Alexandre Reymond1,5, Valeria Marigo2,5, Murat B. Yaylaoglu3,5, Antonio Leoni2, Catherine Ucla1, Nathalie Scamuffa1, Cristina Caccioppoli2, Emmanouil T. Dermitzakis1, Robert Lyle1, Sandro Banfi2, Gregor Eichele3, Stylianos E. Antonarakis1 and Andrea Ballabio2,4

1Division of Medical Genetics*, University of Geneva Medical School and University Hospital of Geneva, Geneva, Switzerland

2TIGEM (Telethon Institute of Genetics and Medicine)*, Naples, Italy
3Max Planck Institute of Experimental Endocrinology*, Hannover, Germany
4Medical Genetics, Second University of Naples, Naples, Italy
5These authors equally contributed to this work
*These laboratories equally contributed to this work

Genome-wide expression analyses have a crucial role in functional genomics. High resolution methods, such as RNA in situ hybridization (ISH) provide an accurate description of the spatiotemporal distribution of transcripts as well as a 3-dimensional “in vivo” gene expression panorama. We set out to systematically analyze the expression patterns of genes from an entire chromosome and chromosome 21 was chosen because of the medical relevance of trisomy 21 (Down syndrome). We observed patterned expression in several tissues including those affected in trisomy 21 phenotypes. This high resolution expression “atlas” of an entire human chromosome is an important step towards the understanding of gene function and of the pathogenetic mechanisms in Down syndrome.

The study, which was supported financially in Switzerland by the Swiss National Science Foundation, the NCCR Frontiers in Genetics and the J. Lejeune and Childcare foundations, is published in the December 5th, 2002 issue of the prestigious international journal Nature (Vol: 420, pages 582-586, 2002). To download the pdf version of the paper.

A French and an English description of this work is provided. The entire set of data can be accessed through The site also recapitulates the importance of this work in the study of trisomy 21 and answers to frequently asked questions concerning Down syndrome (in English, French, Italian, German, Spanish, Dutch and Greek).