Background: Mucopolysaccharidoses type I is a lysosomal storage disorder characterized by a deﬁciency of the lysosomal enzyme α l-iduronidase. It is an autosomal recessive condition with incidence of 1 case per 100 000 live births. MPS type I disorders characteristically present with dysmorphic features, growth failure, umbilical and/or inguinal hernia, a protruding abdomen, musculoskeletal disorder and cognitive impairment from an early age. The time period between the onset of symptoms and diagnosis remains prolonged and patients are still predominately diagnosed by enzyme activity tests.
Case: We reported a 7-year-old girl patient presented with stiffness and soreness in both hand. Since birth, the patient had corneal clouding and progressive vision impairment. She was unable to communicate effectively, developmental milestones delay and lost physical skills. There was no consanguineous in her parents. Radiologic finding with epiphyseal skeletal dysplasia. Confirmation of the diagnosis of MPS type I was accomplished by measuring blood spots with the MPS enzyme (MS/Ms Assay), which revealed a deficit of L-Iduronidase (0:08 uM/hr) (normal level >1.32 uM/hr) and Urinary glycosaminoglycan (GAG) concentration by DMB test showed elevated Heparan Sulfate and Dermatan Sulfate excretion in urine (7.56 mmol creatinine/L urine), 737.50 mg GAGs/L urine, 97.55mg GAGs/mmol creatinine (normal level 4.04) (1.22~8.758).
Conclusion: The combination of symptom and lack of disease awareness usually resulting in diagnostic delays. The early recognition of MPS type I is important for monitoring the chronic and progressive course of the disease and effective treatment with enzyme replacement which can decrease morbidity.