<PAGE>

                                                                      EXHIBIT 99

                         GENZYME TRANSGENICS CORPORATION

             Important Factors Regarding Forward-Looking Statements

                                   March 2001


      In this Exhibit 99, "we," "us," "our" and "GTC" refer to Genzyme
Transgenics Corporation and its subsidiaries.

      From time to time, we may make forward-looking public statements, such as
statements concerning our then expected future revenues or earnings or
concerning projected plans, performance, contract procurement as well as other
estimates relating to future operations. Forward-looking statements may be in
reports filed under the Securities Exchange Act of 1934, as amended (the
"Exchange Act"), in press releases or informal statements made with the approval
of an authorized executive officer. The words or phrases "will likely result,"
"are expected to," "will continue," "is anticipated," "estimate," "project," or
similar expressions are intended to identify "forward-looking statements" within
the meaning of Section 21E of the Exchange Act and Section 27A of the Securities
Act of 1933, as amended, as enacted by the Private Securities Litigation Reform
Act of 1995.

      We wish to caution you not to place undue reliance on these
forward-looking statements which speak only as of the date on which they are
made. In addition, we wish to advise you that the factors listed below, as well
as other factors we have not currently identified, could affect our financial or
other performance and could cause our actual results for future periods to
differ materially from any opinions or statements expressed with respect to
future periods or events in any current statement.

      We will not undertake and specifically decline any obligation to publicly
release revisions to these forward-looking statements to reflect either
circumstances after the date of the statements or the occurrence of events which
may cause us to re-evaluate our forward-looking statements.

      In connection with the "safe harbor" provisions of the Private Securities
Litigation Reform Act, we are hereby filing cautionary statements identifying
important factors that could cause our actual results to differ materially from
those projected in forward-looking statements made by us or on our behalf.

We expect to incur future operating losses and may never become profitable.

      We have had operating losses since our inception, and we expect losses to
continue for the next several years. From our inception in 1993 to December 31,
2000, we have incurred cumulative losses of approximately $79.8 million. These
losses have resulted principally from the costs of our research activities and
expenses in excess of revenues. We expect to continue incurring significant
operating losses until product sales sufficiently fund our operations. We cannot
be certain that we will become profitable.

We face uncertainty in raising additional funds necessary to fund our
operations.

      In order to develop and bring our transgenic products to market, we and
our partners must commit substantial resources to costly and time consuming
research, preclinical testing and clinical trials. If our businesses do not
become profitable before we exhaust existing resources, we will need to obtain
additional financing, through public or private sources, including debt or
equity financings, or through collaborative or other arrangements with corporate
partners. We may not be able to obtain adequate funds for our operations from
these sources when needed or on acceptable terms. If we raise additional capital
through the sale of equity, or securities convertible into equity, your
proportionate ownership in GTC may be diluted. If we cannot obtain additional
financing, we could be forced to delay, scale back or eliminate some of our
research and development programs.

      These forward-looking statements regarding our expected need for
additional funds are subject to risks and uncertainties. Our cash requirements
may vary materially from those now planned, depending upon the results of
existing businesses, the terms of future collaborations, results of research and
development, competitive and technological advances, regulatory requirements and
other factors.


                                       1
<PAGE>

Transgenic technology is in a relatively early stage.

      Developing products based on transgenic technology is subject to
significant technological risks. Most of our transgenic proteins are in the
early development stage and will require time consuming and costly development,
testing and regulatory clearance. We have not, nor to our knowledge, has any
other entity completed human clinical trials necessary to receive marketing
authorization for any protein produced in the milk of transgenic animals. We
cannot be certain that we will be able to do so successfully, nor can we assure
that any transgenically produced protein will be safe or effective. In addition,
it is possible that research and discoveries by others will render our
transgenic technology obsolete or noncompetitive.

We cannot market and sell our transgenic products in the United States or in
other countries if we fail to obtain the necessary regulatory approvals.

      Obtaining required regulatory approvals for our transgenically produced
products may take several years to complete and may consume substantial capital
resources. We cannot give any assurance that the FDA or any other regulatory
authority will act quickly or favorably on our requests for approval, or that
the FDA or any other regulatory authority will not require us to provide
additional data that we do not currently anticipate in order to obtain
approvals. We cannot apply for FDA approval to market any of our products under
development until the product successfully completes its preclinical and
clinical trials. Several factors could prevent successful completion or cause
significant delays of these trials, including an inability to enroll the
required number of patients or failure to demonstrate adequately that the
product is safe and effective for use in humans. If safety concerns develop, the
FDA could stop our trials before completion. Moreover, to our knowledge, no
protein produced in the milk of a transgenic animal has reached the stage in the
regulatory process which would allow it to be submitted to the FDA for final
regulatory approval. Because transgenic products represent novel therapeutic
products, the process for regulatory approval is unproven. There may be
additional delays in regulatory approval due to issues arising from the breeding
of transgenic animals and the use of proteins derived from such animals. If we
are not able to obtain regulatory approvals for use of our products under
development, or if the patient populations for which they are approved are not
sufficiently broad, the commercial success of our products could be limited.

