Medical Definition of Hurler syndrome
A hereditary metabolic disorder, also designated mucopolysaccharidosis I, is caused by a recessive gene which results in a deficiency of the enzyme alpha-L-iduronidase, which breaks down dermatan sulphate and heparan sulphate, two types of mucopolysaccharides (complex carbohydrates). Consequently, the mucopolysaccharides accumulate in the cells of the body and cause damage.
It is characterised by coarse facies, corneal clouding, skeletal dysplasia, hepatosplenomegaly, hernias, mental retardation and early death.
There are mild and severe forms of the syndrome, the mild form is called Scheie Syndrome, the severe form is called Hurler syndrome, and children with an intermediate form have Hurler-Scheie syndrome. Patients with the severe form usually die from respiratory and cardiac failure before the age of ten. There is presently no cure.
Hurler syndrome is one of a number of related rare genetic mucopolysaccharide disorders, the most common being Hunter syndrome.
Diagnosis is possible by observing storage material in tissues, excretion of dermatan sulfate and heparan sulfate in urine, and deficient alpha-L-iduronidase activity in fibroblasts, amniocytes or other cell types.
Missense and other mutations, one of which is relatively common, have been identified in the gene.
Inheritance: autosomal recessive.
(29 Dec 1997)
Lexicographical Neighbors of Hurler Syndrome