Suspect and Refer Early
Diagnostic delays among patients with attenuated form of MPS I are common
Accurate early diagnosis is imperative to facilitate appropriate disease management.1,2

Average delay between symptom presentation and diagnosis1

Average delay between diagnosis and initiation of disease-specific management1
Tamara, living with MPS I

Some common symptoms of MPS I can be similar to the symptoms of other diseases3-8

Those are not all the symptoms of MPS I. Each patient may not have all the listed symptoms.
Diagnostic algorithm for patients with MPS I3

The presence of kyphosis and/or joint contractures, along with any combination of less specific symptoms, should prompt referral and/or diagnostic testing for MPS I
MPS I tests used for diagnostic process9

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Enzyme activity test9
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Measures activity of α-L-iduronidase (IDUA) enzyme
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Can confirm diagnosis
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Can be measured in leukocytes, plasma, serum, or dried blood spots
-

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Genetic testing9
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Identifies pathogenic variants in IDUA
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Can confirm diagnosis
-

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Urine GAG test9
- Accumulation of GAGs in lysosomes results in elevated GAGs in the urine
- May be qualitative or quantitative
- Urinary GAG measurement cannot confirm MPS I diagnosis but can be a helpful assessment in MPS I
GAG, glycosaminoglycan; IDUA, α-L-iduronidase; MPS, mucopolysaccharidosis
*Those are not all the symptoms of MPS I. Each patient may not have all the listed symptoms.
aUrinary GAGs testing to be done if available but without delaying the referral
References: 1. Beck M, Arn P, Giugliani R, et al. Genet Med. 2014;16(10):759-765. 2. Muenzer J, Wraith JE, Clarke LA, International Consensus Panel on the Management and Treatment of Mucopolysaccharidosis I. Pediatrics. 2009;123(1):19-29. 3. Tylki-Szymańska A, De Meirleir L, Di Rocco M, et al. Acta Paediatr. 2018;107(8):1402-1408. 4. Thatayatikom A, Modica R, De Leucio A. StatPearls [Internet]. StatPearls Publishing; 2022. Accessed March 21, 2022. https://www.ncbi.nlm.nih.gov/books/NBK554605/. 5. Bhavani GSL, Shah H, Shukla A, et al. In: Adam MP, Ardinger HH, Pagon RA, eds. GeneReviews® [Internet]. University of Washington, Seattle; 1993-2022. Accessed March 21, 2022. https://www.ncbi.nlm.nih.gov/books/NBK327267/. 6. Gupta V, Lee M. Indian J Endocrinol Metab. 2011;15(Suppl 2):S99-S106. 7. Krakow D. Clin Perinatol. 2015;42(2):301-19, viii. 8. Lorne C, Ellaway C, Foster HE, et al. J Inborn Errors Metab Screen. 2018;7:1-12. 9. Wraith JE. Expert Opin Pharmacother. 2005;6(3):489-506.
MAT-US-2205119-v1.0-10/2022 Last Updated: October 2022