Brief clinical report: unilateral partial tibia defect with preaxial polydactyly, general micromelia, and trigonomacrocephaly with a note on "developmental resistance".

We report a boy with predominantly unilateral severe tibia defect with a high grade of preaxial polydactyly. Family history suggests the possibility of autosomal dominant inheritance with reduced penetrance and quite variable expressivity. The boy's phenotype and other previously reported examples of predominantly unilateral involvement in autosomal dominant and autosomal recessive limb mutations strongly suggest a hypothesis of developmental resistance in the uninvolved parts.