A group of diseases characterized by craniofacial anomalies with dysmorphic facial features mainly resulting from premature craniosynostosis and by hand and foot anomalies most often consisting of brachy-, syn-, and polysyndactyly. A number of subtypes exist, but considerable phenotypic overlap occurs with experts now considering many of these syndromes to represent variants of the same disease. The classification into subtypes in the literature is conflicting. Furthermore, the Acrocephalosyndactyly and Acrocephalopolysyndactyly Syndromes have overlapping features and the classification, by many considered a pseudo-distinction, has been changed a few times since the first description.
Traditionally, Acrocephalosyndactyly Syndromes have been divided into four subtypes (Acrocephalosyndactyly Type IV has been eliminated):
Acrocephalosyndactyly Type I: Apert Syndrome
Acrocephalosyndactyly Type II: Crouzon Syndrome (most common; Oxycephaly-Acrocephaly; Virchow Oxycephaly)
Acrocephalosyndactyly Type III: Saethre-Chotzen Syndrome
Acrocephalosyndactyly Type V: Pfeiffer Syndrome