Height and head circumference. Male and female height (A-B) and head circumference (C-D) for age before and after HCT. The continuous thick black lines represent the nonlinear regression models for the post-HCT data. The continuous and dashed black lines represent the reference curves (+2 SD, 0 SD, and −2 SD) according to the WHO.²¹  The red crosses represent data of patients receiving TBI, the gray squares represent the target height. (E) Height expressed as SD score for age subdivided by the IDUA level; normal IDUA level vs IDUA level below the local lower reference limit. (F) Height expressed as SD score for age subdivided by the baseline height at HCT; −2 SD or higher vs lower than −2 SD.