TELO2 and Global developmental delay: Another component of the TTT complex is encoded by TELO2, which is mutated in families with the newly described You–Hoover–Fong syndrome characterized by ID, microcephaly and short stature, global developmental delay with no regression of learned skills, dysmorphic facial features, abnormal movements, and disturbed vision and hearing (You et al., 2016; Moosa et al., 2017).