FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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(Print or Type Responses)

1. Name and Address of Reporting Person * SCHMERTZLER MICHAEL   2. Issuer Name and Ticker or Trading Symbol PTC THERAPEUTICS, INC. [PTCT] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) __X__ Director __X__ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) 1300 VALLEY ROAD 3. Date of Earliest Transaction (Month/Day/Year) 01/29/2013 (Street) NEW CANAAN, CT 06840 4. If Amendment, Date Original Filed(Month/Day/Year) 6. Individual or Joint/Group Filing(Check Applicable Line) _X_ Form filed by One Reporting Person ___ Form filed by More than One Reporting Person (City) (State) (Zip) Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned

1.Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock               26,766 D   Common Stock 06/25/2013   C   155,366 A (1) 155,366 I See footnotes (2) (9) Common Stock 06/25/2013   C   608,670 A (1) 764,036 I See footnotes (2) (9) Common Stock 06/25/2013   P   533,333 A $ 15 1,297,369 I See footnotes (2) (9)

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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Underlying Securities (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
8% Convertible Promissory Notes	(3)	01/29/2013		P		$ 204,724		(3)	(3)	Series Four Senior Preferred Stock	(3)	(3)	$ 204,724	I	See footnotes (2) (9)
Warrant (right to purchase)	$ 0.01	01/29/2013		P		52,736		01/29/2014	01/29/2020	Series One Preferred Stock	52,736	$ 0.01	52,736	I	See footnotes (2) (9)
Warrant (right to purchase)	$ 0.01	01/29/2013		P		206,003		01/29/2014	01/29/2020	Series Two Preferred Stock	206,003	$ 0.01	206,003	I	See footnotes (2) (9)
8% Convertible Promissory Notes	(3)	02/15/2013		P		$ 409,448		(3)	(3)	Series Four Senior Preferred Stock	(3)	(3)	$ 614,172	I	See footnotes (2) (9)
Series Four Senior Preferred Stock	(1)	03/07/2013		P		103,819		(1)	(1)	Common Stock	103,819	$ 12	103,819	I	See footnotes (2) (9)
8% Convertible Promissory Notes	(3)	03/07/2013		C			$ 618,569.36	(3)	(3)	Series Four Senior Preferred Stock	51,547	(3)	0	I	See footnotes (2) (9)
Series Four Senior Preferred Stock	(1)	03/07/2013		C		51,547		(1)	(1)	Common Stock	51,547	(1)	155,366	I	See footnotes (2) (9)
Series One Preferred Stock	(4)	03/07/2013		J(4)			110,000	(4)	(4)	Common Stock	110,000	(4)	0	I	See footnotes (2) (9)
Series One Preferred Stock	(4)	03/07/2013		J(4)		394,166		(4)	(4)	Series Five Junior Preferred Stock	394,166	(4)	394,166	I	See footnotes (2) (9)
Series One Preferred Stock	(4)	03/07/2013		J(4)			394,166	(4)	(4)	Series Five Junior Preferred Stock	394,166	(4)	0	I	See footnotes (2) (9)
Series Five Junior Preferred Stock	(1)	03/07/2013		J(4)		394,166		(1)	(1)	Common Stock	394,166	(1)	394,166	I	See footnotes (2) (9)
Warrant (right to purchase)	$ 0.01	03/07/2013		J(4)			52,736	01/29/2014	01/29/2020	Series One Preferred Stock	52,736	(4)	0	I	See footnotes (5) (9)
Warrant (right to purchase)	$ 0.0028	03/07/2013		J(4)		188,970		01/29/2014	01/29/2020	Series Five Junior Preferred Stock	188,970	$ 0.0028	188,970	I	See footnotes (5) (9)
Warrant (right to purchase)	$ 0.0028	03/07/2013		S(5)			44	01/29/2014	01/29/2020	Series Five Junior Preferred Stock	44	$ 0.0028	188,926	I	See footnotes (5) (9)
Warrant (right to purchase)	$ 0.0028	03/07/2013		C			188,926	01/29/2014	01/29/2020	Series Five Junior Preferred Stock	188,926	$ 0.0028	0	I	See footnotes (5) (9)
Series Five Junior Preferred Stock	(1)	03/07/2013		C		188,926		(1)	(1)	Common Stock	188,926	(1)	583,092	I	See footnotes (5) (9)
Warrant (right to purchase)	$ 0.01	03/07/2013		J(6)			206,003	01/29/2014	01/29/2020	Series Two Preferred Stock	206,003	(6)	0	I	See footnotes (7) (9)
Warrant (right to purchase)	$ 0.08	03/07/2013		J(6)		25,750		01/29/2014	01/29/2020	Series Five Junior Preferred Stock	25,570	$ 0.08	25,750	I	See footnotes (7) (9)
Warrant (right to purchase)	$ 0.08	03/07/2013		S(7)			172	01/29/2014	01/29/2020	Series Five Junior Preferred Stock	172	$ 0.08	25,578	I	See footnotes (7) (9)
Warrant (right to purchase)	$ 0.08	03/07/2013		C			25,578	01/29/2014	01/29/2020	Series Five Junior Preferred Stock	25,578	$ 0.08	0	I	See footnotes (7) (9)
Series Five Junior Preferred Stock	(1)	03/07/2013		C		25,578		(1)	(1)	Common Stock	25,578	(1)	608,670	I	See footnotes (7) (9)
Series Four Senior Preferred Stock	(1)	06/25/2013		C			155,366	(1)	(1)	Common Stock	155,366	(1)	0	I	See footnotes (2) (9)
Series Five Junior Preferred Stock	(1)	06/25/2013		C			608,670	(1)	(1)	Common Stock	608,670	(1)	0	I	See footnotes (2) (9)
Stock Option (right to buy)	$ 10.85	05/15/2013		P			60,000	(8)	05/15/2023	Common Stock	60,000	$ 10.85	60,000	D

