INHERITANCE OF MPS I
MPS I is a genetic condition caused by disease-causing changes in the IDUA gene, which leads to deficiency of the IDUA enzyme.
![A girl sitting in a park diagnosed with a genetically inherited MPS I disease](/dam/jcr:967164e5-b7b8-4b81-b3d7-009abb4727fa/Patient%20image_Anisa.png 290w)
MPS I is a genetic condition. This means MPS I can be passed down through families. People may get it when both parents have changes in the IDUA gene.
Can MPS I affect other family members?
![25% share](/dam/jcr:21a59668-a339-4fe4-9c73-3d3fbec6471c/MPS%20I%20affect_icon_01@2x.png 260w)
chance of being affected
![50% share](/dam/jcr:ddefaaf7-94f1-4604-bb32-29157cff7f0e/MPS%20I%20affect_icon_02.png 130w)
chance of being an unaffected carrier, like each parent
![25% share](/dam/jcr:21a59668-a339-4fe4-9c73-3d3fbec6471c/MPS%20I%20affect_icon_01@2x.png 260w)
chance of being unaffected and not a carrier of the altered IDUA gene at all
So, that means that if both parents are carriers of MPS I, there is a 1 in 4 or 25% chance for each of their children to inherit the condition.
For each pregnancy, the chances of a baby inheriting MPS I are completely independent of whether a previous child was affected by MPS I.
MPS I is caused by disease-causing changes in the IDUA gene and is inherited in an autosomal recessive pattern. People with 2 copies of the altered IDUA gene would have MPS I. People with only one copy of the altered IDUA gene do not have MPS I; they are called carriers, and they can pass that altered gene to their children. MPS I affects males and females equally. If both parents carry one copy of the altered gene (which means they both are carriers), each of their children has a:
How MPS I is passed on from parents to children
![Hierarchy of inheritance pattern of MPS I](/dam/jcr:4efd2b6e-90c8-41bd-9338-0fd1b46fc2fb/Inheritance%20of%20MPS%20I_image@2x%20(1).png)
People in families who have MPS I consider being tested
Since MPS I is genetic, when you or someone in your family has MPS I, it is important that other family members learn about this so they may get tested for MPS I. A genetic counselor is someone who can help you find out if any other member of the family should test for MPS I.
IDUA, α-L-iduronidase; MPS I, mucopolysaccharidosis type I.