Translocation of 9q/13q resulting in duplication (trisomy 9pter leads to 9q22) and deficiency (monosomy 13pter leads to 13q12).

A profoundly retarded, 12-year-old female is described. Her phenotype is compatible with the clinical features of the trisomy 9p syndrome. Cytogenetic analyses showed her to be trisomic for 9pter leads to 9q22 and monosomic for 13pter leads to 13q12, as the result of adjacent-2 segregation during meiosis in her mother. The family pedigree shows this (9;13) translocation to be present in at least three generations.