We cannot assure the commercial success of transgenic products.

      Even if our transgenically produced products are successfully developed
and approved by the FDA and corresponding foreign regulatory agencies, they may
not enjoy commercial acceptance or success, which would adversely affect our
business and results of operations. Several factors could limit our success,
including:

   o  possible limited market acceptance among patients, physicians, medical
      centers and third party payors;

   o  our inability to access a sales force capable of marketing the product;

   o  our inability to supply a sufficient amount of product to meet market
      demand;

   o  the number and relative efficacy of competitive products that may
      subsequently enter the market; and

   o  for a transgenic product designed to replace or supplement currently
      marketed non-transgenic products, the relative risk-benefit profile and
      cost-effectiveness of the transgenically produced product.

      In addition, it is possible that we or our collaborative partners will be
unsuccessful in developing, marketing and implementing a commercialization
strategy for any transgenic products.

If we obtain regulatory approval of our transgenic products, the products will
be subject to continuing review and extensive regulatory requirements which
could affect their manufacture and marketing.

      The FDA and foreign regulatory agencies continue to review products even
after they have received initial approval. If and when the FDA or other agency
approves any of our transgenic products under development, the manufacture and
marketing of these products will be subject to continuing regulation, including
compliance with current Quality Systems Regulations and Good Manufacturing
Practices, known as QSR/GMP, adverse event reporting requirements and
prohibitions on promoting a product for unapproved uses. We will also be
required to obtain additional approvals in the event we significantly alter the
product's labeling or manufacturing process. Enforcement actions resulting from
failure to comply with QSR/GMP requirements could result in fines, suspensions
of approvals, recalls of


                                       2
<PAGE>

products, operating restrictions and criminal prosecutions, and affect the
manufacture and marketing of our transgenic products. The FDA or other
regulatory agencies could withdraw a previously approved product from the market
upon receipt of newly discovered information, including a failure to comply with
regulatory requirements, the occurrence of unanticipated problems with products
following approval, or for other reasons. Any of these withdrawals could
adversely affect our operating results.

We depend on collaboration agreements for our revenue.

      Our revenue stream and our business strategy depend largely on our
entering into transgenic development agreements with third parties. We may not
be able to establish these agreements, and we cannot guarantee that we will
establish our agreements on commercially acceptable terms. Our future agreements
may not ultimately be successful. Even if we enter into transgenic development
agreements, our partners could terminate these agreements or they could expire
before meaningful developmental milestones are reached. The termination or
expiration of any of these agreements could have a material adverse effect on
our business.

      Much of the revenue that we may receive under these collaborations will
depend upon our partners' ability to successfully develop and commercially
introduce, market and sell new products derived from our transgenic production
systems. Our partners may develop competitive production technologies or
competitive products outside of their collaborations with us that could have a
material adverse effect on our business.

      To date, the scope of our collaboration agreements have generally been
limited to transgenically producing limited quantities of targeted proteins. We
cannot be certain that these initial development projects will be successful or
lead to collaboration agreements to commercially produce any proteins. Depending
upon the terms of any future collaborations, our role in the collaboration will
often be limited to the production aspects of the proteins. As a result, we may
also be dependent on collaborators for other aspects of the development,
preclinical and clinical testing, regulatory approval, sales, marketing and
distribution of any transgenic product.

Genzyme has guaranteed our credit line.

      As of December 31, 2000, we had a $15.8 million credit line, none of which
is outstanding, and which is guaranteed by Genzyme through December 28, 2001.
When Genzyme's guaranty expires, we might not be able to negotiate an extension
or replacement of the credit facility on acceptable terms.

Future funding for ATIII is uncertain.

      We have been developing ATIII in a joint venture in which Genzyme
Corporation provides substantial funding. In November 2000, we executed a
non-binding letter of intent with Genzyme which contemplates our purchase of
Genzyme's interest in this joint venture. We have not completed the transaction
at this time and can not be assured that it will be completed. In February 2001,
the ATIII LLC announced that it had terminated development of ATIII for the
Heparin Resistance indication. We are in the process of evaluating possible
alternative indications for ATIII which may require substantial additional
funding if pursued either on our own or in conjunction with Genzyme. While we
expect to be able to fund ATIII on our own or obtain funding from another
partner on acceptable terms, it is possible that regulatory events or other
product development events will cause our expectations to be incorrect.

