Noonan syndrome and related disorders: dysregulated RAS-mitogen activated protein kinase signal transduction.
Noonan syndrome is a relatively common, genetically heterogeneous Mendelian trait with a pleiomorphic phenotype. Prior to the period covered in this review, missense mutations in PTPN11 had been found to account for nearly 50% of Noonan syndrome cases. That gene encodes SHP-2, a protein tyrosine kinase that plays diverse roles in signal transduction including signaling via the RAS-mitogen activated protein kinase (MAPK) pathway. Noonan syndrome-associated PTPN11 mutations are gain-of-function, with most disrupting SHP-2's activation-inactivation mechanism. Here, we review recent information that has elucidated further the types and effects of PTPN11 defects in Noonan syndrome and compare them to the related, but specific, missense PTPN11 mutations causing other diseases including LEOPARD syndrome and leukemias. These new data derive from biochemical and cell biological studies as well as animal modeling with fruit flies and chick embryos. The discovery of KRAS missense mutation as a minor cause of Noonan syndrome and the pathogenetic mechanisms of those mutants is discussed. Finally, the elucidation of gene defects underlying two phenotypically related disorders, Costello and cardio-facio-cutaneous syndromes is also reviewed. As these genes also encode proteins relevant for RAS-MAPK signal transduction, all of the syndromes discussed in this article now can be understood to constitute a class of disorders caused by dysregulated RAS-MAPK signaling.
Gelb
Bruce D
BD
Department of Pediatrics and Human Genetics, Mount Sinai School of Medicine, One Gustave Levy Place, Box 1040, New York, NY 10029, USA. bruce.gelb@mssm.edu
Tartaglia
Marco
M
D000818:Animals; D030801:Animals, Genetically Modified; D002642:Chick Embryo; D004330:Drosophila / Q000235:genetics; D011905:Genes, ras; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000737:chemistry / Q000235:genetics; D044542:LEOPARD Syndrome / Q000235:genetics / Q000378:metabolism; D020935:MAP Kinase Signaling System / Q000235:genetics*; D051379:Mice; D008954:Models, Biological; D008958:Models, Molecular; D009154:Mutation; D009634:Noonan Syndrome / Q000235:genetics* / Q000378:metabolism*; D011487:Protein Conformation; D054592:Protein Tyrosine Phosphatase, Non-Receptor Type 11; D017027:Protein Tyrosine Phosphatases / Q000737:chemistry / Q000235:genetics
D047908:Intracellular Signaling Peptides and Proteins; C516724:PTPN11 protein, human; D054592:Protein Tyrosine Phosphatase, Non-Receptor Type 11; D017027:Protein Tyrosine Phosphatases; C516725:Ptpn11 protein, mouse