• Overview
• Inheritance
• Symptoms
  • Growth, Bones and Joints
  • Brain and Nerves
  • Physical Appearance
  • Ear, Nose, Throat and Chest
  • Heart
  • Liver, Spleen and Abdomen
  • Eyes
• Testing
• Treatment
• Resources
• Aldurazyme Update

Inheritance

Hurler syndrome is inherited in an autosomal recessive pattern (as are Hurler-Scheie and Scheie syndromes) and can affect both males and females. The disease occurs when both copies of a person's alpha-L-iduronidase gene have a mutation (a change in a gene which causes it to work incorrectly). Carriers have one normal gene copy and one gene copy with a mutation; carriers do NOT have Hurler syndrome. Being a carrier of Hurler syndrome is not known to lead to any health problems. About 1 in 150 people (less than 1%) are Hurler carriers.

A person with Hurler syndrome inherits one gene mutation from each parent, both of whom are carriers. Each child of two carrier parents has: a 25% chance of being unaffected and not a carrier (having two working copies of the gene), a 50% chance of being a Hurler carrier (having one working copy of the gene, like his/her parents), and a 25% chance of having Hurler syndrome (having no working copies of the gene.)

Blood relatives (siblings, aunts/uncles, cousins, etc.) of patients with Hurler syndrome may also be carriers of a Hurler gene mutation.

The different details of each family history will cause the risk figures and other genetic counseling issues to vary from family to family. The specific information for YOUR family will be covered during the genetic counseling consultation part of your evaluation at the Center.