Chromosomal findings in the majority of cases of TRP II (or Langer-Giedion) syndrome and in some cases of TRP I syndrome lead to the conclusion that the former is due to a deletion extending from 8q24.11 to 8q24.13 whereas the latter is caused by an even smaller deleted segment, namely 8q24.12. A case of tricho-rhino-phalangeal syndrome type I with a mosaic deletion of band 8q24.12 is described.