The importance of the minor spliceosome has been recently underscored by reports that mutations in U4atac cause microcephalic osteodysplastic primordial dwarfism type I (MOPD I) or Taybi-Linder syndrome (TALS) (Abdel-Salam et al., 2011; Edery et al., 2011; He et al., 2011). Here, RNU4ATAC is linked to microcephalic osteodysplastic primordial dwarfism type I.