LIMITED POWER OF ATTORNEY FOR SECTION 16 REPORTING OBLIGATIONS

	Know all by these present, that the undersigned hereby makes,
constitutes and appoints each of Shalini Sharp and Ryan Murr signing
singly and each acting individually, as the undersigned's true and
lawful attorney in fact with full power and authority as hereinafter
described to:

1)	execute for and on behalf of the undersigned, in the
undersigned's capacity as an officer and/or director and/or
stockholder of Ultragenyx Pharmaceutical Inc. (the Company), Forms 3,
4, and 5 (including any amendments thereto) in accordance with
Section 16(a) of the Securities Exchange Act of 1934 and the rules
thereunder (the Exchange Act);

2)	do and perform any and all acts for and on behalf of the
undersigned which may be necessary or desirable to prepare, complete,
and execute any such Form 3, 4, or 5, prepare, complete, and execute
any amendment or amendments thereto, and deliver and file such form(s)
with the United States Securities and Exchange Commission (the SEC)
and any stock exchange or similar authority, including without limitation
the filing of a Form ID or any other application materials to enable the
undersigned to gain or maintain access to the Electronic Data Gathering,
Analysis, and Retrieval system of the SEC;

3)	seek or obtain, as the undersigned's representative and on the
undersigned's behalf, information regarding transactions in the Company's
securities from any third party, including brokers, employee benefit
plan administrators, and trustees, and the undersigned hereby authorizes
any such person to release any such information to such attorney in fact
and approves and ratifies any such release of information; and

4)	take any other action of any type whatsoever in connection with
the foregoing which, in the opinion of such attorney in fact, may be of
benefit to, in the best interest of, or legally required by, the
undersigned, it being understood that the documents executed by such
attorney in fact on behalf of the undersigned pursuant to this Power
of Attorney shall be in such form and shall contain such terms and
conditions as such attorney in fact may approve in such attorney in
facts discretion.

	The undersigned hereby grants to each such attorney in fact
full power and authority to do and perform any and every act and thing
whatsoever requisite, necessary, or proper to be done in the exercise
of any of the rights and powers herein granted, as fully to all intents
and purposes as the undersigned might or could do if personally present,
with full power of substitution or revocation, hereby ratifying and
confirming all that such attorney in fact, or such attorney in fact's
substitute or substitutes, shall lawfully do or cause to be done by
virtue of this power of attorney and the rights and powers herein granted.
The undersigned acknowledges that the foregoing attorneys in fact,
in serving in such capacity at the request of the undersigned, are not
assuming nor relieving, nor is the Company assuming nor relieving, any
of the undersigned's responsibilities to comply with Section 16 of the
Exchange Act. The undersigned acknowledges that neither the Company nor
the foregoing attorneys in fact assume (i) any liability for the
undersigned's responsibility to comply with the requirement of the
Exchange Act, (ii) any liability of the undersigned for any failure to
comply with such requirements, or (iii) any obligation or liability
of the undersigned for profit disgorgement under Section 16(b) of the
Exchange Act.

	This Power of Attorney shall remain in full force and effect
until the undersigned is no longer required to file Forms 3, 4, and 5
with respect to the undersigned's holdings of and transactions in
securities issued by the Company, unless earlier revoked by the
undersigned in a signed writing delivered to the foregoing attorneys
in fact.

	IN WITNESS WHEREOF, the undersigned has caused this Power of
Attorney to be executed as of this 20th day of June, 2016.





/s/ Karah Parschauer
Signature

Karah Parschauer