In the severe form (Hurler syndrome or MPS I-H; see this term) skeletal deformities and a delay in motor and intellectual development are the leading symptoms.

Patients with the intermediate form (Hurler-Scheie syndrome or MPS I-H/S; see this term) have normal or almost normal intelligence, but exhibit various degrees of physical impairment.

Hurler-Scheie syndrome is not as severe as Hurler syndrome, but more severe than Scheie syndrome.

Prevalence is estimated at 1/100,000, with Hurler syndrome accounting for 57% of cases, Hurler-Scheie syndrome accounting for 23% of cases and Scheie syndrome accounting for 20% of cases.

Prevalence is estimated at 1/100,000, with Hurler syndrome accounting for 57% of cases, Hurler-Scheie syndrome accounting for 23% of cases and Scheie syndrome accounting for 20% of cases.

Hurler syndrome (MPS 1-H) represents the most severe form of mucopolysaccharidosis.

There are three variants, differing widely in their severity, with Hurler syndrome being the most severe, Scheie syndrome the mildest and Hurler-Scheie syndrome giving an intermediate phenotype.

The prevalence of MPS I has been estimated at 1/100,000, with Hurler-Scheie syndrome accounting for 23% of cases or a prevalence of approximately 1/435,000.

Hunter syndrome or mucopolysaccharidosis II is a rare genetic disease that occurs when an enzyme that the body needs is either missing or malfunctioning.