We identified a novel mutation in members of a family with signs of Crouzon syndrome and plagiocephaly. In affected members of the family an A-->G transition was found at position 886 in exon 5 of the fibroblast growth factor receptor 2 (FGFR2) gene. The base change results in the replacement of a lysine by glutamic acid in Ig-like loop III of FGFR2. The unusual finding of plagiocephaly in these Crouzon patients may either be the result of the type of mutation or because of genetic and environmental factors that affect the phenotype in addition to the mutated FGF receptor.