Pai syndrome: report of seven South American patients

Frontonasal dysplasia is etiologically heterogeneous and various subsets are known. Pai syndrome is one subset, which is characterized by mild hypertelorism, midline cleft lip, nasal and facial polyps, pericallosal lipoma, ocular anomalies, and normal neuropsychological development. Here, we report seven South American patients and review earlier reported cases. The phenotype is clinically variable and five reported patients were severely affected. The cause of Pai syndrome is unknown to date. Several literature findings have been noted: nondiagnostic and discordant minor signs in a parent of two separate families with an affected child; discordant phenotype in monozygotic twins in one instance; and a de novo reciprocal translocation, 46,X,t(X;16)(q28;q11.2) in one instance.