Hemifacial microsomia in a patient with Klinefelter syndrome.

A patient with 47, XXY karyotype, Klinefelter Syndrome, and hemifacial microsomia (unilateral microtia and mandibular hypoplasia) is described. In view of the fact that this is the second reported patient with hemifacial microsomia and a sex chromosomal abnormality, the relationship of these two findings is discussed. Appropriate diagnostic work-up of the patient with hemifacial microsomia is reviewed.