SEC FORM 4

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person^*

BERTHIAUME DOUGLAS A

(Last)

(First)

(Middle)

500 KENDALL STREET

(Street)

CAMBRIDGE

02142

(City)

(State)

(Zip)

2. Issuer Name and Ticker or Trading Symbol
GENZYME CORP [ GENZ ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director	10% Owner
	Officer (give title below)	Other (specify below)

3. Date of Earliest Transaction (Month/Day/Year)
04/04/2011

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	Code	V	Amount	(A) or (D)	Price		6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
Genzyme common stock (GENZ)	04/04/2011		M		2,375	A	$0.0000	73,533	D
Genzyme common stock (GENZ)	04/04/2011		M		949.906	A	$0⁽¹⁾	74,482.906	D
Genzyme common stock (GENZ)	04/04/2011		M		609.952	A	$0⁽¹⁾	75,092.858	D
Genzyme common stock (GENZ)	04/04/2011		M		511.474	A	$0⁽¹⁾	75,604.332	D
Genzyme common stock (GENZ)	04/04/2011		M		445.149	A	$0⁽¹⁾	76,049.481	D
Genzyme common stock (GENZ)	04/04/2011		M		430.322	A	$0⁽¹⁾	76,479.803	D
Genzyme common stock (GENZ)	04/04/2011		M		419.937	A	$0⁽¹⁾	76,899.74	D
Genzyme common stock (GENZ)	04/04/2011		M		406.711	A	$0⁽¹⁾	77,306.451	D
Genzyme common stock (GENZ)	04/04/2011		M		405.71	A	$0⁽¹⁾	77,712.161	D
Genzyme common stock (GENZ)	04/04/2011		M		391.993	A	$0⁽¹⁾	78,104.154	D
Genzyme common stock (GENZ)	04/04/2011		M		368.937	A	$0⁽¹⁾	78,473.091	D
Genzyme common stock (GENZ)	04/04/2011		M		322.9	A	$0⁽¹⁾	78,795.991	D
Genzyme common stock (GENZ)	04/04/2011		M		318.328	A	$0⁽¹⁾	79,114.319	D
Genzyme common stock (GENZ)	04/04/2011		M		314.696	A	$0⁽¹⁾	79,429.015	D
Genzyme common stock (GENZ)	04/04/2011		M		292.752	A	$0⁽¹⁾	79,721.767	D
Genzyme common stock (GENZ)	04/04/2011		M		286.498	A	$0⁽¹⁾	80,008.265	D
Genzyme common stock (GENZ)	04/04/2011		M		274.709	A	$0⁽¹⁾	80,282.974	D
Genzyme common stock (GENZ)	04/04/2011		M		266.952	A	$0⁽¹⁾	80,549.926	D
Genzyme common stock (GENZ)	04/04/2011		M		262.392	A	$0⁽¹⁾	80,812.318	D
Genzyme common stock (GENZ)	04/04/2011		M		254.772	A	$0⁽¹⁾	81,067.09	D
Genzyme common stock (GENZ)	04/04/2011		M		233.401	A	$0⁽¹⁾	81,300.491	D
Genzyme common stock (GENZ)	04/04/2011		M		230.137	A	$0⁽¹⁾	81,530.628	D
Genzyme common stock (GENZ)	04/04/2011		M		224.025	A	$0⁽¹⁾	81,754.653	D
Genzyme common stock (GENZ)	04/04/2011		M		211.121	A	$0⁽¹⁾	81,965.774	D
Genzyme common stock (GENZ)	04/04/2011		M		208.531	A	$0⁽¹⁾	82,174.305	D
Genzyme common stock (GENZ)	04/04/2011		M		188.58	A	$0⁽¹⁾	82,362.885	D
Genzyme common stock (GENZ)	04/04/2011		M		175.975	A	$0⁽¹⁾	82,538.86	D
Genzyme common stock (GENZ)	04/04/2011		D		2,375	D	$74	80,163.86	D
Genzyme common stock (GENZ)	04/04/2011		D		9,005.86	D	$76.01	71,158	D
Genzyme common stock (GENZ)	04/04/2011		U		71,158	D	$74	0.0000	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares	8. Price of Derivative Security (Instr. 5)		10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
Phantom Stock	⁽¹⁾	04/04/2011		M			254.772	03/31/2005⁽¹⁾	12/31/2034	Genzyme common stock (GENZ)	254.772	$0.0000	0.0000	D
Phantom Stock	⁽¹⁾	04/04/2011		M			211.121	03/31/2006⁽¹⁾	12/31/2034	Genzyme common stock (GENZ)	211.121	$0.0000	0.0000	D
Phantom Stock	⁽¹⁾	04/04/2011		M			286.498	03/31/2007⁽¹⁾	12/31/2034	Genzyme common stock (GENZ)	286.498	$0.0000	0.0000	D
Phantom Stock	⁽¹⁾	04/04/2011		M			314.696	03/31/2008⁽¹⁾	12/31/2034	Genzyme common stock (GENZ)	314.696	$0.0000	0.0000	D
Phantom Stock	⁽¹⁾	04/04/2011		M			405.71	03/31/2009⁽¹⁾	12/31/2034	Genzyme common stock (GENZ)	405.71	$0.0000	0.0000	D
