Late diagnosis of mucopolysaccharidosis type I in a girl with hand contractures

Overview

Introduction: Mucopolysaccharidosis type I (MPS I) belongs to the group of lysosomal storage diseases, the cause of which is an inherited disorder of an enzyme catalyzing catabolism of glycosaminoglycans, which accumulate in tissues. The disease manifests with varying severity and variability of clinical symptoms, that progress over time. Given the existence of targeted therapies, i.e. enzyme replacement therapy and hematopoietic stem cell transplantation, that prevent the development of the symptoms or significantly slow the progression of the disease, early diagnosis is crucial.

Method: We present a case study of a girl, who suffers from MPS I (m. Hurler-Scheie phenotype), without the typical coarse facial features, but has another characteristic symptom and thus hand contractures forming a „claw hand“, which developed at the beginning of the second year of life and required a surgical management. In addition, splenomegaly and a newly developed umbilical hernia were present.

Results: The diagnosis was established at the age of 4 years on the basis of a combination of biochemical and enzymological examinations, which were followed by confirmation at the molecular genetic level by detection of 2 pathogenic mutations of the IDUA gene. Enzyme replacement therapy with laronidase was initiated immediately. For a risk of further progression and development of neurological symptoms the hematopoietic stem cell transplantation was subsequently indicated.

Conclusion: A patient with MPS I may not always present with the chracteristic craniofacial dysmorphia, but other symptoms such as organomegaly, carpal tunnel syndrom and/or hand contractures have been described. Given the availability of laboratory diagnostics and targeted treatment, it is crucial for the patients to minimalize the time between the first signs of the disease and the diagnosis, because with each delay the patient’s health condition irreversibly worsens, and the therapy achieves satisfactory results only if initiated in time. Key words: lysosomal storage disorders, mucopolysaccharidosis type I (MPS I), m. Hurler-Scheie, glycosaminoglycans,
enzyme replacement therapy

Keywords:

Enzyme replacement therapy – lysosomal storage disorders – mucopolysaccharidosis type I (MPS I) – m. Hurler-Scheie – glycosaminoglycans