Furthermore, loss-of-function mutations in four genes (PEX7, GNPAT, AGPS, and FAR1) that mediate peroxisomal synthesis of AAG, a necessary substrate for synthesis of plasmenyl-PE and plasmenyl-PC, result in rhizomelic chondrodysplasia punctata (RCDP) (39, 53, 54, 55, 56, 57). This evidence concerns the gene GNPAT and rhizomelic chondrodysplasia punctata.