7 Bowen Bowen M E M E Boyden Boyden E D E D Holm Holm I A I A Loss-of-function mutations in PTPN11 cause metachondromatosis, but not Ollier disease or Maffucci syndrome Loss-of-function mutations in PTPN11 cause metachondromatosis, but not Ollier disease or Maffucci syndrome PLoS Genet PLoS Genet 2011 2011 7 7 04 04 e1002050 e1002050 21533187 21533187. This evidence concerns the gene PTPN11 and metachondromatosis.