Pfeiffer syndrome is an autosomal dominant craniosynostosis syndrome with characteristic anomalies of the hands and feet. Three clinical subtypes, which have important diagnostic and prognostic implications, have been identified. Type 1, the classic syndrome, is compatible with life and consists of craniosynostosis, midface deficiency, broad thumbs, broad great toes, brachydactyly, and variable syndactyly. Type 2 consists of cloverleaf skull with Pfeiffer hands and feet, together with ankylosis of the elbows. Type 3 is similar to type 2 but without cloverleaf skull. Ocular proptosis is severe, and the anterior cranial base is markedly short. Various visceral malformations have been found in association with type 3. Early demise is characteristic of types 2 and 3 (Cohen, 1993). Cohen and Barone (1994) further tabulated the findings in the 3 types of Pfeiffer syndrome.

Cloverleaf skull, or Kleeblattschaedel, consists of a trilobular skull with craniosynostosis. The condition shows pathogenetic variability and etiologic heterogeneity. The cause of isolated cloverleaf skull is unknown (Cohen, 2009). Cohen (1975) pointed out that Kleeblattschaedel is a component of many syndromes, e.g., it is found in some cases of Crouzon syndrome (123500), Pfeiffer syndrome (101600), and Carpenter syndrome (201000). Cohen (2009) listed 12 monogenic disorders with cloverleaf skull as a feature, including type II thanatophoric dysplasia (187601), which accounts for 40% of all cloverleaf skull syndromes. Cohen (2009) published photographs of cloverleaf skull in various syndromes.

Decreased fetal activity associated with multiple joint contractures, facial anomalies and pulmonary hypoplasia. Ultrasound examination may reveal polyhydramnios, ankylosis, scalp edema, and decreased chest movements (reflecting pulmonary hypoplasia).

The Al-Awadi/Raas-Rothschild/Schinzel phocomelia syndrome (AARRS) is a rare autosomal recessive disorder characterized by severe malformations of upper and lower limbs with severely hypoplastic pelvis and abnormal genitalia. The disorder is believed to represent a defect of dorsoventral patterning and outgrowth of limbs (summary by Kantaputra et al., 2010).