Notably, no variants were found in any of the genes previously associated with RSS (CDKN1C, IGF2, PLAG1, and HMGA2; OMIM #180860), Seckel syndrome (ATR, RBBP8, CENPJ, CEP152, CEP63, NIN, DNA2, TRAIP, NSMCE2; OMIM #21600) or Zellweger syndrome (PEX 1, PEX6, PEX12, PEX26, PEX10, PEX2, PEX5, PEX13, PEX16, PEX3, PEX19, PEX14, PEX11β; ΟΜΙΜ#214 100). This evidence concerns the gene PEX13 and microcephalic primordial dwarfism.