What is Hurler's Syndrome?

Hurler syndrome is a rare, inherited disease of metabolism in which a person cannot break down long chains of sugar molecules called glycosaminoglycans (formerly called mucopolysaccharides). Hurler syndrome belongs to a group of diseases called mucopolysaccharidoses, or MPS. See also: MPS II (Hunter syndrome) MPS IV (Morquio syndrome) MPS III (Sanfilippo syndrome) MPS I S (Scheie syndrome)

Alternative names
Alpha-L-iduronate deficiency; Mucopolysaccharidosis type I; MPS I H

Causes
Persons with Hurler syndrome do not make a substance called lysosomal alpha-L-iduronidase. This substance, called an enzyme, helps break down long chains of sugar molecules called glycosaminoglycans (formerly called mucopolysaccharides). These molecules are found throughout the body, often in mucus and in fluid around the joints. Without the enzyme, glycosaminoglycans build up and damage organs, including the heart. Symptoms can range from mild to severe. 

Hurler's Syndrome is a life threatening enzyme disorder. It is a rare disease that affects 1 out of 100,000 births and if not treated, a child with Hurler's can become blind, mentally retarded, stop walking and talking. This disease can also affect the lungs, heart, liver, kidney and brain.

Characteristics of a child with Hurler's include: a progressive curvature of the lower spine, significant shortening of stature, a short neck, stubby and claw-like hands, enlarged head, coarseness of the facial features with flattening of the bridge of the nose, wide nostrils, thick lips and a large protruding tongue. Children with the disorder also have thick hair and excessive body hair.

Hurler's children usually have different levels of developmental delays and their life expectancy is approximately 3 – 10 years of age