eMedicine Specialties > Pediatrics: Genetics and Metabolic Disease > Metabolic Diseases

Mucopolysaccharidosis Type II: Follow-up

Author: Nancy E Braverman, MS, MD, Associate Professor, Department of Human Genetics, McGill University
Coauthor(s): Vinayak Kottoor, MD, Resident, Department of Genetics, McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University Hospital; Mary Kay Conover-Walker, MSN, PNP, Pediatric Nurse Practioner, Institute of Genetic Medicine, Johns Hopkins Hospital; Cydney L Fenton, MD, FAAP, Consulting Staff, Department of Pediatric Endocrinology, Children's Hospital Medical Center of Akron
Contributor Information and Disclosures

Updated: Jul 14, 2009

Follow-up

Further Outpatient Care

  • A Hunter Outcome Survey was established by Shire to better understand the variability and progression of Hunter syndrome (mucopolysaccharidosis type II [MPS II]) and to monitor long-term treatment effects of Elaprase.
  • The authors encourage patient participation to gather additional data regarding response to enzyme replacement therapy (ERT). Both patients receiving treatment and those who are not can participate. As of May 2007, 263 patients from 16 countries were enrolled; 24% were being treated with ERT.9
  • Annual follow-up includes the following:
    • Echocardiography and ECG
    • Pulmonary function tests
    • Liver and spleen volume (MRI)
    • Skeletal survey 
    • 6-minute walk test (every 6 mo) 
    • Quality of life and pain assessment 
    • Urinary glycosaminoglycan (GAG) level and iduronate sulfatase (IDS) antibody measurement
    • Audiography 
    • Baseline sleep study, repeated as needed 
    • CBC count, comprehensive metabolic panel, and routine urinalysis

Complications

Various complications may arise in the severe form of MPS II, including cardiac valvular disease and neurological complications33 .

  • Thickening of the tracheal walls may lead to obstructive airway disease.
  • As hepatosplenomegaly progresses, the abdominal wall becomes markedly distended, and hernias become more prominent.
  • All of the major joints, including the hips, knees, wrists, elbows, shoulders, and finger joints, become involved. This results in a decreased ability to pick up small objects, and, over time, walking becomes more difficult. The wrist is prone to carpal tunnel syndrome, which can further decrease hand function.
  • Boney involvement occurs in MPS II, which may lead to short stature.
  • The Hunter Outcome Survey noted that 33% of patients develop hypertension, and neurological involvement is reported in 84% of patients (mostly behavioral and cognitive abnormalities).9

Prognosis

  • The life expectancy for patients with the severe form (MPS IIA) is only about 10-15 years; however, those with the milder form (MPS-IIB) may live well into the seventh or eighth decades of life with supportive management.
  • After hematopoietic stem cell transplant, the characteristic cutaneous papules tend to regress, and most are gone by 3 months after the transplant.

Patient Education

Support groups can be a good source of information for families, some of which include the following:

Other sources of information include the following:

Miscellaneous

Medicolegal Pitfalls

  • Mucopolysaccharidoses (MPSs) represent a wide clinical spectrum of phenotypes that range from very mild to severe forms. The very mild forms of MPS I, II, and VI frequently cannot be differentiated based on clinical experience.
  • Pitfalls in the early diagnosis of mucopolysaccharidoses can be minimized if the appropriate laboratory studies are obtained and if the physician understands that these diseases are dynamic in nature.

Special Concerns

  • Prenatal testing can be performed using chorionic villus sampling or using cells collected via amniocentesis.
 
Acknowledgments

The authors and editors of eMedicine gratefully acknowledge the contributions of previous author William Rogers, MD, to the original writing and development of this article.



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Multimedia: Mucopolysaccharidosis Type II
References
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References

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Further Reading

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Keywords

mucopolysaccharidosis type II, Hunter syndrome, MPS II, type A MPS II, type B MPS II, iduronate sulfatase deficiency, lysosomal enzyme deficiency, dysostosis multiplex, lysosomal storage disorders, coarse facial features, corneal clouding, thickened skin, organomegaly, mental retardation, growth failure, skeletal dysplasia, upper airway obstruction, carpal tunnel syndrome, short stature, hyperactivity, progressive hearing loss, hepatomegaly, progressive retinal degeneration, recurrent ear infections, hydrocephalus

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Contributor Information and Disclosures

Author

Nancy E Braverman, MS, MD, Associate Professor, Department of Human Genetics, McGill University
Nancy E Braverman, MS, MD is a member of the following medical societies: Alpha Omega Alpha, American Society of Human Genetics, Society for Inherited Metabolic Disorders, and Society for the Study of Inborn Errors of Metabolism
Disclosure: Nothing to disclose.

Coauthor(s)

Vinayak Kottoor, MD, Resident, Department of Genetics, McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University Hospital
Disclosure: Nothing to disclose.

Mary Kay Conover-Walker, MSN, PNP, Pediatric Nurse Practioner, Institute of Genetic Medicine, Johns Hopkins Hospital
Mary Kay Conover-Walker, MSN, PNP is a member of the following medical societies: American Academy of Allergy Asthma and Immunology and Association of Clinical Research Professionals
Disclosure: Nothing to disclose.

Cydney L Fenton, MD, FAAP, Consulting Staff, Department of Pediatric Endocrinology, Children's Hospital Medical Center of Akron
Cydney L Fenton, MD, FAAP is a member of the following medical societies: American Academy of Pediatrics, American Diabetes Association, Endocrine Society, and Lawson-Wilkins Pediatric Endocrine Society
Disclosure: Nothing to disclose.

Medical Editor

Karl S Roth, MD, Professor and Chair, Department of Pediatrics, Creighton University School of Medicine
Karl S Roth, MD is a member of the following medical societies: Alpha Omega Alpha, American Academy of Pediatrics, American College of Nutrition, American Pediatric Society, American Society for Clinical Nutrition, American Society of Nephrology, Association of American Medical Colleges, Medical Society of Virginia, New York Academy of Sciences, Sigma Xi, Society for Pediatric Research, and Southern Society for Pediatric Research
Disclosure: MDS Pharma Salary Employment

Pharmacy Editor

Mary L Windle, PharmD, Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy, Pharmacy Editor, eMedicine
Disclosure: Pfizer Inc Stock Investment from financial planner; Avanir Pharma Stock Investment from financial planner ; WebMD Salary and stock Employment and investment from financial planner

Managing Editor

Margaret M McGovern, MD, PhD, Professor and Chair of Pediatrics, Stony Brook University, New York
Margaret M McGovern, MD, PhD is a member of the following medical societies: American Academy of Pediatrics and American Society of Human Genetics
Disclosure: Genzyme Grant/research funds PI

CME Editor

Daniel Rauch, MD, FAAP, Director, Pediatric Hospitalist Program, Associate Professor, Department of Pediatrics, New York University School of Medicine
Daniel Rauch, MD, FAAP is a member of the following medical societies: Ambulatory Pediatric Association, American Academy of Pediatrics, and Society of Hospital Medicine
Disclosure: Baxter Honoraria Consulting

Chief Editor

Bruce Buehler, MD, Professor, Department of Pediatrics, Pathology and Microbiology, Executive Director, Hattie B Munroe Center for Human Genetics, University of Nebraska Medical Center
Bruce Buehler, MD is a member of the following medical societies: American Academy for Cerebral Palsy and Developmental Medicine, American Academy of Pediatrics, American Association on Mental Retardation, American College of Medical Genetics, American College of Physician Executives, American Medical Association, and Nebraska Medical Association
Disclosure: Nothing to disclose.

 
 
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