Objective: To investigate the clinical characteristics and diagnosis of mucopolysaccharidosis VII.
Method: The clinical and biochemical features of an infant with mucopolysaccharidosis VII confirmed by enzyme assay were analyzed.
Result: The 2 month-old male infant showed hydrops fetalis, mental retardation, coarse face, corneal clouding, hepatosplenomegaly, hernias, Alder-Reilly granules in the leucocytes and decreased platelet (32 × 10(9)/L). The biochemical markers showed urinary glycosaminoglycans (GAG) (532.8 mg/L, controls < 70.0 mg/L). The ratio of GAG/creatinine was 161.3 (controls: 26.2 ± 11.7). Serum chitotriosidase activity was 315.8 nmol/(ml·h) [control < 53 nmol/(ml·h)]. Beta-glucuronidase activity was deficient in isolated leukocytes.
Conclusion: Severe form of mucopolysaccharidosis VII exhibited characteristics of hydrops fetalis, hepatosplenomegaly, coarse face, thrombocytopenia and Alder-Reilly granules in the leucocytes. The measurements of GAG in urinary and beta glucuronidase in leucocytes are critical to diagnosis and deferential diagnosis.