjögren-Larsson syndrome of. Mutations in this gene disrupts the normal process of fatty acid oxidation. Most mutations result in the synthesis of an enzyme cleaving FALDH incapable of fatty aldehyde molecules. As a result, the fat can not be broken accumulate in cells, would interfere with the formation of cytoplasmic membranes of cells, and they can not control water loss. As a result, the skin has difficulty maintaining its balance water, causing dry and flaky skin. In the brain, the consequences of the accumulation of excess fat are unclear, but it is likely that the abundance of fat disrupts the formation of myelin. The lack of myelin can lead to neurological problems such as difficulty walking and intellectual disabilities.
This disease is inherited in an autosomal recessive pattern, that is, both copies of the gene in every cell must have mutations for alteration is expressed. The parents of an individual with an autosomal recessive disease have a copy of the mutated gene, but usually show no signs and symptoms of the disease.
Tests in IVAMI: in IVAMI perform detection of mutations associated with Sjögren-Larsson syndrome, by complete PCR amplification of the exons of the gene ALDH3A2, and subsequent sequencing.
Samples recommended: EDTA blood collected for separation of blood leukocytes, or impregnated sample card with dried blood (IVAMI may mail the card to deposit the blood sample).