X0303 4 2011-04-04 0000732485 GENZYME CORP GENZ 0001136998 MCGILLICUDY CORNELIUS III 500 KENDALL STREET CAMBRIDGE MA 02142 1 Genzyme common stock (GENZ) 2011-04-04 4 M 0 2375.0000 0.0000 A 7375.0000 D Genzyme common stock (GENZ) 2011-04-04 4 M 0 1833.3910 0 A 9208.3910 D Genzyme common stock (GENZ) 2011-04-04 4 M 0 327.2670 0 A 9535.6580 D Genzyme common stock (GENZ) 2011-04-04 4 M 0 316.3460 0 A 9852.0040 D Genzyme common stock (GENZ) 2011-04-04 4 M 0 292.9610 0 A 10144.9650 D Genzyme common stock (GENZ) 2011-04-04 4 M 0 278.6490 0 A 10423.6140 D Genzyme common stock (GENZ) 2011-04-04 4 M 0 258.3110 0 A 10681.9250 D Genzyme common stock (GENZ) 2011-04-04 4 M 0 254.0600 0 A 10935.9850 D Genzyme common stock (GENZ) 2011-04-04 4 M 0 253.8570 0 A 11189.8420 D Genzyme common stock (GENZ) 2011-04-04 4 M 0 252.2830 0 A 11442.1250 D Genzyme common stock (GENZ) 2011-04-04 4 M 0 237.4990 0 A 11679.6240 D Genzyme common stock (GENZ) 2011-04-04 4 M 0 233.4010 0 A 11913.0250 D Genzyme common stock (GENZ) 2011-04-04 4 M 0 230.7010 0 A 12143.7260 D Genzyme common stock (GENZ) 2011-04-04 4 M 0 227.2630 0 A 12370.9890 D Genzyme common stock (GENZ) 2011-04-04 4 M 0 201.2410 0 A 12572.2300 D Genzyme common stock (GENZ) 2011-04-04 4 M 0 192.1760 0 A 12764.4060 D Genzyme common stock (GENZ) 2011-04-04 4 M 0 191.1310 0 A 12955.5370 D Genzyme common stock (GENZ) 2011-04-04 4 M 0 163.2720 0 A 13118.8090 D Genzyme common stock (GENZ) 2011-04-04 4 M 0 161.6100 0 A 13280.4190 D Genzyme common stock (GENZ) 2011-04-04 4 D 0 2375.0000 74.0000 D 10905.4190 D Genzyme common stock (GENZ) 2011-04-04 4 U 0 5000.0000 74.0000 D 5905.4190 D Genzyme common stock (GENZ) 2011-04-04 4 D 0 5905.4190 76.0100 D 0.0000 D Phantom Stock 2011-04-04 4 M 0 327.2670 0.0000 D 2004-03-31 2026-12-31 Genzyme common stock (GENZ) 327.2670 0.0000 D Phantom Stock 2011-04-04 4 M 0 237.4990 0.0000 D 2005-03-31 2026-12-31 Genzyme common stock (GENZ) 237.4990 0.0000 D Phantom Stock 2011-04-04 4 M 0 254.0600 0.0000 D 2006-03-31 2026-12-31 Genzyme common stock (GENZ) 254.0600 0.0000 D Phantom Stock 2011-04-04 4 M 0 278.6490 0.0000 D 2007-03-31 2026-12-31 Genzyme common stock (GENZ) 278.6490 0.0000 D Phantom Stock 2011-04-04 4 M 0 230.7010 0.0000 D 2002-06-30 2026-12-31 Genzyme common stock (GENZ) 230.7010 0.0000 D Phantom Stock 2011-04-04 4 M 0 252.2830 0.0000 D 2004-06-30 2026-12-30 Genzyme common stock (GENZ) 252.2830 0.0000 D Phantom Stock 2011-04-04 4 M 0 192.1760 0.0000 D 2005-06-30 2026-12-31 Genzyme common stock (GENZ) 192.1760 0.0000 D Phantom Stock 2011-04-04 4 M 0 201.2410 0.0000 D 2006-06-30 2026-12-31 Genzyme common stock (GENZ) 201.2410 0.0000 D Phantom Stock 2011-04-04 4 M 0 191.1310 0.0000 D 2007-06-30 2026-12-31 Genzyme common stock (GENZ) 191.1310 0.0000 D Phantom Stock 2011-04-04 4 M 0 227.2630 0.0000 D 