No causative gene has been found for idiopathic central precocious puberty; and FOXP2, located in 7q31, is the only known gene for speech and language disturbances. We report a girl with central precocious puberty, moderate mental retardation, and severe speech impairment; accompanied by a de-novo balanced translocation between 7q31 and 10p14. Physical mapping through molecular cytogenetic investigations demonstrated the breakpoints of 7q31 and 10p14 within a bacterial artificial chromosome (BAC) clone RP11-124G5 and a cosmid clone derived from a BAC clone RP11-1122C18, respectively. FOXP2 was found to be localized approximately 500 kb distant from the centromeric end of the disrupted BAC RP11-124G5 at the 7q31 breakpoint. Speech impairment in the girl might be derived from dysfunction of FOXP2 by a position effect of the 7q31 translocation breakpoint.