Möbius syndrome in a male with XX/XY mosaicism

Abstract

We report the case of a 2-year-old male with congenital symmetric facial diplegia, and bilateral paralysis of abduction of the eyes. Findings were compatible with a diagnosis of Möbius syndrome. Routine G-banded chromosome analysis revealed a mosaic karyotype with 40 cells showing normal 46,XX and 10 cells showing normal 46,XY. An XX male attributed to XX/XY mosaicism was diagnosed. The phenotype of our patient did not coincide with any described form of XX reversal syndrome, but and was a unique combination of both syndromes. The disorder of this patient is likely to represent a genetic condition with pleiotropic effects on brain development and sex determination, providing adding further evidence for the heterogeneity of Möbius syndrome and sex reversal syndromes.