Craniofacial features in Cohen syndrome: an anthropometric and cephalometric analysis of 14 patients.

Cohen syndrome (Mendelian Inheritance in Man [MIM] no. 216550) is a rare, autosomal-recessive inherited disorder with mental retardation and a typical appearance. The condition is relatively common in Finland where 35 patients have been diagnosed. We studied 22 patients in detail, obtaining anthropometric measurements of the head and face, and cephalometric radiographs of 14 patients (14-57 years of age). Measurements of patients were compared to population norms and matched controls. Anthropometric analysis confirmed and quantified the previously described syndrome features: small head size [-4 standard deviations (SD)], with varying cephalic index. Width of the upper face was close to normal, but width of the lower face was small. Philtrum length was shorter than in healthy controls (p = 0.0039 in females and p = 0.0014 in males). The measurements from standardized radiographs revealed short cranial base dimensions (-2.2 and -2.6 SD), but normal cranial base angles. Prognathism of jaws was within normal limits. Reduced head size (microcephaly), short philtrum and small cranial base dimensions are essential features in Cohen syndrome. In addition, most patients had forward-inclined upper incisors and maxillary prognathia. We conclude that exact measurements mostly confirmed the Cohen syndrome description based previously on clinical impression.