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                                                                      EXHIBIT 99



             IMPORTANT FACTORS REGARDING FORWARD-LOOKING STATEMENTS

                                   April 1999



         From time to time, Genzyme Transgenics Corporation ("GTC" or the
"Company"), through its management, may make forward-looking public statements,
such as statements concerning then expected future revenues or earnings or
concerning projected plans, performance, product development and
commercialization 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 in oral
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.

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

         The Company will not undertake and specifically declines any obligation
to publicly release any revisions which may be made to any forward-looking
statements to reflect events or circumstances after the date of such statements
or to reflect the occurrence of anticipated or unanticipated events which may
cause management to re-evaluate such forward-looking statements.

         In connection with the "safe harbor" provisions of the Private
Securities Litigation Reform Act of 1995, the Company is hereby filing
cautionary statements identifying important factors that could cause the
Company's actual results to differ materially form those projected in
forward-looking statements of the Company made by or on behalf of the Company.

         HISTORY OF OPERATING LOSSES; NEED FOR ADDITIONAL FUNDS. GTC has had
operating losses since its inception and expects such losses to continue for the
next several years. For the period from its inception in 1993 to January 3,
1999, the Company incurred cumulative losses of approximately $48.4 million.
GTC's losses have resulted principally from costs incurred in connection with
research activities and from expenses in excess of revenues from the Company's
contract research organization ("CRO") services. GTC's sources of revenues to
date have consisted primarily of research and development contracts and CRO


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services. Such revenues to date have not been sufficient to generate profits.
The Company expects to continue to incur significant operating losses until such
time as product sales and CRO service revenues are sufficient to fund its
operations. No assurance can be given that the Company will become profitable.

         The Company currently believes that existing cash resources and
available financing will be sufficient to meet its operating cash flow needs and
capital requirements at least for the next year. The development of transgenic
products by the Company will require the commitment of substantial resources to
conduct costly and time-consuming research, preclinical testing and clinical
trials necessary to bring such products to market. If GTC's businesses do not
achieve profitable operations at or prior to the time such existing resources
are exhausted, the Company will need to obtain additional financing, through
public or private financings, including debt or equity financings, or through
collaborative or other arrangements with corporate partners, as appropriate.
Adequate funds for the Company's operations from such sources may not be
available when needed or on terms acceptable to the Company. If additional
financing cannot be obtained when needed or on acceptable terms, GTC could be
forced to delay, scale back or eliminate certain of its research and development
programs or to license to other parties rights to commercialize products or
technologies that the Company would otherwise seek to develop internally as well
as delaying or forgoing timely expansion, improvement or investment in the
Company's contract research services.

         The foregoing forward-looking statements regarding the Company's
expectations of the need for additional funds are subject to risks and
uncertainties. The Company's 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.

         EARLY STAGE OF TRANSGENIC TECHNOLOGY. Development of products based on
transgenic technology is subject to a number of significant technological risks
and the time period required for any such development is both lengthy and
uncertain. Neither GTC nor, to GTC's knowledge, any other entity has completed
human clinical trials of any protein produced in the milk of transgenic animals,
and there can be no assurance that GTC will be able to do so successfully. There
can be no assurance that any transgenically produced protein will be safe or
effective. All of the proteins that GTC is developing will require significant
additional research, development and testing and will require the expenditure of
substantial additional capital prior to their commercialization. In addition,
there can be no assurance that research and discoveries by others will not
render GTC's technology obsolete or noncompetitive.

         NO ASSURANCE OF COMMERCIAL SUCCESS OF TRANSGENIC PRODUCTS. The
successful commercialization of any transgenic protein product by the Company
will depend on many factors, including the successful completion of clinical
testing, the response of medical professionals to the data from clinical trials,
the Company's ability to create or access a sales force able to market such
transgenic products, the Company's ability to supply a sufficient amount of
product to meet market demand, the degree to which third-party reimbursement for
use of such product is available and the number and relative efficacy of
competitive products that may subsequently enter the market, as well as, with
respect to transgenic products designed to replace or supplement products
currently being marketed, the relative cost-effectiveness of the

                              Exhibit 99 -- page 2

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transgenic products. There can be no assurance that the Company or its
collaborative partners will be successful in efforts to develop and implement a
commercialization strategy for any such products.

         GTC does not currently have a sales force to market any transgenic
products it may develop. The Company anticipates that, for products it develops
independently, it will enter into marketing arrangements with larger
pharmaceutical or biotechnology companies which have established sales forces
that are able to market such products. There can be no assurance that any
marketing or distribution arrangements will be available on acceptable terms or
that, in the alternative, GTC will be able to establish its own sales force
successfully. Unforeseen delays in this process may have an adverse effect on
the commercialization of any of the Company's products.

         Third-party payors are increasingly attempting to contain health care
costs by limiting both coverage and the level of reimbursement for new
therapeutic products. The successful commercialization of any products developed
by the Company may depend on obtaining coverage and reimbursement for the use of
these products from third-party payors.

