Acrocephalopolysyndactyly, type Noack, in a large kindred

ACS was highly variable in this family. At least one affected member could have passed as uninvolved. Others could have been assigned to ACS types III, IV or V. The current classification is probably sound, but great caution is needed to assign individual cases of ACS to any group other than ACS types I or II or the Carpenter syndrome. The great variability of ACS has obvious implications for genetic counseling.