Document

WHEREAS, as of the date hereof, Stockholder is the holder of record and/or beneficial owner (as defined in Rule 13d-3 of the Exchange Act) of the shares of Acquirer Stock set forth opposite its name on Schedule I attached hereto (all such shares of Acquirer Stock, together with any additional shares or other voting securities of Acquirer of which such Stockholder acquires record or beneficial ownership after the date of this Agreement, by any means, such Stockholder’s “Shares”);

WHEREAS, contemporaneously with the execution and delivery of this Agreement, Acquirer, Orion Merger Sub I, a Delaware corporation (“Merger Sub I”), Orion Merger Sub II, LLC, a Delaware limited liability company (“Merger Sub II”), GeneDx, Inc., a New Jersey corporation (“Company”), GeneDx Holding 2, Inc., a Delaware corporation (“Holdco2”), and Seller have entered into an Agreement and Plan of Merger and Reorganization (as amended or modified from time to time, the “Merger Agreement”), dated as of the date hereof, pursuant to which, among other transactions, on the Closing Date but following consummation of the Pre-Closing Restructuring, Merger Sub I will merge with and into Holdco2 (the “First Merger”), with Holdco2 as the surviving corporation in the First Merger and Merger Sub I will merge with and into HoldCo2 (the “First Merger”), with HoldCo2 as the surviving corporation in the First Merger, and immediately after the consummation of the First Merger, as part of the same overall transaction, Holdco2, as the surviving corporation in the First Merger, will merge with and into Merger Sub II (the “Second Merger” and, together with the First Merger, the “Mergers”), with Merger Sub II as the surviving corporation and the direct owner of all of the equity interests in GeneDx Delaware LLC.

WHEREAS, on or prior to the date hereof, Acquirer entered into subscription agreements (the “Subscription Agreements” with the PIPE Investors pursuant to which, and on the terms and subject to the conditions of which, such PIPE Investors have agreed to purchase from Acquirer shares of Acquirer Stock for an aggregate purchase price equal to the PIPE Investment Amount, such purchases to be consummated prior to or substantially concurrently with the Closing (the “PIPE Investment,” and, together with the other transactions contemplated by the Merger Agreement, the “Transactions”).

Section 1.1 No Transfer. Stockholder agrees that during the term of this Agreement, Stockholder shall not, directly or indirectly, (a) sell, assign, transfer (including by operation of law), swap, convert, lien, pledge, gift, dispose of or otherwise encumber (including by merger (including by conversion into securities or other consideration), by tendering into any tender or exchange offer, by testamentary disposition, by operation of Law or otherwise, or by divesting itself (pursuant to contract or otherwise) of any rights as a stockholder of Stockholder’s Shares, including, without limitation, the right to vote such Shares) (collectively, a “Transfer”) or enter into any contract or option with respect to the Transfer of, (i) any of

(c) take any action that would make any representation or warranty of such Stockholder contained herein untrue or incorrect or which would have the effect of preventing or disabling Stockholder from performing his, her or its obligations under this Agreement in any material respect; provided that the foregoing shall not prohibit (W) for all purposes of this Section 1(a) from and after the date of the Acquirer Stockholders’ Meeting at which the Requisite Vote is obtained, the Stockholder and its affiliates shall be permitted to Transfer (and enter into any Contract or option with respect to any such Transfer), 100% of the Restricted Amount (such maximum aggregate amount of shares, the “Transferrable Amount”), it being understood and agreed, for the avoidance of doubt, that prior to the date of such Acquirer Stockholders’ Meeting the Stockholder shall not enter into any Contract or option with respect to any such Transfer or publicly disclose, or take any action, that would reasonably be expected to require public disclosure of any intent or plan by Stockholder to engage in any such Transfer (provided that the foregoing shall not restrict the Stockholder from disclosing (including in any filing required by law to be made with the SEC) the existence of this Agreement or the rights of the Stockholder to Transfer Shares in accordance with this Agreement),

(X) the transfer of any of the Shares by Stockholder to any managers, partners, members or other direct or indirect equity holders or affiliates of Stockholder (which, for the avoidance of doubt, shall include any investment fund or managed account that is managed on a discretionary basis by the same investment manager as Stockholder) or to any of its or their officers, directors or employees, but only if any such transferee shall execute a joinder or other instrument agreeing to be bound by the provisions of this Agreement, (Y) any pledge of the Shares in connection with a bona fide margin agreement or grant of a security interest in some or all of the Shares to a financial institution that is an “accredited investor” as defined in Rule 501(a) under the Securities Act, or (Z) any hedging or other transactions, including without limitation any short sales or purchases or sales of “derivative” securities based on securities issued by Acquirer, that do not result in the transfer of any of the Shares or the disposition of voting power in respect thereof prior to the termination of this Agreement. Stockholder hereby covenants and agrees that such Stockholder shall not (i) enter into any voting agreement or voting trust with respect to any of such Stockholder’s Shares that is inconsistent with such Stockholder’s obligations pursuant to this Agreement,

