A 6-year-old boy is brought to his pediatrician with profound mental retarda-
tion. Upon questioning the mother, several members of both the mother’s and
father’s family have had mental retardation. She also has noticed that he
appears very active and restless frequently getting into trouble in school. On
examination, the boy appears restless and his speech is significantly delayed
and incomprehensible. The boy has coarse facial features but otherwise has a
normal exam. Laboratory tests reveal an elevated level of heparan sulfate.
What is the most likely diagnosis?
What is the inheritance pattern of this disorder?
What are some other causes of mucopolysaccharidoses?