chromosomes 21, trisomy 21, down syndrome. concept

ability abortion abstract arm background band blood cariotype cells chromosome chromosomes cognitive concept conceptual condition congenital copy dealing defect diagnostic disability disease disorder dna down duplication emblem extra facing fetal gen genetic giemsa handicap handicapped heart hindered hope individual life love lymphocytes medical meiosis mental microgenia mitosis physical prenatal presentation problem quad research scientific screen screening sign special staining support symbol syndrome test the tolerance translocation treatment trisomy white