Infantile Sialic Acid Storage Disease, also known as ISSD, is a rare genetic disorder that affects the body's ability to break down and utilize sialic acid. Sialic acid is a type of sugar molecule that plays a crucial role in various biological processes, including cell communication and the development of the brain and nervous system.
Individuals with ISSD have a deficiency in a specific enzyme called sialin, which is responsible for transporting sialic acid out of the cells and into the bloodstream. As a result, sialic acid accumulates within the cells, leading to a wide range of symptoms and health problems.
Infants with ISSD typically exhibit developmental delay, intellectual disability, and severe neurologic manifestations. They may also have characteristic facial features, such as a small head size, a prominent forehead, and a flat nasal bridge. Furthermore, affected individuals may experience weak muscle tone (hypotonia), seizures, problems with coordination and movement, and impaired vision.
ISSD is an autosomal recessive disorder, meaning that an individual must inherit two copies of the defective gene, one from each parent, to develop the condition. The disease can be diagnosed through genetic testing that identifies mutations in the SLC17A5 gene, responsible for encoding the sialin protein.
Currently, there is no cure for ISSD. Treatment primarily involves managing the symptoms and providing supportive care to improve the quality of life for affected individuals. This may include physical therapy, speech therapy, and medications to control seizures. Ongoing monitoring and multidisciplinary medical care are essential to ensure the best possible outcomes for individuals with ISSD.
