Meiotic evidence in Down's syndrome for 21/21 chromosome translocation or isochromosome.
D000293:Adolescent; D001706:Biopsy; D002869:Chromosome Aberrations; D002904:Chromosomes, Human, 21-22 and Y; D004314:Down Syndrome / Q000235:genetics*; D006801:Humans; D008297:Male; D008540:Meiosis; D013737:Testis / Q000166:cytology