Phantom Stock	⁽¹⁾	04/04/2011		M			511.474	03/31/2010⁽¹⁾	⁽¹⁾	Genzyme common stock (GENZ)	511.474	$0.0000	0.0000	D
Phantom Stock	⁽¹⁾	04/04/2011		M			274.709	06/30/2004⁽¹⁾	12/20/2034	Genzyme common stock (GENZ)	274.709	$0.0000	0.0000	D
Phantom Stock	⁽¹⁾	04/04/2011		M			208.531	06/30/2005⁽¹⁾	12/31/2034	Genzyme common stock (GENZ)	208.531	$0.0000	0.0000	D
Phantom Stock	⁽¹⁾	04/04/2011		M			266.952	06/30/2006⁽¹⁾	12/31/2034	Genzyme common stock (GENZ)	266.952	$0.0000	0.0000	D
Phantom Stock	⁽¹⁾	04/04/2011		M			230.137	06/30/2007⁽¹⁾	12/31/2034	Genzyme common stock (GENZ)	230.137	$0.0000	0.0000	D
Phantom Stock	⁽¹⁾	04/04/2011		M			368.937	06/30/2008⁽¹⁾	12/31/2034	Genzyme common stock (GENZ)	368.937	$0.0000	0.0000	D
Phantom Stock	⁽¹⁾	04/04/2011		M			430.322	06/30/2009⁽¹⁾	⁽¹⁾	Genzyme common stock (GENZ)	430.322	$0.0000	0.0000	D
Phantom Stock	⁽¹⁾	04/04/2011		M			949.906	06/30/2010⁽¹⁾	⁽¹⁾	Genzyme common stock (GENZ)	949.906	$0.0000	0.0000	D
Phantom Stock	⁽¹⁾	04/04/2011		M			188.58	09/30/2004⁽¹⁾	12/31/2034	Genzyme common stock (GENZ)	188.58	$0.0000	0.0000	D
Phantom Stock	⁽¹⁾	04/04/2011		M			175.975	09/30/2005⁽¹⁾	12/31/2034	Genzyme common stock (GENZ)	175.975	$0.0000	0.0000	D
Phantom Stock	⁽¹⁾	04/04/2011		M			224.025	09/30/2006⁽¹⁾	12/31/2034	Genzyme common stock (GENZ)	224.025	$0.0000	0.0000	D
Phantom Stock	⁽¹⁾	04/04/2011		M			318.328	09/30/2007⁽¹⁾	12/31/2034	Genzyme common stock (GENZ)	318.328	$0.0000	0.0000	D
Phantom Stock	⁽¹⁾	04/04/2011		M			262.392	09/30/2008⁽¹⁾	12/31/2034	Genzyme common stock (GENZ)	262.392	$0.0000	0.0000	D
Phantom Stock	⁽¹⁾	04/04/2011		M			406.711	09/30/2009⁽¹⁾	⁽¹⁾	Genzyme common stock (GENZ)	406.711	$0.0000	0.0000	D
Phantom Stock	⁽¹⁾	04/04/2011		M			233.401	12/31/2004⁽¹⁾	12/31/2034	Genzyme common stock (GENZ)	233.401	$0.0000	0.0000	D
Phantom Stock	⁽¹⁾	04/04/2011		M			292.752	12/31/2005⁽¹⁾	12/31/2034	Genzyme common stock (GENZ)	292.752	$0.0000	0.0000	D
Phantom Stock	⁽¹⁾	04/04/2011		M			445.149	12/31/2006⁽¹⁾	12/31/2034	Genzyme common stock (GENZ)	445.149	$0.0000	0.0000	D
Phantom Stock	⁽¹⁾	04/04/2011		M			391.993	12/31/2007⁽¹⁾	12/31/2034	Genzyme common stock (GENZ)	391.993	$0.0000	0.0000	D
Phantom Stock	⁽¹⁾	04/04/2011		M			419.937	12/31/2008⁽¹⁾	12/31/2034	Genzyme common stock (GENZ)	419.937	$0.0000	0.0000	D
Phantom Stock	⁽¹⁾	04/04/2011		M			609.952	12/31/2009⁽¹⁾	⁽¹⁾	Genzyme common stock (GENZ)	609.952	$0.0000	0.0000	D
Phantom Stock	⁽¹⁾	04/04/2011		M			322.9	12/31/2010⁽¹⁾	⁽¹⁾	Genzyme common stock (GENZ)	322.9	$0.0000	0.0000	D
Restricted Stock Units	$0.0000	04/04/2011		M			2,375	⁽²⁾	⁽²⁾	Genzyme common stock (GENZ)	2,375	$0.0000	0.0000	D
Stock Option (right to buy)	$51.52	04/04/2011		D			7,125	⁽³⁾	06/16/2020	Genzyme common stock (GENZ)	7,125	$51.52	0.0000	D
Stock Option (right to buy)	$43.9	04/04/2011		D			15,000	05/27/2005⁽³⁾	05/27/2014	Genzyme common stock (GENZ)	15,000	$43.9	0.0000	D
Stock Option (right to buy)	$53.47	04/04/2011		D			18,000	05/31/2002⁽³⁾	05/31/2011	Genzyme common stock (GENZ)	18,000	$53.47	0.0000	D

Explanation of Responses:

1. 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 Apiril 1, 2004 through December 31, 2010, pursuant to the Reporting Person?s plan election and the terms of the plan.

2. The vested restricted stock units were scheduled to vest on the date of the 2011 annual meeting of shareholders.

3. 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.

Remarks:

,Multiple Forms Submitted

	Susan P. Cogswell, Attorney-in-Fact	04/06/2011
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.