AMENDED AND RESTATED NON-RECOURSE PROMISSORY NOTE


$479,880                                                      Reykjavik, Iceland
                                                                  March 24, 1999

         FOR VALUE RECEIVED, the undersigned hereby unconditionally promises to
pay to the order of deCODE genetics, Inc., a Delaware corporation (the
"Company"), at the Company's principal office or at such other place as the
holder hereof may designate in writing, on 1 February, 2003, in lawful money of
the United States of America and in immediately available funds, the total price
of 479,880 Dollars ($479,880), together with interest, compounded annually,
from 16 November, 1998 on the unpaid principal at the rate of 6% per annum.

         This Note may not be prepaid.

         The full amount of this Note is secured by a pledge of shares of Common
Stock of the Company, and is subject to all of the terms and provisions of the
Amended and Restated Early Exercise Stock Purchase Agreement and the Amended and
Restated Pledge Agreement, each of even date herewith between the undersigned
and the Company. The Company's recovery against the undersigned for failure to
pay any amount owing hereunder when due shall be limited solely to the shares of
Common Stock or other collateral of the undersigned pledged to the Company in
the Amended and Restated Pledge Agreement. The undersigned shall not be liable
or have any personal liability in any other respect for the payment of any
amount due under this Note.

         The undersigned hereby represents and agrees that the amounts due under
this Note are not consumer debt, and are not incurred primarily for personal,
family or household purposes, but are for business and commercial purposes only.

         The undersigned hereby waives presentment, protest and notice of
protest, demand for payment, notice of dishonor and all other notices or demands
in connection with the delivery, acceptance, performance, default or endorsement
of this Note.

         This Note shall be governed by, and construed, enforced and interpreted
in accordance with, the laws of the State of Delaware, excluding conflict of
laws principles that would cause the application of laws of any other
jurisdiction.


<PAGE>   2




         This Amended and Restated Non-Recourse Promissory Note reflects
amendments to the Non-Recourse Promissory Note delivered to the Company by the
undersigned on 16 November, 1998, which amendments were agreed upon between the
Company and the undersigned on March 24, 1999. It supersedes and replaces in all
respects such Non-Recourse Promissory Note.

                                            /s/    Sigurdur I. Bjornsson
                                            ------------------------------------
                                                       (signature)

                                                   Sigurdur I. Bjornsson
                                            ------------------------------------
                                                      (print name)

Source: OneCLE Business Contracts.