Seckel syndrome (MIM 210600 for SCKL1) is an autosomal recessive disorder characterized by intrauterine growth retardation, proportionate short stature, severe microcephaly, intellectual disability, and a typical facial appearance with a prominent and beaked nose, sloping forehead, and micrognathia (Seckel 1960; Majewski et al. Here, ATR is linked to microcephalic primordial dwarfism.