         In addition, the successful commercialization of the Company's products
will require that medical professionals become convinced of the efficacy of the
products in treating a particular condition and incorporate such products as
standard practice in relevant therapeutic protocols. There can be no assurance
that any transgenic product developed by GTC will be accepted by the medical
profession.

         GOVERNMENT REGULATION. Transgenic products will require approval by the
U.S. Food and Drug Administration ("FDA") prior to marketing in the United
States. In addition, the manufacturing and marketing of such products, and
certain areas of research related to them, are subject to regulations by other
U.S. governmental authorities including the United States Department of
Agriculture (the "USDA") and the Environmental Protection Agency (the "EPA").
Comparable authorities are involved in other countries.

         In cases where the Company expects to obtain revenue from the sale of
transgenic products, whether through direct sales, marketing relationships with
others or royalty arrangements, the Company will incur the risk of such product
failing to satisfy applicable regulatory requirements prior to marketing. The
approval process involves two parts, governing first the approval of an
individual pharmaceutical product as safe and effective and second the approval
of the manufacturing process as complying with applicable FDA current good
manufacturing practices regulations ("GMPs"). In 1995, the FDA and comparable
European regulatory authorities issued guidelines regarding the production of
therapeutic proteins in transgenic animals. While the FDA's guidelines, known as
Points to Consider guidelines ("Points to Consider"), cover issues specific to
transgenic production, the basic regulatory framework for FDA approval will also
apply to transgenic therapeutic products submitted for approval. To GTC's
knowledge, no protein produced in the milk of a transgenic animal has been
submitted for regulatory approval in the United States or elsewhere.

         The FDA and comparable agencies in foreign countries impose substantial
requirements upon the introduction of therapeutic pharmaceutical products
through lengthy and detailed


                              Exhibit 99 -- page 3

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laboratory and clinical testing procedures, sampling activities and other costly
and time-consuming procedures. Satisfaction of these requirements typically
takes several years or more and can vary substantially based upon the type,
complexity and novelty of the product. With respect to therapeutic products, the
standard FDA approval process includes preclinical laboratory and animal
testing, submission of an IND to the FDA, appropriate human clinical trials to
establish safety and effectiveness and submission of either a Biologics License
Application or a New Drug Application ("NDA") prior to market introduction. With
respect to obtaining approval for the production facilities to be used in
producing a therapeutic product, the Company expects to be subject to both the
requirements for establishment license applications and the Points to Consider
issued with respect to transgenic recombinant products.

         The effect of government regulation may be to delay marketing of the
Company's products for a considerable or indefinite period of time, impose
costly procedural requirements upon the Company's activities and may furnish a
competitive advantage to larger companies or companies more experienced in
regulatory affairs. There can be no assurance that the FDA or other regulatory
approvals for any products developed by the Company will be granted on a timely
basis or at all. Any delay in obtaining or any failure to obtain such approvals
could adversely affect the Company's ability to generate revenue. Even if
initial regulatory approvals for the Company's product candidates are obtained,
the Company, its products and its transgenic manufacturing processes would be
subject to continual review and periodic inspection. There can be no assurance
that the FDA will permit the marketing of any transgenic product for any
particular indication, if at all.

         The Company's operations are also subject to federal, state and local
laws, rules, regulations and policies governing the use, generation,
manufacture, storage, air emission, effluent discharge, handling and disposal of
certain materials and waste, including but not limited to animal waste and waste
water.

         DEPENDENCE OF TESTING SERVICES ON CURRENT GOVERNMENT REGULATORY
REQUIREMENTS. The market for GTC's preclinical testing services is dependent
upon the maintenance of strict standards for the conduct of laboratory and
clinical tests and related procedures which are promulgated by governmental
entities responsible for public health and welfare, including the FDA, and by
regulatory authorities in foreign countries. The process of obtaining these
approvals varies according to the nature and use of the product and routinely
involves lengthy and detailed laboratory and clinical testing and other costly
and time-consuming procedures. The Company offers the customers of its
preclinical testing and development services the necessary expertise to comply
with these complex regulations. If the regulatory structure were to change in a
way which reduced the need for such services, the Company could be materially
adversely affected.

         DEPENDENCE ON GENZYME. GTC has entered into a number of contractual
agreements with Genzyme, including a research and development agreement pursuant
to which Genzyme provides purification services to GTC for transgenically
produced proteins (the "Genzyme R&D Agreement"), a lease of GTC's facility in
Framingham, Massachusetts, and an agreement to provide funding for the
development of AT-III (the "Genzyme Collaboration Agreement").


                              Exhibit 99 -- page 4

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         Under the Genzyme R&D Agreement, Genzyme is obligated to use
commercially reasonable efforts to perform purification services for GTC. GTC
does not currently have personnel capable of undertaking such purification
services. Until such time, if ever, as GTC develops its own capabilities in this
regard, there can be no assurance that Genzyme will be able to provide such
services when and as required by GTC or that GTC would be able to obtain
omparable services elsewhere.

