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

MPS 1 affected child with parents

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

Joint Stiffness in patients with MPS 1

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

Gibbus deformity in patients with MPS 1

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

Enzyme function test
  • Enzyme activity test9

    • Measures activity of α-L-iduronidase (IDUA) enzyme

    • Can confirm diagnosis

    • Can be measured in leukocytes, plasma, serum, or dried blood spots

DNA test
  • Genetic testing9

    • Identifies pathogenic variants in IDUA

    • Can confirm diagnosis

Urine GAG test
  • 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. 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. 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