Concentration of ownership of our stock could lead to failure to maximize stock
price and conflicts of interest.

      Genzyme is our largest single stockholder. As of December 28, 2000 Genzyme
beneficially owned 8,263,243 shares of our outstanding common stock, assuming
the exercise by Genzyme of currently exercisable warrants to purchase our common
stock. Genzyme's ownership interest gives it significant influence over matters
requiring our stockholders' approval, including electing directors, adopting or
amending provisions of our articles of organization or by-laws and approving or
preventing some mergers or other similar transactions, such as a sale of
substantially all of our assets, or transactions that could give our
stockholders the opportunity to realize a premium over the then-prevailing price
for their shares. Our stockholders, other than Genzyme, will be minority equity
holders and, acting alone, will be unable to significantly influence our
management or business policies. Three of the seven members of our board of
directors also serve as directors and/or executive officers of Genzyme. The
interests of Genzyme and GTC may differ from time to time.


                                       3
<PAGE>

Our business may fail due to intense competition in our industry.

      The industries in which we operate are highly competitive and may become
even more competitive. We will need to continue to devote substantial efforts
and expense to research and development in order to maintain a competitive
position. It is possible that developments by others will render our current and
proposed services, products or technologies obsolete. In addition, we may
encounter significant competition for protein development and production
contracts from other companies. Transgenic products may face significant
competition from biological products manufactured in cell culture or by other
traditional protein production methods. Our businesses will compete against
other companies whose business is dedicated to offering transgenic production
and with prospective customers or collaborators who decide to pursue such
transgenic production internally. Many of these competitors have greater
financial and human resources and more experience in research and development
than we have. Competitors that complete clinical trials, obtain regulatory
approvals and begin commercial sales of their products before us will enjoy a
significant competitive advantage. We anticipate that we will face increased
competition in the future as new companies enter the market and alternative
technologies become available.

The public may have concerns about genetic engineering in animals and animal
testing.

      Many of our activities involve genetic engineering in animals and animal
testing. These types of activities have been the subject of controversy and
adverse publicity. Animal rights groups and various other organizations and
individuals have attempted to stop genetic engineering activities and animal
testing by pressing for legislation and regulation in these areas. To the extent
the activities of such groups are successful, they may adversely affect our
business.

The successful commercialization of our products will depend on obtaining
coverage and reimbursement for use of these products from third-party payors.

      Sales of pharmaceutical products largely depend on the reimbursement of
patients' medical expenses by government health care programs and private health
insurers. Without the financial support of the government or third party
insurers, the market for transgenic products will be limited. We cannot be sure
that third party payors will reimburse sales of our transgenic products, or
enable us or our partners to sell them at profitable prices.

      The federal government and private insurers have considered ways to
change, and have changed, the manner in which health care services are provided
and paid for in the United States. In particular, these third party payors are
increasingly attempting to contain health care costs by limiting both coverage
and the level of reimbursement for new therapeutic products. In the future, it
is possible that the government may institute price controls and further limits
on Medicare and Medicaid spending. These controls and limits could affect the
payments we collect from sales of our products. Internationally, medical
reimbursement systems vary significantly, with some medical centers having fixed
budgets, regardless of levels of patient treatment, and other countries
requiring application for, and approval of, government or third party
reimbursement. Even if we or our partners succeed in bringing transgenic
products to market, uncertainties regarding future health care policy,
legislation and regulation, as well as private market practices, could affect
our ability to sell our products in commercially acceptable quantities at
profitable prices.

Our business exposes us to potential service and product liability.

      The nature of our business exposes us to potential product and
professional liability risks which are inherent in the testing, production,
marketing and sale of human therapeutic products. While we have obtained product
and professional liability insurance under an insurance policy arrangement with
Genzyme and Genzyme's affiliates, we cannot be certain that our insurance
coverage will be sufficient to cover any claim. Uninsured product or service
liability could have a material adverse effect on our financial results.
Additionally, it is possible that any insurance will not provide us with
adequate protection against potential liabilities. Potential liability may arise
from our handling of clinical samples containing human blood and tissues, which
may contain human pathogens. It is also possible that liability may arise from
handling animal blood and tissue which may contain zoonotic pathogens. Although
such products are used only in the laboratory, inadvertent human contact may
occur.

Qualified managerial and scientific personnel are scarce in our industry.

