Here, we provide, to our knowledge, the first evidence of a role of FL-ATRX in the chromocenter clustering during neural differentiation, which allows us to hypothesize a contribution of this protein in MeCP2-mediated higher-order PCH organization in neurons, cells involved in the pathogenesis of both Rett [10] and ATR-X syndrome [60]. The gene discussed is MECP2; the disease is Alpha-thalassemia - X-linked intellectual disability syndrome.