Hurler's Syndrome is a rare genetic disorder that causes a host of dreadful problems in the children it afflicts. Depending on the severity of the disease, it can cause growth problems (which lead to skeletal deformity and small stature), mental retardation, deafness, internal organ damage, and ultimately death in childhood or young adulthood.
This disease is also known in medical literature as mucopolysaccharidosis type 1 H, MPS disorder I H, MPS IH, gargoylism, lipochondrodystrophy, and Hurler disease.
It is a hereditary metabolic disorder caused by a recessive autosomal gene which results in a deficiency of the enzyme alpha-L-iduronidase. This enzyme breaks down dermatan sulfate and heparan sulfate, two types of mucopolysaccharides (complex carbohydrates). Consequently, the mucopolysaccharides accumulate in the cells of the body and cause damage to organs and tissues.
Symptoms include clouding of the corneas, skeletal deformities, stunted skeletal growth which leads to dwarfism, brain damage leading to mental retardation and death, severe coronary artery disease, heart defects, enlarged spleen and liver, deafness, and stiff joints, among other things. The disorder became called "gargoylism" because it frequently causes gross facial deformities that reminded people of the gargoyles on gothic cathedrals.
This disorder afflicts one out of every 10,000 children born. An afflicted child may seem normal at birth, but symptoms appear by the age of 1; in many cases, the first sign is an enlarged head. There are mild and severe forms of the syndrome:
- Scheie Syndrome is the milder form. Children who suffer from it have little to no mental retardation and usually survive into their young adulthood.
- Hurler-Scheie Syndrome is an intermediate form that afflicts some children; they usually die in adolescence.
- Hurler Syndrome is the severest form. Children with the severe form usually die from respiratory and cardiac failure before the age of ten.
There is presently no cure for any form of this disease, but stem cell transplants from donor bone marrow or umbilical cord blood can help some children. In the U.S. clinical trials for experimental enzyme replacement therapy are under way.
Hurler's Syndrome is one of a number of related rare genetic mucopolysaccharide disorders, the most common being Hunter's Syndrome.
The disorder was probably first described by a pediatrician named John Thompson in 1900. However, this version of mucopolysaccharidosis became named after a German researcher named Gertrud Hurler. She published a paper entitled "Uber einen Typ multipler Abartungen, vorwiegend am Skelettsystem" in 1919 that gave a fuller description of the syndrome.