Classification<unk>  is divided into three subtypes based on severity of symptoms. All three types result from an absence of, or insufficient levels of, the enzyme α-L-iduronidase.<unk>  H, or Hurler syndrome, is the most severe of the<unk>  subtypes. The other two types are<unk>  S (Scheie syndrome) and<unk>  H-S (Hurler-Scheie syndrome). Because of the substantial overlap between Hurler syndrome, Hurler-Scheie syndrome, and Scheie syndrome, some sources consider these terms to be outdated. Instead,<unk>  may be divided into "severe", "intermediate", and "attenuated" forms.
Mucopolysaccharidosis type I
GM1 gangliosidoses
GM2 gangliosidoses
GM2-gangliosidosis, AB variant
Glycogen storage disease type V
Glycogen storage disease type I
Glycogen storage disease type VI
Glycogen storage disease type 0