EXHIBIT A Agreement

EXHIBIT A

Agreement

The undersigned hereby agree that this statement on Schedule 13D with respect to beneficial ownership of shares of common stock of Genaissance Pharmaceuticals, Inc. is filed jointly, on behalf of each of them.

Dated: January 7, 2003

Capital Technologies CDPQ inc.

By: Xxxxx Xxxxxx
Name: Xxxxx Xxxxxx
Title: President

By: Xxxxxxx Xxxxxxxxx
Name: Xxxxxxx Xxxxxxxxx
Title: Corporate Secretary

Caisse de dépot et placement du Québec

By: Xxxxxx Xxxxxxxx
Name: Xxxxxx Xxxxxxxx
Title: Vice-President, Legal Affairs

By: Xxxxxxx Xxxxxxxxx
Name: Xxxxxxx Xxxxxxxxx
Title: Vice-President and Corporate
Secretary