Shoulder flexion, pulmonary function and glycosaminoglycan excretion. During ERT, shoulder flexion (degrees), pulmonary function (FVC) and urinary glycosaminoglycan (GAG) excretion were measured in patient 2 (● ) and patient 6 (■). Shoulder flexion: normal range 175–180. Pulmonary function (FVC) is expressed as a Z-score of the predicted value. GAG excretion: the dashed lines denote the normal value for age (115 μg/mg creatinine for patient 2, and 55 μg/mg creatinine for patient 6).