Carpenter syndrome: marked variability of expression to include the Summitt and Goodman syndromes.

Here we report on two sibs with Carpenter syndrome showing marked intrafamilial variability. One patient had craniosynostosis of the sagittal suture, normal intelligence, and no abnormalities of hands and feet. The second patient had polysyndactyly of hands and feet, normal intelligence, and no craniosynostosis. The diagnosis of Carpenter syndrome was made after the second affected child in the family was born. This report emphasizes previous suggestions that acrocephalopolysyndactyly, type II, has variable clinical expression. It is suggested that polysyndactyly of feet is not an absolute requisite for the diagnosis of Carpenter syndrome. This allows the inclusion of Summitt and Goodman syndromes within the clinical spectrum of this disorder.