Partly coinciding with this assumption, somatic gains of Xp or Xq were found in HB, and germline mutations in the X chromosome in X-linked disorders, such as Simpson–Golabi–Behmel syndrome and MECP2 duplication syndrome, were also found accompanying HB (Terracciano et al., 2003; Arthur Zimmermann, 2011). Here, MECP2 is linked to hemoglobin measurement.