ATR and microcephalic primordial dwarfism: Seckel syndrome is genetically heterogeneous, and mutations in DDR genes (ATRIP and ATR), DNA repair factors (NSMCE2, DNA2, TRAIP and CtIP) and components of the centrosome (NIN, CEP63, CEP152 and CENPJ) have been reported (Khetarpal et al., 2016).