Progression of Polysomnographic Abnormalities in Mucolipidosis II (I-Cell Disease) Progression of Polysomnographic Abnormalities in Mucolipidosis II (I-Cell Disease) Download A Snapshot in Time: Subjective-Objective Discrepancies during In-Lab Polysomnography A 14-Year-Old Girl with Excessive Daytime Sleepiness and Facial Twitching