Babies born with Hunter syndrome almost always appear healthy at birth. Changes in facial features are often the first noticeable sign that something's not right.

Blood, urine or tissue samples can be checked for the deficient enzyme or for excess amounts of the complex sugar molecules associated with this disorder. A genetic analysis can confirm the diagnosis.

Because Hunter syndrome progresses slowly and its signs and symptoms overlap with a number of other disorders, definitive diagnosis may take some time.

Prenatal testing

Prenatal testing of the fluid that surrounds the baby (amniocentesis) or of a tissue sample from the placenta (chorionic villus sampling) can verify if your unborn child carries a copy of the defective gene or is affected with the disorder.