Hurler Syndrome

Hurler syndrome is the most severe form of MPS1, a rare lysosomal storage disorder that is marked by skeletal deformities, cognitive impairment, heart disease, respiratory issues, enlarged liver and spleen, distinctive facies, and decreased life expectancy.

Inherited mucopolysarcharidosis type I (MPS I) is an uncommon condition. The Hurler syndrome is another name for MPS I. Many bodily systems are impacted in children with Hurler syndrome due to an abnormal buildup of complex carbohydrates in their cells. Currently, the subtypes of Hurler syndrome are classified as “severe” and “attenuated” (less severe). One of around 50 illnesses categorized as lysosomal storage disorders is Hurler syndrome (LSD). Genetic anomalies in these diseases prevent lysosomes from functioning normally in human cells.

Causes of Hurler syndrome

Hurler syndrome is brought on by a change in the IDUA gene, which encodes for the creation of the particular enzyme alpha-L-iduronidase. The lysosomes of cells typically include this specific protein, which aids in the breakdown of complex sugars known as glycosaminoglycans (GAGs). Alpha-L-iduronidase deficit or full absence is caused by genetic abnormalities in the IDUA gene, which leads to an aberrant buildup of GAGs in the body’s cells.

Affected children receive one faulty copy of the IDUA from each parent because this issue is hereditary and is inherited in an autosomal recessive form.

Symptoms of Hurler syndrome

The less severe variant of MPS I may not manifest any symptoms or signs in newborns at delivery. Those who have severe MPS I may exhibit clinical signs at birth.

Each symptom has a range. Some kids simply experience a few, minor symptoms. Significant disease problems affect other children.

Symptoms may include:

• clouding of the front part of the eye (corneal clouding)
• frequent upper respiratory infections
• enlarged tonsils and/or adenoids
• distinct facial features (coarse facial features)
• hernias

Other symptoms children might experience over time include:

• thickening and dysfunction of the heart valves
• abnormal curvature of the spine (scoliosis, kyphosis)
• enlargement of the liver and spleen (hepatosplenomegaly)
• accumulation of fluid around the brain (hydrocephalus)
• compression of the spinal cord
• progressive neurological decline

1. Any structural abnormality of a cardiac valve.
2. An abnormality of one or more of the vertebrae.
3. An abnormality of the skeletal system.
4. An abnormality of the tonsils.

Treatment of Hurler syndrome

Current approaches to Hurler syndrome are tailored to specific patients and may include enzyme replacement therapy, bone marrow transplant, hematopoietic stem cell transplant and targeted symptom management. Treatment plans require interdisciplinary collaboration and depend greatly on your child’s age and specific disease presentation.