Morquio syndrome is inherited as an autosomal recessive genetic disorder; a person gets it when they inherit two copies of a mutated gene—one from each parent.
Here's a breakdown of the inheritance pattern:
-
Recessive Inheritance: This means that a person must have two copies of the mutated gene to develop Morquio syndrome. If they only have one copy, they are considered a carrier.
-
Carriers: Carriers don't have the disease themselves because the one normal copy of the gene is sufficient to produce enough of the necessary enzyme. However, they can pass the mutated gene on to their children.
-
Inheritance from Parents:
- If both parents are carriers, there is a 25% chance with each pregnancy that the child will inherit two copies of the mutated gene and develop Morquio syndrome.
- There is a 50% chance the child will inherit one copy and become a carrier.
- There is a 25% chance the child will inherit two normal copies and be neither affected nor a carrier.
-
New Mutations: In rare instances, Morquio syndrome can result from a de novo (new) mutation in a person with no family history of the condition. This is very uncommon.
In essence, to develop Morquio syndrome, an individual typically needs to inherit a mutated gene from both parents, who are usually carriers of the mutated gene but don't have the condition themselves.
