<prompt> Answer this question truthfullyWhat does the term Pfeiffer syndrome refer to?  <response>: <reason> Pfeiffer syndrome is divided into three subtypes.Type 1 or classic Pfeiffer syndrome has symptoms as described above. Most individuals with type 1 have normal intelligence and a normal life span. Types 2 and 3 are more severe forms of Pfeiffer syndrome, often involving problems with the nervous system. Type 2 is distinguished from type 3 by more extensive fusion of bones in the skull, leading to a cloverleaf shaped head. 