Cleft palate in a rare case of Variant Klinefelter syndrome with 48,XXXY/46,XY mosaicism.

Variant Klinefelter syndrome with 48,XXXY/46,XY mosaicism has been rarely reported, and its phenotypic features, compared with those of the classic type, have not been well delineated. We describe a newborn baby with phenotypic abnormalities, including cleft palate and low-set ears. The cytogenetic analysis of peripheral blood lymphocytes showed a karyotype of 48,XXXY[36]/46,XY[4]. To the best of our knowledge, this is the first case in which 48,XXXY/46,XY mosaicism was related to the congenital anomaly of cleft palate. This case underscores that cytogenetic analysis should be a mandatory workup for the patient with cleft palate and that cleft palate may be a rare clinical presentation of the variant Klinefelter syndrome.