title: Duplication 9p due to unequal sister chromatid exchange.
abstract: A case of trisomy 9p syndrome is reported. The karyotype showed a tandem duplication of the short arm and of the inverted heterochromatic block of chromosome 9. Unequal sister chromatid exchange seems to be the only possible cause of this finding.
mesh_terms: D002871:Chromosome Banding; D002899:Chromosomes, Human, Pair 9; D005260:Female; D006801:Humans; D007621:Karyotyping; D010375:Pedigree; D012854:Sister Chromatid Exchange; D014314:Trisomy