Mutations of the KIT (mast/stem cell growth factor receptor) proto-oncogene account for a continuous range of phenotypes in human piebaldism.
Piebaldism is a rare autosomal dominant disorder of pigmentation, characterized by congenital patches of white skin and hair from which melanocytes are absent. We have previously shown that piebaldism can result from missense and frameshift mutations of the KIT proto-oncogene, which encodes the cellular receptor tyrosine kinase for the mast/stem cell growth factor. Here, we report two novel KIT mutations associated with human piebaldism. A proximal frameshift is associated with a mild piebald phenotype, and a splice-junction mutation is associated with a highly variable piebald phenotype. We discuss the apparent relationship between the predicted impact of specific KIT mutations on total KIT-dependent signal transduction and the severity of the resultant piebald phenotypes.
Spritz
R A
RA
Department of Medical Genetics, University of Wisconsin, Madison 53706.
Holmes
S A
SA
Ramesar
R
R
Greenberg
J
J
Curtis
D
D
Beighton
P
P
D000595:Amino Acid Sequence; D001483:Base Sequence; D015139:Blotting, Southern; D005260:Female; D016368:Frameshift Mutation; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D010375:Pedigree; D010641:Phenotype; D016116:Piebaldism / Q000235:genetics*; D016133:Polymerase Chain Reaction; D011505:Protein-Tyrosine Kinases / Q000737:chemistry / Q000235:genetics*; D000090063:Proto-Oncogene Mas; D011518:Proto-Oncogene Proteins / Q000737:chemistry / Q000235:genetics*; D019009:Proto-Oncogene Proteins c-kit; D011519:Proto-Oncogenes; D011956:Receptors, Cell Surface / Q000737:chemistry / Q000235:genetics*
C000715470:MAS1 protein, human; D000090063:Proto-Oncogene Mas; D011518:Proto-Oncogene Proteins; D011956:Receptors, Cell Surface; D011505:Protein-Tyrosine Kinases; D019009:Proto-Oncogene Proteins c-kit