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                                                                  Exhibit 10.32


Page 1



November 15, 1999



Mr. Wayne P. Yetter
Chief Operating Officer
IMS Health
660 West Germantown Pike
Plymouth Meeting, PA 19462

Dear Wayne:

We are pleased to offer you a position on Transkaryotic Therapies, Inc.
("TKT" or the "Company") Board of Directors effective as of November 15,
1999, upon the following terms and conditions:

1.     TERM.  Unless you earlier resign or are removed, you will serve until
       the next annual meeting of the Company's stockholders and until your
       successor is duly elected and qualified.

2.     DIRECTORS' FEES.  As compensation for your services, you will receive
       a Director's fee of $1,000 for attendance at each meeting of the Board
       including Annual Meeting, other than telephonic meetings. The Company
       will also reimburse you for reasonable out-of-pocket expenses incurred
       by you in the performance of your duties as a Director of the Company
       upon presentation to the Company of an itemized and appropriately
       documented invoice for such expenses.

3.     STOCK.  Upon your election to the Board of Directors at the next
       annual meeting, the Company will grant you an option to purchase 6,750
       shares of Common Stock at an exercise price per share equal to the
       fair market value on that date. The options will be granted under the
       terms and conditions of the 1993 Directors' Plan. Thereafter, at each
       subsequent annual meeting, contingent upon your continued election,
       you will receive an annual option grant under the 1993 Directors' Plan
       to purchase 6,750 shares of Common Stock at an exercise price per
       share equal to the fair market value on that date.

4.     CONFIDENTIALITY.

            (a)  You recognize and acknowledge that the Company's trade
                 secrets,
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                 know-how and proprietary processes as they may exist from
                 time to time (including, without limitation, information
                 regarding methods, cultures, vectors, plasmids, synthesis
                 techniques, nucleic acid sequences, purification techniques
                 and assay procedures) as well as the Company's confidential
                 business plans and financial data are valuable, special and
                 unique assets of the Company's business, access to and
                 knowledge of which are essential to the performance of your
                 duties as a Director of the Company. You agree that you will
                 not, while you are serving as a Director of the Company or
                 thereafter, in whole or in part, disclose such secrets,
                 know-how, processes, business plans or financial data to any
                 person, firm, corporation, association or other entity for
                 any reason or purpose whatsoever, nor shall you make use of
                 any such property for your own purposes or for the benefit
                 of any person, firm, corporation or other entity (except the
                 Company) under any circumstances while you are serving as a
                 Director of the Company or thereafter, provided that these
                 restrictions shall not apply to such secrets, know-how and
                 processes which you can establish by competent proof:

                      (i)     were known to you, as evidenced by written
                              documents, other than under binder of secrecy,
                              prior to your serving as a Director of the
                              Company;

                     (ii)     have passed into the public domain prior to or
                              after their development by or for the Company,
                              other than through acts or omissions
                              attributable to you; or

                    (iii)     were subsequently obtained by you, other than
                              under binder of secrecy, from a third party not
                              acquiring the information under an obligation
                              of confidentiality from the disclosing party.

            (b)  Upon your resignation, removal or completion of your term as
                 a Director of the Company, you shall promptly turn over to
                 the Company all originals and copies of the Company's
                 confidential information described in this Section 4 then in
                 your possession or under your control.

5.     COVENANTS NOT TO COMPETE.

            (a)  While you serve as a Director of the Company, you shall not
                 engage in any business (whether as an officer, director,
                 owner, employee, partner, consultant, advisor or other
                 direct or indirect participant)
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                 engaged in the development of gene activation methods,
                 and/or the sale of products or rendering of services related
                 to gene activation, and/or to any other activities which
                 directly compete with the Company's business activities. It
                 is understood that this clause does not apply to your
                 current position at IMS Health.

            (b)  During the period in which this covenant not to compete is
                 in effect you also shall not interfere with, disrupt or
                 attempt to disrupt the relationship, contractual or
                 otherwise, between the Company and any customer, supplier,
                 lessor, lessee, employee, consultant, research partner or
                 investor of the Company.

            (c)  It is the desire and intent of the parties that the
                 provisions of this Section 5 shall be enforced to the
                 fullest extent permissible under the laws and public
                 policies applied in each jurisdiction in which enforcement
                 is sought. Accordingly, if any particular subsection or
                 portion of this Section 5 shall be deemed amended to delete
                 therefrom the portion thus adjudicated to be invalid or
                 unenforceable, such deletion shall apply only with respect
                 to the operation of this Section in the particular
                 jurisdiction in which such adjudication is made.

If you agree to accept this offer, please so indicate by countersigning the
enclosed duplicate of this letter and returning it to me.

                                   Very truly yours,

                                   TRANSKARYOTIC THERAPIES, INC.




                                   By: /s/ Richard F Selden
                                       ------------------------------------
                                       Richard F Selden
                                       President & Chief Executive Officer

Accepted and agreed to:


/s/ Wayne P. Yetter
-----------------------------
Wayne P. Yetter


November 24, 1999
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Date