(ii)grant a proxy or power of attorney with respect to any of such Stockholder’s Shares that is inconsistent with such Stockholder’s obligations pursuant to this Agreement or (iii) enter into any agreement or undertaking that is otherwise inconsistent with, or would interfere with, or prohibit or prevent such Stockholder from satisfying its obligations pursuant to this Agreement. In furtherance of the agreements set forth in this Agreement, Stockholder hereby authorizes Acquirer or its counsel to instruct its transfer agent to put in place a stop transfer order with respect to the Restricted Amount except with respect to Transfers of Shares permitted hereby.

Section 1.2 Agreement to Vote. Stockholder hereby unconditionally and irrevocably agrees that, at any meeting of the stockholders of Acquirer however called or at any adjournment thereof, or in any other circumstance that the vote, consent or other approval of the stockholders of Acquirer is sought (the “Requisite Vote”), such Stockholder shall (i) appear at such meeting or otherwise cause all of such Stockholder’s Shares to be counted present thereat for purposes of calculating a quorum and (ii) vote or cause to be voted (or duly and promptly execute and deliver, or cause to be duly and promptly executed and delivered, an action by written consent which written consent shall be delivered promptly, and in any event within three Business Days, after Acquirer, as applicable requests such delivery), all of such Stockholder’s Shares:

Nothing in this Agreement limits or restricts any Affiliate or designee of Stockholder who serves as a member of the Acquirer Board in acting or voting in his or her capacity as a director of Acquirer and exercising his or her fiduciary duties and responsibilities, it being understood that this Agreement applies to Stockholder solely in its capacity as a stockholder of Acquirer and does not apply to any such Affiliate or designee’s actions, judgments or decisions as a director of Acquirer, and such actions (or failures to act) shall not be deemed to constitute a breach of this Agreement.

(a)Solely in furtherance of Section 1.2 of this Agreement and subject to termination as provided in Section 3.1 of this Agreement, Stockholder (i) hereby irrevocably grants to, and appoints, Acquirer or any individual designated by Acquirer as the Stockholder’s agent, irrevocable proxy and attorney-in-fact (with full power of substitution and resubstitution) to vote the Shares, provide written consents, express consent or otherwise utilize voting power as indicated in Section 1.2 of this Agreement; provided, however, that Stockholder’s grant of the proxy contemplated by this Section 1.3(a) shall be effective if, and only if, Stockholder has not delivered to the Secretary of Acquirer at least five Business Days prior to such meeting a duly executed proxy card previously approved by Acquirer voting Stockholder’s Shares in the manner specified in Section 1.2 or in the event such proxy card has been thereafter modified or revoked or otherwise fails to provide evidence of Stockholder’s compliance with its obligations under Section 1.2 in form and substance reasonably acceptable to Acquirer, (ii) hereby affirms that the irrevocable proxy set forth in this Section 1.3, if it becomes effective pursuant to clause (i), is given in connection with the execution of the Merger Agreement, and that such irrevocable proxy is given to secure the performance of the duties of Stockholder under this Agreement and (iii) hereby (a) affirms that the irrevocable proxy is coupled with an interest and (b) affirms that such irrevocable proxy, if it becomes effective pursuant to clause (i), is executed and intended to be irrevocable in accordance with the provisions of Section 212(e) of the General Corporation Law of the State of Delaware.

(b)Stockholder hereby represents that all proxies, powers of attorney, instructions or other requests given by Stockholder prior to the execution of this Agreement in respect of the voting of Stockholder’s Shares, if any, are not irrevocable and Stockholder hereby revokes (or causes to be revoked) any and all previous proxies, powers of attorney, instructions or other requests with respect to Stockholder’s Shares. The vote, if any, of the proxy holder pursuant to the proxy set forth in this Section 1.3 shall control the outcome, and be determinative, of any conflict between the vote by the proxy holder of the Shares and a vote by a Stockholder of the Shares. Stockholder shall provide evidence to Acquirer in connection with the actions of the Stockholder under or relating to this Section 1.3 as Acquirer shall reasonably request.