         Under the Genzyme Collaboration Agreement, Genzyme has agreed to
provide funding for transgenic AT-III development in exchange for co-marketing
rights to AT-III in all territories other than Asia. The term of the agreement
is perpetual, except that either party may terminate the agreement for certain
material breaches, failure to make payments, and either upon the grant, or
certain absences of a grant, by the FDA of a license to market an AT-III
product. There can be no assurance, should the agreement terminate before
completion of the development of an AT-III product, that Genzyme and GTC could
reach an agreement to extend Genzyme's development funding, that the Company
would be able to fund such program on its own or that the Company would be able
to obtain such funding from a third party on acceptable terms, if at all.

         POTENTIAL CONFLICTS OF INTEREST WITH GENZYME. Genzyme is the largest
single stockholder of GTC. Assuming exercise of currently exercisable warrants
for 241,000 shares of Common Stock, Genzyme beneficially owns approximately 40%
of the outstanding Common Stock of GTC.

         Genzyme's ownership interest gives it significant influence over any
election of directors and any other action requiring approval by the holders of
a majority of the Common Stock. Three members of GTC's Board of Directors also
serve as directors and/or executive officers of Genzyme. The interests of
Genzyme on the one hand and GTC on the other hand may, from time to time,
differ.

         DEPENDENCE ON COLLABORATORS. The success of GTC's transgenic protein
production business will depend, in large part, on GTC's ability to enter into
arrangements with biotechnology and pharmaceutical companies for the transgenic
production of proteins to which such companies have proprietary rights or to
fund the development of transgenic proteins which are in the public domain or
the subject of expiring patents. To date, the scope of these agreements has
generally been limited to demonstrating the feasibility of transgenic production
of targeted proteins in particular animal species.

         There can be no assurance that these feasibility studies will be
successful or lead to agreements for the commercial production of any proteins.
Depending upon the terms of any future collaborations, the Company's role in
such collaborations may be limited to the production aspects of the proteins
under development. As a result, GTC may also be dependent on collaborators for
other aspects of the development, preclinical and clinical testing, regulatory
approval and commercialization of any transgenic product.

         UNCERTAINTY REGARDING PATENTS AND PROPRIETARY TECHNOLOGY. GTC has
relied upon trade secrets, proprietary know-how and continuing technological
innovation to develop and maintain its competitive position and to protect its
proprietary

                              Exhibit 99 -- page 5

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technology. In part, these legal rights are protected by contracts with
employees, consultants and business partners. There can be no assurance that
trade secrets possessed by GTC will be maintained, that secrecy obligations will
be honored or that others will not independently develop similar or superior
technology. There is no assurance that patent applications filed by GTC will
result in patents being issued or that any patents issued to or licensed by GTC
will be held valid. The Company may also be subject to claims that result in the
revocation of patent rights previously licensed to GTC as a result of which the
Company may be required to obtain licenses from others to continue to develop,
test or commercialize its products. There can be no assurance that GTC will be
able to obtain such licenses on acceptable terms, if at all. In addition, there
may be pending or issued patents held by parties not affiliated with GTC that
relate to the technology utilized by GTC. As a result, GTC may need to acquire
licenses to, or contest the validity of, such patents or any other similar
patents which may be issued. GTC could incur substantial costs in defending
itself against challenges to patent or infringement claims made by third parties
or in enforcing any patent rights of its own. The loss or exposure of trade
secrets possessed by GTC could also adversely affect its business.

         RISK OF SERVICE OR PRODUCT LIABILITY. GTC's business exposes it to
potential product and professional liability risks which are inherent in the
testing, production, marketing and sale of human therapeutic products. While GTC
has obtained product and professional liability insurance under an insurance
policy arrangement with Genzyme and Genzyme's affiliates, there can be no
assurance that such insurance will be sufficient to cover any claim. Uninsured
product or service liability could have a material adverse effect on the
financial results of GTC. In addition, there can be no assurance that any
insurance will provide GTC with adequate protection against potential
liabilities. Potential liability also may arise from the handling by GTC of
clinical samples containing human blood and tissues, which may contain human
pathogens; liability may also 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.

         RETENTION OF KEY PERSONNEL. Although GTC believes that the size and
qualifications of its current staff are adequate for its current business, the
Company must continue to attract and retain qualified scientific, technical,
marketing and management personnel as its business expands. There is intense
competition for qualified personnel in the areas of the Company's activities,
and there can be no assurance that GTC will be able to continue to attract and
retain the qualified personnel necessary for the development of its business.
Loss of the services of, or failure to recruit, key scientific and technical
personnel could have a material adverse effect on GTC's business.

         PUBLIC CONCERNS. Certain of GTC's activities involve animal testing and
genetic engineering in animals. Such activities have been the subject of
controversy and adverse publicity. Animal rights groups and various other
organizations and individuals have attempted to stop animal testing and genetic
engineering activities by pressing for legislation and regulation in these
areas. To the extent the activities of such groups are successful, GTC's
business may be adversely affected.


                              Exhibit 99 -- page 6