Exhibit 10.1

EXECUTION COPY

$350,000,000

CREDIT AGREEMENT

among

GENZYME CORPORATION,

as Parent Borrower,

THE SUBSIDIARY BORROWERS,

The Several Lenders from Time to Time Parties Hereto,

BANK OF AMERICA, N.A.,

as Syndication Agent,

ABN AMRO BANK N.V.,

CITIZENS BANK OF MASSACHUSETTS,

and

WACHOVIA BANK, NATIONAL ASSOCIATION,

as Co-Documentation Agents

and

JPMORGAN CHASE BANK, N.A.,

as Administrative Agent

Dated as of July 14, 2006

J.P. MORGAN SECURITIES INC.

BANK OF AMERICA SECURITIES LLC

as Co-Lead Arrangers and Joint Bookrunners

4.1	Financial Condition	34
4.2	No Change	34
4.3	Existence; Compliance with Law	35
4.4	Power; Authorization; Enforceable Obligations	35
4.5	No Legal Bar	35
4.6	Litigation	35
4.7	No Default	35
4.8	Liens	35
4.9	Intellectual Property	35
4.10	Taxes	36
4.11	Federal Regulations	36
4.12	Labor Matters	36
4.13	ERISA	36
4.14	Investment Company Act; Other Regulations	36
4.15	Material Subsidiaries	37
4.16	Use of Proceeds	37
4.17	Accuracy of Information, etc	37

SECTION 5.	CONDITIONS PRECEDENT	37

5.1	Conditions to Initial Extension of Credit	37
5.2	Conditions to Each Extension of Credit	39

SECTION 6.	AFFIRMATIVE COVENANTS	39

6.1	Financial Statements	39
6.2	Certificates; Other Information	40
6.3	Payment of Obligations	40
6.4	Maintenance of Existence; Compliance	40
6.5	Maintenance of Property; Insurance	40
6.6	Inspection of Property; Books and Records; Discussions	40
6.7	Notices	41
6.8	Additional Subsidiary Guarantors	41
6.9	Guarantee Coverage Ratio	42

SECTION 7.	NEGATIVE COVENANTS	42

7.1	Financial Condition Covenants	42
7.2	Indebtedness	42
7.3	Liens	43
7.4	Fundamental Changes	44
7.5	Disposition of Property	44
7.6	Restricted Payments	45
7.7	Investments	45
7.8	Transactions with Affiliates	46
7.9	Sales and Leasebacks	46

		Page

SECTION 1.	DEFINITIONS	1

1.1	Defined Terms	1
1.2	Other Definitional Provisions	18

SECTION 2.	AMOUNT AND TERMS OF COMMITMENTS	18

2.1	Commitments	18
2.2	Procedure for Loan Borrowing	19
2.3	Swingline Commitment	19
2.4	Procedure for Swingline Borrowing; Refunding of Swingline Loans	20
2.5	Facility Fees, Utilization Fees, etc.	21
2.6	Termination or Reduction of Commitments	21
2.7	Additional Commitments	21
2.8	Optional Prepayments	22
2.9	Mandatory Prepayments and Commitment Reductions	22
2.10	Conversion and Continuation Options	22
2.11	Limitations on Eurocurrency Tranches	23
2.12	Interest Rates and Payment Dates	23
2.13	Computation of Interest and Fees	24
2.14	Inability to Determine Interest Rate	24
2.15	Pro Rata Treatment and Payments	25
2.16	Requirements of Law	26
2.17	Taxes	27
2.18	Indemnity	28
2.19	Change of Lending Office	29
2.20	Replacement of Lenders	29
2.21	Judgment Currency	30
2.22	Foreign Currency Exchange Rate	30
2.23	Subsidiary Borrowers	30

SECTION 3.	LETTERS OF CREDIT	31

3.1	L/C Commitment	31
3.2	Procedure for Issuance of Letter of Credit	32
3.3	Fees and Other Charges	32
3.4	L/C Participations	32
3.5	Reimbursement Obligation of the Borrowers	33
3.6	Obligations Absolute	33
3.7	Letter of Credit Payments	34
3.8	Applications	34

SECTION 4.	REPRESENTATIONS AND WARRANTIES	34

SECTION 8.	EVENTS OF DEFAULT	46

SECTION 9.	THE AGENTS	49

9.1	Appointment	49
9.2	Delegation of Duties	49
9.3	Exculpatory Provisions	49
9.4	Reliance by Administrative Agent	49
9.5	Notice of Default	50
9.6	Non-Reliance on Agents and Other Lenders	50
9.7	Indemnification	50
9.8	Agent in Its Individual Capacity	51
9.9	Successor Administrative Agent	51
9.10	Agents	51

SECTION 10.	MISCELLANEOUS	51

10.1	Amendments and Waivers	51
10.2	Notices	52
10.3	No Waiver; Cumulative Remedies	53
10.4	Survival of Representations and Warranties	53
10.5	Payment of Expenses and Taxes	53
10.6	Successors and Assigns; Participations and Assignments	54
10.7	Set-off