      We are highly dependent on the principal members of our scientific and
management staff. Our success will depend in part on our ability to identify,
attract and retain qualified managerial and scientific personnel. There is
intense competition for qualified personnel in our industry. We may not be able
to continue to attract and retain personnel with the advanced technical
qualifications or managerial expertise necessary for the development of our
business. If we fail to


                                       4
<PAGE>

attract and retain key personnel, it could have a material adverse effect on our
business, financial condition and results of operations.

We depend on patents and proprietary rights that may fail to protect our
business.

      Our success will partly depend on our ability to obtain and maintain
patent or other proprietary protection for our technologies, products and
processes such as:

   -  compositions of matter or processes;

   -  processes developed by our employees; or

   -  uses of compositions of matter discovered through our technology.

      We may not be able to obtain the necessary protection. Our success will
also depend on our ability to operate without infringing the proprietary rights
of other parties. Legal standards relating to the validity of patents covering
pharmaceutical and biotechnological inventions and the scope of claims made
under these patents are still developing. There is no consistent policy
regarding the breadth of claims allowed in biotechnology patents. The patent
position of a biotechnology firm is highly uncertain and involves complex legal
and factual questions.

      We have been issued six patents and currently have 20 provisional or
regular applications solely owned by us and two regular applications co-owned
with others pending in the United States. Where appropriate there are
counterparts in other countries. We may not receive any issued patents based on
pending or future applications. Our issued patents may not contain claims
sufficiently broad to protect us against competitors with similar technology.
Additionally, our patents, our partners' patents and patents for which we have
license rights may be challenged, narrowed, invalidated or circumvented.
Furthermore, rights granted under patents may not provide us with any
competitive advantage.

      We may have to initiate arbitration or litigation to enforce our patent
and license rights. If our competitors file patent applications that claim
technology also claimed by us, we may have to participate in interference or
opposition proceedings to determine the priority of invention. An adverse
outcome could subject us to significant liabilities to third parties and require
us to cease using the technology or to license the disputed rights from third
parties. We may not be able to obtain any required licenses on commercially
acceptable terms or at all.

      The cost to us of any litigation or proceeding relating to patent rights,
even if resolved in our favor, could be substantial. Some of our competitors may
be able to sustain the costs of complex patent litigation more effectively than
we can because of their substantially greater resources. Uncertainties resulting
from the initiation and continuation of any pending patent or related litigation
could have a material adverse effect on our ability to compete in the
marketplace.

      We rely on certain proprietary trade secrets and know-how that are not
patentable. We have taken measures to protect our unpatented trade secrets and
know-how, including having our employees, consultants and some contractors
execute confidentiality agreements. These agreements could be breached. If so,
it is possible that our remedies for a given breach might be inadequate. It is
also possible that competitors could independently develop or discover our trade
secrets or that the trade secrets could otherwise become known.

We have obligations to issue shares of common stock in the future which will
dilute your ownership interest and may adversely affect our stock price.

      Sales of substantial amounts of our common stock in the public market, or
the perception that such sales may occur could adversely affect the prevailing
market price of our common stock. As of December 31, 2000, there were 29,697,151
shares of our common stock outstanding. As of December 31, 2000, options to
purchase an aggregate of 2,454,905 shares of common stock at varying exercise
prices were outstanding; of this total, options to purchase 1,354,984 shares
were immediately exercisable and these shares could be immediately resold into
the public market. As of November 27, 2000, Genzyme held 7,844,919 shares of our
common stock which could be sold into the public markets under Rule 144 of the
Securities Act. Genzyme is also entitled to registration rights with respect to
some of these shares. An additional 518,324 shares are issuable to Genzyme upon
exercise of outstanding warrants are also entitled to registration rights, which
could expedite the resale of such shares into the public market.


                                       5
<PAGE>

Our common stock may have a volatile public trading price and low trading
volume.

      The market price of our common stock has been highly volatile and the
market for our common stock has experienced significant price and volume
fluctuations, some of which are unrelated to our Company's operating
performance. Many factors can have a significant adverse effect on our common
stock's market price, including:

   o  announcements by us or our competitors of technological innovations or new
      commercial products;

   o  developments concerning our proprietary rights, including patent and
      litigation matters;

   o  publicity regarding actual or potential results relating to our or our
      partners' products or compounds under development;

   o  an unexpected termination of one of our partnerships;

   o  regulatory developments in the United States and other countries;

   o  general market conditions; and

   o  quarterly fluctuations in our revenues and other financial results.

Anti-takeover provisions in our charter and by-laws and Massachusetts law may
adversely affect our stock price.

      Our articles of organization, certain provisions of our by-laws and
certain provisions of Massachusetts law could delay or make more difficult a
merger, tender offer or proxy contest involving us. These provisions may have
the effect of delaying or preventing a change of control without action by the
stockholders and, therefore, could adversely affect the price of our common
stock.


                                       6