Section 1.5 No Ownership Interest. Nothing contained in this Agreement shall be deemed to vest in the Acquirer Parties any direct or indirect ownership or incidence of ownership of or with respect to any Shares, except as expressly provided herein. All rights, ownership and economic benefits of and relating to the Shares shall remain vested in and belong to Stockholder, and neither Acquirer nor Merger Subs shall have any authority to direct Stockholder in the voting or disposition of any of the Shares, except as otherwise provided herein.

Section 1.7 Consent to Disclosure. Stockholder hereby consents to the publication and disclosure required by applicable securities Laws or the SEC or any other securities authorities, any other documents or communications provided by Acquirer to any Governmental Authority of such Stockholder’s identity and beneficial ownership of Shares and the nature of such Stockholder’s commitments, arrangements and understandings under and relating to this Agreement and, if deemed appropriate by Acquirer, a form of this Agreement. Stockholder will promptly provide any information reasonably requested by Acquirer that is necessary for any regulatory application or filing made or approval sought in connection with the Transactions (including filings with the SEC). The Acquirer shall provide Stockholder with a reasonable opportunity to review and comment on any disclosure made in accordance with Section 1.7 and shall consider in good faith any comments of Stockholder, and the Acquirer shall not make any substantive revision to information regarding Stockholder that is provided by Stockholder for inclusion in any filing with the SEC without Stockholder’s approval, which shall not be unreasonably withheld, delayed or conditioned.

(a)Organization; Due Authorization. If such Stockholder is not a natural person, it is duly organized, validly existing and in good standing under the Laws of the jurisdiction in which it is incorporated, formed, organized or constituted, and the execution, delivery and performance of this Agreement and the consummation of the transactions contemplated hereby are within such Stockholder’s corporate, limited liability company or organizational powers and have been duly authorized by all necessary corporate, limited liability company or organizational actions on the part of such Stockholder. If such Stockholder is a natural person, such Stockholder has full legal capacity, right and authority to execute and deliver this Agreement and to perform his or her obligations hereunder. This Agreement has been duly executed and delivered by such Stockholder and, assuming due authorization, execution and delivery by the other parties to this Agreement, this Agreement constitutes a legally valid and binding obligation of such Stockholder, enforceable against such Stockholder in accordance with the terms hereof (except as enforceability may be limited by bankruptcy Laws, other similar Laws affecting creditors’ rights and general principles of equity affecting the availability of specific performance and other equitable remedies). If this Agreement is being executed in a representative or fiduciary capacity, the Person signing this

(b)Ownership. Such Stockholder is the record and/or beneficial owner (as defined in Rule 13d-3 of the Exchange Act) of, and has good title to, all of such Stockholder’s Shares, and there exist no encumbrances or any other limitation or restriction (including any restriction on the right to vote, sell or otherwise dispose of such Shares (other than transfer restrictions under the Securities Act)) affecting any such Shares, other than encumbrances pursuant to (i) this Agreement, (ii) the certificate of incorporation of Acquirer, (iii) the Merger Agreement, (iv) pursuant to any existing lock-up agreement, (v) any applicable securities Laws or (vi) that would not prevent, enjoin or delay in any manner Stockholder’s performance of its obligations under this Agreement. Such Stockholder’s Shares are the only equity securities in Acquirer owned of record or beneficially by such Stockholder on the date of this Agreement, and none of such Stockholder’s Shares are subject to any proxy, voting trust or other agreement or arrangement with respect to the voting of such Shares, except as provided hereunder and under the certificate of incorporation of Acquirer or as noted on Schedule I. Such Stockholder does not hold or own any rights to acquire (directly or indirectly) any equity securities of Acquirer or any equity securities convertible into, or which can be exchanged for, equity securities of Acquirer other than warrants issued by the Acquirer prior to the date of this Agreement or earn-out shares issuable pursuant to the Agreement and Plan of Merger by and among Acquirer, S-IV Sub, Inc. and Mount Sinai Genomics, Inc. dated as of February 9, 2021, as amended.

(c)No Conflicts. The execution and delivery of this Agreement by such Stockholder does not, and the performance by such Stockholder of his, her or its obligations hereunder will not, (i) if such Stockholder is not an individual, conflict with or result in a violation of the organizational documents of such Stockholder or (ii) require any consent or approval that has not been given or other action that has not been taken by any Person (including under any Contract binding upon such Stockholder or such Stockholder’s Shares) to the extent such consent, approval or other action would prevent, enjoin or materially delay the performance by such Stockholder of its, his or her obligations under this Agreement.

