X0303 4 2011-04-04 0000732485 GENZYME CORP GENZ 0001052622 WHITWORTH RALPH V 12400 HIGH BLUFF DR. #600 SAN DIEGO CA 92130 1 Genzyme common stock (GENZ) 2011-04-04 4 M 0 2375.0000 0.0000 A 4750.0000 D Genzyme common stock (GENZ) 2011-04-04 4 D 0 2375.0000 74.0000 D 2375.0000 D Genzyme common stock (GENZ) 2011-04-04 4 U 0 10606248.0000 74.0000 D 0.0000 I see footnotes (1) and (2) Restricted Stock Units 0.0000 2011-04-04 4 M 0 2375.0000 0.0000 D 2011-06-16 Genzyme common stock (GENZ) 2375.0000 0.0000 D Stock Option (right to buy) 52.6600 2011-04-04 4 D 0 7125.0000 51.5200 D 2010-06-16 2020-04-14 Genzyme common stock (GENZ) 7125.0000 0.0000 D Stock Option (right to buy) 51.5200 2011-04-04 4 D 0 7125.0000 52.6600 D 2011-06-16 2020-06-16 Genzyme common stock (GENZ) 7125.0000 0.0000 D The reporting person is one of the Principals of Relational Investors LLC ("RILLC"). RILLC is the record owner of 100 shares and sole general partner, or the sole managing member of the general partner, of Relational Investors, L.P., Relational Fund Partners, L.P., Relational Coast Partners, L.P., RH Fund 1, L.P., RH Fund 6, L.P., Relational Investors VIII, L.P., Relational Investors IX, L.P., Relational Investors X, L.P., Relational Investors XV, L.P., Relational Investors XVI, L.P., Relational Investors XX, L.P., Relational Investors XXII, L.P., Relational Investors XXIII, L.P., and Relational Investors Alpha Fund I, L.P. The Limited Partnerships in footnote 1 own a total of 7,963,166 shares. An additional 2,234,482 shares are held in accounts managed by RILLC and an additional 408,500 shares are held through co-investment arrangements with certain entities listed in footnote 1. The reporting person disclaims beneficial ownership of these securities except to the extent of his pecuniary interest therein. The vested restricted stock units were scheduled to vest on the date of the 2011 annual meeting of shareholders. This option, which provided for vesting at the next annual meeting of shareholders, was cancelled upon the consummation of the sanofi-aventis tender offer in exchange for a payment representing (A) an amount of cash equal to the excess of $74.00 over the exercise price of the option, multiplied by the total number of shares subject to such options, and (B) one contingent value right (CVR) per cancelled option. Susan P. Cogswell, Attorney-in-Fact 2011-04-06