2004-09-30 2026-12-31 Genzyme common stock (GENZ) 227.2630 0.0000 D Phantom Stock 2011-04-04 4 M 0 161.6100 0.0000 D 2005-09-30 2026-12-31 Genzyme common stock (GENZ) 161.6100 0.0000 D Phantom Stock 2011-04-04 4 M 0 163.2720 0.0000 D 2006-09-30 2026-12-31 Genzyme common stock (GENZ) 163.2720 0.0000 D Phantom Stock 2011-04-04 4 M 0 253.8570 0.0000 D 2007-09-30 2026-12-31 Genzyme common stock (GENZ) 253.8570 0.0000 D Phantom Stock 2011-04-04 4 M 0 1833.3910 0.0000 D 2003-12-31 2026-12-31 Genzyme common stock (GENZ) 1833.3910 0.0000 D Phantom Stock 2011-04-04 4 M 0 233.4010 0.0000 D 2004-12-31 2026-12-31 Genzyme common stock (GENZ) 233.4010 0.0000 D Phantom Stock 2011-04-04 4 M 0 258.3110 0.0000 D 2005-12-31 2026-12-31 Genzyme common stock (GENZ) 258.3110 0.0000 D Phantom Stock 2011-04-04 4 M 0 292.9610 0.0000 D 2006-12-31 2026-12-31 Genzyme common stock (GENZ) 292.9610 0.0000 D Phantom Stock 2011-04-04 4 M 0 316.3460 0.0000 D 2007-12-31 2026-12-31 Genzyme common stock (GENZ) 316.3460 0.0000 D Restricted Stock Units 0.0000 2011-04-04 4 M 0 2375.0000 0.0000 D Genzyme common stock (GENZ) 2375.0000 0.0000 D Stock Option (right to buy) 46.2400 2011-04-04 4 D 0 9000.0000 46.2400 D 2013-05-29 Genzyme common stock (GENZ) 9000.0000 0.0000 D Stock Option (right to buy) 51.5200 2011-04-04 4 D 0 7125.0000 51.5200 D 2020-06-16 Genzyme common stock (GENZ) 7125.0000 0.0000 D Stock Option (right to buy) 58.6600 2011-04-04 4 D 0 7500.0000 58.6600 D 2010-05-21 2019-05-21 Genzyme common stock (GENZ) 7500.0000 0.0000 D Stock Option (right to buy) 68.4800 2011-04-04 4 D 0 7500.0000 68.4800 D 2009-05-22 2018-05-22 Genzyme common stock (GENZ) 7500.0000 0.0000 D Stock Option (right to buy) 62.1600 2011-04-04 4 D 0 15000.0000 62.1600 D 2008-05-24 2017-05-24 Genzyme common stock (GENZ) 15000.0000 0.0000 D Stock Option (right to buy) 58.5000 2011-04-04 4 D 0 15000.0000 58.5000 D 2007-05-25 2016-05-26 Genzyme common stock (GENZ) 15000.0000 0.0000 D Stock Option (right to buy) 62.9800 2011-04-04 4 D 0 24000.0000 62.9800 D 2006-05-26 2015-05-26 Genzyme common stock (GENZ) 24000.0000 0.0000 D Stock Option (right to buy) 53.4700 2011-04-04 4 D 0 4000.0000 53.4700 D 2002-05-31 2011-05-31 Genzyme common stock (GENZ) 4000.0000 0.0000 D The phantom stock acquired under the Genzyme Directors? Deferred Compensation Plan was cancelled at the completion of the sanofi-aventis tender offer and converted into the right to receive a cash payment based on the closing price of Genzyme common stock on the last day it traded. Phantom stock was credited to the Reporting Person?s stock account under the deferred compensation at the end of each fiscal quarter from 1/1/2004 through 12/31/2007, pursuant to the Reporting Person?s plan election and the terms of the plan. 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