Section 3.1 Termination. All of the provisions this Agreement (and the proxy granted hereunder) shall terminate and be of no further force or effect upon the earlier of (a) the Effective Time, (b) such date and time as the Merger Agreement shall be terminated in accordance with Section 7.1 thereof (the earlier of clause (a) and (b) being the “Expiration Time”) and (c) the written agreement of Acquirer, Seller and Stockholder to terminate the provisions of this Agreement. Stockholder shall also have the right to

terminate this Agreement (and the proxy granted hereunder) by written notice to Acquirer if the Transactions have not been consummated by the Outside Date (as defined in the Subscription Agreements). Upon any termination of this Agreement, all obligations of Acquirer and Stockholder under this Agreement will terminate, without any liability or other obligation on the part of any party hereto to any person or entity in respect hereof or the transactions contemplated hereby, and no party hereto shall have any claim against another (and no person or entity shall have any rights against such party), whether under contract, tort or otherwise, with respect to the subject matter hereof; provided, however, that the termination of the provisions of this Agreement shall not relieve any party hereto from liability arising in respect of any willful breach of the provisions of this Agreement prior to such termination. Stockholder’s obligations under Section 1.2 and 1.3 shall cease to apply, and the proxy granted under Section 1.3 shall terminate, in the event that the Merger Agreement is amended, modified, supplemented or waived in a manner that (A) increases the Stock Consideration, otherwise materially changes the form, or otherwise materially increases the amount, of the consideration payable by Acquirer pursuant to the Merger Agreement, (B) changes the definition of Specified Designees or (C) is otherwise materially adverse to Stockholder, unless Stockholder has consented to such amendment, modification, supplement or waiver in writing (which consent will not be unreasonably withheld, delayed or conditioned if so requested by Acquirer). This ARTICLE III shall survive the termination of this Agreement.

Section 3.2 Other Agreements. Acquirer represents and warrants to Stockholder that it has obtained a binding support agreement or commitment from the stockholders listed in Schedule II (each a “Supporting Stockholder”) in respect of the Requisite Vote with substantially the same commitment and terms, including restrictions on transfer as noted in such Schedule, set forth in this Agreement (each a “Supporting Stockholder Voting Commitment”). Acquirer shall not agree to any amendment, waiver, termination or modification of a material term of a Supporting Stockholder Voting Commitment without offering the same amendment, waiver, termination or modification to Stockholder. The obligations of each Supporting Stockholder under any Supporting Stockholder Voting Commitment are several and not joint with the obligations of any other Supporting Stockholder, and no Supporting Stockholder shall be responsible in any way for the performance of the obligations of any other Supporting Stockholder under any Supporting Stockholder Voting Commitment. Nothing contained herein or in any other Supporting Stockholder Voting Commitment , and no action taken by any Supporting Stockholder pursuant hereto or thereto, shall be deemed to constitute the Supporting Stockholders and Stockholder as, and Acquirer acknowledges that the Supporting Stockholders and Stockholder do not so constitute, a partnership, an association, a joint venture or any other kind of entity, or create a presumption that the Supporting Stockholders and Stockholder are in any way acting in concert or as a group, and no party hereto will assert any such claim with respect to such obligations or the transactions contemplated hereby or by the Supporting Stockholder Voting Commitments. Acquirer acknowledges and Stockholder confirms that it has independently participated in the negotiation of the transaction contemplated hereby with the advice of its own counsel and advisors. Stockholder shall be entitled to independently protect and enforce its rights, including, without limitation, the rights arising out of this Agreement, and shall not seek, nor shall it be necessary for, any Supporting Stockholder to be joined as an additional party in any proceeding for such purpose.

Section 3.3 Injunctive Relief; Specific Performance. The parties hereto agree that irreparable damage would occur if any provision of this Agreement were not performed in accordance with the terms hereof, and, accordingly, that the parties hereto shall, to the fullest extent permitted by Law, be entitled to an injunction or injunctions to prevent breaches of this Agreement or to enforce specifically the performance of the terms and provisions hereof in the Court of Chancery of the State of Delaware or, if that court does not have jurisdiction, any federal court located in the State of Delaware or any other Delaware State Court without proof of actual damages or otherwise, in addition to any other remedy to which they are entitled at law or in equity as expressly permitted in this Agreement. To the fullest extent permitted by applicable Law, each of the parties hereto hereby further waives (a) any defense in any Proceeding for

specific performance that a remedy at law would be adequate and (b) any requirement under any Law to post security or a bond as a prerequisite to obtaining equitable relief. Each of the parties hereto hereby acknowledges and agrees that it may be difficult to prove damages with reasonable certainty, that it may be difficult to procure suitable substitute performance, and that injunctive relief and/or specific performance will not cause an undue hardship to the parties hereto. Each of the parties hereto hereby further acknowledges that the existence of any other remedy contemplated by this Agreement does not diminish the availability of specific performance of the obligations hereunder or any other injunctive relief. Each party hereto hereby further agrees that in the event of any action by any other party for specific performance or injunctive relief, such party will not assert that a remedy at law or other remedy would be adequate or that specific performance or injunctive relief in respect of such breach or violation should not be available on the grounds that money damages are adequate or any other grounds

