1. Langdon-Down, J. Observations on an ethnic classification of idiots. London Hospital Reports 3, 259–262 (1866). First description of the phenotype of DS.
2. LeJeune, J., Gautier, M. & Turpin, R. Etudes des chromosomes somatiques de neufs enfants mongoliens. C. R. Hebd Seances Acad. Sci. 248, 1721–1722 (in French) (1959). Identification of the extra chromosome as the genomic cause of DS.
3. Davisson, M. T., Schmidt, C. & Akeson, E. C. Segmental trisomy of murine chromosome 16: a new model system for studying Down syndrome. Prog. Clin. Biol. Res. 360, 263–280 (1990). Description of the most widely used mouse model of DS.
4. Hattori, M. et al. The DNA sequence of human chromosome 21. Nature 405, 311–319 (2000). The landmark paper on the sequence of the long arm of chromosome 21.
5. Antonarakis, S. E. 10 years of genomics, chromosome 21, and Down syndrome. Genomics 51, 1–16 (1998).