title: Spontaneous fragility of an abnormally wide secondary constriction region in a human chromosome no. 9.
mesh_terms: D001345:Autoradiography; D002869:Chromosome Aberrations; D002906:Chromosomes, Human, 6-12 and X; D003582:Cytogenetics; D004314:Down Syndrome; D005260:Female; D006801:Humans; D007223:Infant; D007621:Karyotyping; D013936:Thymidine; D014316:Tritium
chemical_list: D014316:Tritium; D013936:Thymidine