Section 3.4 Governing Law; Jurisdiction; Waiver of Jury Trial. This Agreement shall be governed by, and construed in accordance with, the Laws of the State of Delaware applicable to contracts executed in and to be performed in that State. Any Proceeding arising out of or relating to this Agreement or the transactions contemplated hereby shall, to the fullest extent permitted by applicable Law, be heard and determined exclusively in the Court of Chancery of the State of Delaware; provided, that if jurisdiction is not available in such court, then any such legal Proceeding may be brought in any federal court located in the State of Delaware or any other Delaware state court. To the fullest extent permitted by applicable Law, the parties hereto hereby (i) irrevocably submit to the exclusive jurisdiction of the aforesaid courts for themselves and with respect to their respective properties for the purpose of any Proceeding arising out of or relating to this Agreement or the transactions contemplated hereby brought by any party hereto, and

(ii) agree not to commence any such Proceeding except in the courts described above in Delaware, other than any Proceeding in any court of competent jurisdiction to enforce any judgment, decree or award rendered by any such court in Delaware as described herein. To the fullest extent permitted by applicable Law, each of the parties hereto further agrees that notice as provided herein shall constitute sufficient service of process and the parties hereto further waive any argument that such service is insufficient. To the fullest extent permitted by applicable Law, each of the parties hereto hereby irrevocably and unconditionally waives, and agrees not to assert, by way of motion or as a defense, counterclaim or otherwise, in any Proceeding arising out of or relating to this Agreement or the transactions contemplated hereby, (x) any claim that such party is not personally subject to the jurisdiction of the courts in Delaware as described herein for any reason, (y) that such party or such party’s property is exempt or immune from jurisdiction of any such court or from any legal process commenced in such courts (whether through service of notice, attachment prior to judgment, attachment in aid of execution of judgment, execution of judgment or otherwise) and (z) that (A) the Proceeding in any such court is brought in an inconvenient forum, (B) the venue of such Proceeding is improper or (C) this Agreement or the transactions contemplated hereby, or the subject matter hereof, may not be enforced in or by such courts. EACH PARTY HERETO HEREBY IRREVOCABLY AND UNCONDITIONALLY WAIVES, TO THE FULLEST EXTENT PERMITTED BY APPLICABLE LAW, ANY AND ALL RIGHT TO A TRIAL BY JURY IN ANY PROCEEDING DIRECTLY OR INDIRECTLY ARISING OUT OF OR RELATED TO THIS AGREEMENT OR THE TRANSACTIONS CONTEMPLATED HEREBY. EACH PARTY HERETO CERTIFIES AND ACKNOWLEDGES THAT (I) NO REPRESENTATIVE, AGENT OR ATTORNEY OF ANY OTHER PARTY HAS REPRESENTED, EXPRESSLY OR OTHERWISE, THAT SUCH PARTY WOULD NOT, IN THE EVENT OF LITIGATION, SEEK TO ENFORCE EITHER OF SUCH WAIVERS, (II) IT UNDERSTANDS AND HAS CONSIDERED THE IMPLICATIONS OF SUCH WAIVERS, (III) IT MAKES SUCH WAIVERS VOLUNTARILY AND (IV) IT HAS BEEN INDUCED TO ENTER INTO THIS AGREEMENT, BY, AMONG OTHER THINGS, THE MUTUAL WAIVER AND CERTIFICATIONS IN THIS SECTION.

Section 3.6 Amendment; Waiver; Severability. This Agreement may not be amended, changed, supplemented, waived or otherwise modified or terminated, except upon the execution and delivery of a written agreement executed by the parties to this Agreement. If any term or other provision of this Agreement is invalid, illegal or incapable of being enforced by any rule of law, or public policy, all other conditions and provisions of this Agreement shall nevertheless remain in full force and effect so long as the economic or legal substance of the transactions contemplated hereby is not affected in any manner materially adverse to any party. Upon such determination that any term or other provision is invalid, illegal or incapable of being enforced, the parties hereto shall negotiate in good faith to modify this Agreement so as to effect the original intent of the parties as closely as possible in a mutually acceptable manner in order that the transactions contemplated hereby be consummated as originally contemplated to the fullest extent possible.