Study to Evaluate the Safety and Efficacy of Adalimumab in MPS I, II, and VI

Inclusion Criteria: * Male or female ≥5 years of age; * Diagnosis of MPS I, II or VI; * Treatment with ERT for ≥1 year or no treatment with ERT for ≥1 year; * Weight ≥15 kg; * Significant bodily pain reported by the CHQ-PF50 or SF-36 (\> 1 SD more severe \[below\] than the general population mean); * ≥ 3 joints with limitations in motion; and Patient or parent/legal guardian is able and willing to provide informed consent. For patients 7 to 17 years of age, assent must also be provided. Exclusion Criteria: * History of HCT less than 2 years prior to enrollment; * Immune suppression therapy less than 1 year prior to enrollment; * Active graft versus host disease; * Current diagnosis or history of lymphoma or other malignancy; * Current active infection; * History of serious opportunistic infection (e.g., bacterial \[Legionella and Listeria\]; tuberculosis \[TB\]; invasive fungal infections; or viral, parasitic, and other opportunistic infections); * Positive TB skin test, positive Quantiferon-TB Gold TB test, positive chest X-ray, or a recent exposure to TB * Congestive heart failure defined by an ejection fracture \<50% measured by ECHO; * Demyelinating disorders (e.g., central nervous system \[CNS\] disorders including multiple sclerosis and optic neuritis and peripheral nervous system disorders including Guillain-Barre syndrome); * Hematologic abnormalities (e.g., pancytopenia, aplastic anemia); * Hepatitis B infection (active or chronic carrier); * Latex sensitivity; * Pregnancy or breastfeeding; * Known or suspected allergy to adalimumab or related products; * Participation in simultaneous therapeutic study that involves an investigational study drug or agent within 4 weeks of study enrollment; * Requirement for live vaccine exposure that would be expected to occur during the time frame of the study; or * Any other social or medical condition that the Investigator believes would pose a significant hazard to the subject if the investigational therapy were initiated or be detrimental to the study.