CERTIFICATE OF AMENDMENT

TO

AMENDED AND RESTATED CERTIFICATE OF INCORPORATION

OF

PRAXIS PRECISION MEDICINES, INC.

Pursuant to Section 242 of the

General Corporation Law of the State of Delaware

Praxis Precision Medicines, Inc. (the “Corporation”), a corporation organized and existing under and by virtue of the provisions of the General Corporation Law of the State of Delaware,

DOES HEREBY CERTIFY THAT:

1.That the Board of Directors of the Corporation duly adopted resolutions recommending and declaring advisable that the Amended and Restated Certificate of Incorporation of the Corporation, be further amended and that such amendment be submitted to the stockholders of the Corporation for their consideration, as follows:

RESOLVED, that the following paragraph be inserted immediately prior to the first sentence of Article IV of the Amended and Restated Certificate of Incorporation:

“Effective at 5:00 p.m., Eastern time, on the date this Certificate of Amendment to the Amended and Restated Certificate of Incorporation is filed with the Secretary of State of the State of Delaware (the “Effective Time”), a one-for-15 reverse stock split of the Common Stock (as defined below) shall become effective, pursuant to which each 15 shares of Common Stock issued and held of record by each stockholder of the Corporation immediately prior to the Effective Time shall be reclassified and combined into one validly issued, fully paid and nonassessable share of Common Stock automatically and without any action by the holder thereof upon the Effective Time and shall represent one share of Common Stock from and after the Effective Time (such reclassification and combination of shares, the “Reverse Stock Split”). No fractional shares of Common Stock shall be issued as a result of the Reverse Stock Split and, in lieu thereof, (a) with respect to holders of one or more certificates, if any, which formerly represented shares of Common Stock that were issued and outstanding immediately prior to the Effective Time, upon surrender after the Effective Time of such certificate or certificates, any holder who would otherwise be entitled to a fractional share of Common Stock as a result of the Reverse Stock Split, following the Effective Time, shall be entitled to receive a cash payment (the “Fractional Share Payment”) equal to the fraction of which such holder would otherwise be entitled multiplied by the closing price per share of Common Stock on the date of the Effective Time as reported by The Nasdaq Global Select Market (as adjusted to give effect to the Reverse Stock Split); provided that, whether or not fractional shares would be issuable as a result of the Reverse Stock Split shall be determined on the basis of (i) the total number of shares of Common Stock that were issued and outstanding immediately prior to the Effective Time formerly represented by certificates that the holder is at the time surrendering and (ii) the aggregate number of shares of Common Stock after the Effective Time into which the shares of Common Stock formerly represented by such certificates shall have been reclassified; and (b) with respect to holders of shares of Common Stock in book-entry form in the records of the Corporation’s transfer agent that were issued and outstanding immediately prior to the Effective Time, any holder who would otherwise be entitled to a fractional share of Common Stock as a result of the

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Reverse Stock Split (after aggregating all fractional shares), following the Effective Time, shall be entitled to receive the Fractional Share Payment automatically and without any action by the holder.”

2.That, at a meeting of stockholders of the Corporation, the aforesaid amendment was duly adopted by the stockholders of the Corporation.

3.That the aforesaid amendment was duly adopted in accordance with the applicable provisions of Section 242 of the General Corporation Law of the State of Delaware.

IN WITNESS WHEREOF, the Corporation has caused this Certificate of Amendment to be signed by its President on this 28th day of November 2023.

PRAXIS PRECISION MEDICINES, INC.

By: __/s/ Marcio Souza____________

Name: Marcio Souza

Title: President

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