SCHEDULE 14A INFORMATION
Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934
                              (Amendment No.   )

Filed by the Registrant                        [X]
Filed by a Party other than the Registrant     [_]

Check the appropriate box:

[_]  Preliminary Proxy Statement
[_]  Confidential, for Use of the Commission Only (as permitted by Rule
      14a-6(e)(2))
[_]  Definitive Proxy Statement
[X]  Definitive Additional Materials
[_]  Soliciting Material under Rule 14a-12

                                Sequenom, Inc.
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               (Name of Registrant as Specified In Its Charter)


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    (Name of Person(s) Filing Proxy Statement if Other Than the Registrant)

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[X]  No fee required.
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1.   Title of each class of securities to which transaction applies:

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2.   Aggregate number of securities to which transaction applies:

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3.   Per unit price or other underlying value of transaction computed pursuant
     to Exchange Act Rule 0-11 (Set forth the amount on which the filing fee is
     calculated and state how it was determined):

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4.   Proposed maximum aggregate value of transaction:

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9.   Date Filed:

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                                Sequenom, Inc.
                            3595 John Hopkins Court
                          San Diego, California 92121
                                (858) 202-9000

                                August 24, 2001

Dear Fellow Stockholder:

   We are writing to update you on the Special Meeting of the Stockholders of
Sequenom, Inc. held on August 23, 2001. The meeting, which was to consider two
proposals described in the Proxy Statement recently mailed to you, was
adjourned until September 17, 2001 at 10:00 a.m., Pacific time. The first
proposal, the proposal to approve the transaction between Sequenom and Gemini
Genomics PLC, was approved at the meeting. The second proposal, the proposal
to amend Sequenom's Bylaws and Certificate of Incorporation, will be
considered at the reconvened meeting. Proxies that have already been voted
with respect to the second proposal will remain effective for use at the
September 17, 2001 reconvened meeting, unless changed or revoked. Stockholders
who are voting by proxy may revoke or change their vote with respect to the
second proposal until the meeting reconvenes. The reconvened meeting will be
held at Sequenom. All stockholders are of course welcome to attend the
reconvened meeting.

   I urge you to take this opportunity to vote your proxy with respect to the
second proposal today.

   For your convenience, we have enclosed a duplicate proxy card. Please take
the time to sign, date and return the proxy card in the envelope provided. You
may also vote your shares by telephone or the internet, as explained in the
enclosed instruction form. If you have any questions, please call Georgeson
Shareholder, who has been retained to assist us with the solicitation of
proxies at (800) 223-2064 or collect at (412) 391-3146. If you have any
questions for Sequenom, please call Abigail Devine, APR, Investor Relations,
at (858) 202-9032.

   As described in the Proxy Statement, the Sequenom board of directors has
unanimously recommended a vote "for" the proposal to amend Sequenom's Bylaws
and Certificate of Incorporation, in the belief that approval is in the best
interests of the stockholders.

   We appreciate your time and attention to this important matter.

                                          Sincerely,

                                          /s/ Stephen L. Zaniboni

                                          Stephen L. Zaniboni
                                          Senior Vice President, Chief
                                          Financial Officer and Secretary