title: Down's syndrome. The possibility of a pathogenetic segment on chromosome no. 21.
mesh_terms: D002675:Child, Preschool; D002869:Chromosome Aberrations; D002904:Chromosomes, Human, 21-22 and Y; D004314:Down Syndrome / Q000209:etiology / Q000235:genetics*; D006570:Heterochromatin / Q000032:analysis; D006801:Humans; D008297:Male; D010641:Phenotype
chemical_list: D006570:Heterochromatin