Mosaicism for a small metacentric chromosome in a newborn with primary 21 trisomy (47,XY, + 21/48,XY, + 21, + mar).
D002869:Chromosome Aberrations; D025063:Chromosome Disorders; D004314:Down Syndrome; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D009030:Mosaicism