Recurrent lambdoid synostosis within two families.

We report on 2 families with multiple members who have proven or suspected lambdoid craniosynostosis. In one family the lambdoid suture was unilaterally involved in one sib, and bilaterally in the other. In the second family the propositus had unilateral lambdoid synostosis and his twin sisters each had bilateral lambdoid synostosis. Both families had another distant relative, a maternal grandmother in the first and paternal uncle in the second, who were also reported to have posterior plagiocephaly. We report these families as evidence for genetic transmission of a craniosynostotic trait which has only been rarely reported previously.