Sanfilippo Syndrome
Sanfilippo Syndrome Causes
Sanfilippo syndrome is caused by the absence of enzymes that are necessary to break down the heparan sulfate sugar chain. The disease has 4 major forms, each of which affects a different enzyme. In its most severe form (Sanfilippo type A), patients have an altered form or are missing an enzyme called heparan N-sulfatase. The absence or alteration of alpha-N-acetylglucosaminidase is known as Sanfilippo type B. The lack of CoAlpha-glucosaminide acetyltransferase and N-acetylglucosamine 6-sulfatase are known as Sanfilippo C and Sanfilippo D, respectively. Sanfilippo syndrome is hereditary with an autosomal recessive pattern.
Sanfilippo Syndrome Definition
Sanfilippo syndrome pertains to a hereditary metabolism disorder characterized by the body's inability to properly break down complex sugar molecules called glycosaminoglycans. Sanfilippo syndrome belongs to a group of diseases called mucopolysaccharidoses (MPS), and is sometimes called MPS II.
Sanfilippo Syndrome Diagnosis
A physical exam may be done to screen for signs of spleen and liver swelling. An eye exam can also be done to determine clear corneas (as opposed to the cloudy corneas of Hurler syndrome patients). Urine tests are typically required to screen for elevated mucopolysaccharides in the urine. In addition, neurological tests can be done to identify signs of seizures and mental retardation. Other tests that can lead to a diagnosis of Sanfilippo syndrome include: echocardiogram, slit lamp eye exam, blood culture, bone x-rays, and skin fibroblast culture.
Sanfilippo Syndrome Symptoms and Signs
Symptoms of Sanfilippo syndrome typically appear after the first year of life. At ages 2 and 6, affected children usually begin to show a decline in learning ability. While growth will appear normal in the first few years of life, affected children will always have a lower-than-average height. Growth and development problems are followed by mental deterioration. In addition, affected children generally have coarse facial features, distinctly full lips, heavy eyebrows that meet in the middle of the face above the nose, as well as stiff joints that don't fully extend. Other symptoms include walking difficulties and diarrhea.
Sanfilippo Syndrome Treatment
Currently, there is no available treatment for Sanfilippo syndrome. Treatment of affected children remains largely supportive.