Mirror image duplications of chromosome 21. Three new cases and discussion of the mechanisms of origin.
D002869:Chromosome Aberrations / Q000235:genetics*; D025063:Chromosome Disorders; D002904:Chromosomes, Human, 21-22 and Y / Q000648:ultrastructure*; D004314:Down Syndrome / Q000235:genetics*; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male