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
SCHMERTZLER MICHAEL 1300 VALLEY ROAD NEW CANAAN, CT 06840	X	X

Signatures

/s/ Mark E. Boulding, attorney-in-Fact		06/27/2013
**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 4(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1)	Each share of Series Four Senior Preferred Stock and each share of Senior Five Junior Preferred Stock converted automatically into one share of Common Stock upon the closing of PTC Therapeutics, Inc.'s initial public offering without payment of further consideration. The Series Four Senior Preferred Stock and the Series Five Junior Preferred Stock had no expiration date.
(2)	Securities held by Section Six Partners, L.P.
(3)	The convertible promissory notes issued as part of PTC Therapeutics, Inc.'s bridge financing in January and February 2013 were (1) payable upon demand of the holders at any time on or after the first anniversary of the date of issuance and (2) convertible into shares of the same class and series of capital stock of PTC Therapeutics, Inc. issued to other investors in the next qualified financing (with gross proceeds of at least $20 million) at a conversion price equal to the price per share paid by other investors in such financing.
(4)	In connection with a recapitalization and reverse stock split that occurred on March 7, 2013, each share of Series One Preferred Stock converted automatically into a number of shares of Series Five Junior Preferred Stock equal to a fraction, the numerator of which was 430 and the denominator of which was 120, without payment of further consideration. Warrants to purchase shares of Series One Preferred Stock were automatically adjusted to be exercisable into shares of Series Five Junior Preferred Stock at the applicable conversion ratio. The Series One Preferred Stock had no expiration date.
(5)	On March 7, 2013, the warrants to purchase shares of Series One Preferred Stock were automatically adjusted to be exercisable into shares of Series Five Junior Preferred Stock at the applicable conversion ratio, and were automatically exercised for shares of Series Five Junior Preferred Stock without further action by the holders thereof at the as-adjusted exercise price of $12 a share. The exercise price was paid on a cashless basis, resulting in PTC Therapeutics, Inc. withholding 44 of the reporting person's warrant shares to pay the exercise price and issuing to the reporting person the remaining 188,926 shares of Series Five Junior Preferred Stock. PTC Therapeutics, Inc. also paid $8.64 to the reporting person in lieu of fractional shares. The warrant shares are held by Section Six Partners, L.P.
(6)	In connection with a recapitalization and reverse stock split that occurred on March 7, 2013, each share of Series Two Preferred Stock converted automatically into a number of shares of Series Five Junior Preferred Stock equal to a fraction, the numerator of which was 15 and the denominator of which was 120, without payment of further consideration. Warrants to purchase shares of Series Two Preferred Stock were automatically adjusted to be exercisable into shares of Series Five Junior Preferred Stock at the applicable conversion ratio. The Series Two Preferred Stock had no expiration date.
(7)	On March 7, 2013, the warrants to purchase shares of Series Two Preferred Stock were automatically adjusted to be exercisable into shares of Series Five Junior Preferred Stock at the applicable conversion ratio, and were automatically exercised for shares of Series Five Junior Preferred Stock without further action by the holders thereof at the as-adjusted exercise price of $12 a share. The exercise price was paid on a cashless basis, resulting in PTC Therapeutics, Inc. withholding 172 of the reporting person's warrant shares to pay the exercise price and issuing to the reporting person the remaining 25,578 shares of Series Five Junior Preferred Stock. PTC Therapeutics, Inc. also paid $8.47 to the reporting person in lieu of fractional shares. The warrant shares are held by Section Six Partners, L.P.
(8)	This option was granted on May 15, 2013 and vests over three years, with 8.33% of the shares underlying the option vesting on August 15, 2013 and an additional 8.33% of the original number of shares underlying the option vesting at the end of each successive three-month period thereafter.
(9)	Mr. Schmertzler is a general and limited partner of, and trustee of certain family trusts holding interests in, Section Six Partners, L.P. Mr. Schmertzler disclaims beneficial ownership of the shares held by Section Six Partners, L.P. except to the extent of any pecuniary interest therein.
Remarks: This Form 4 is being filed in two parts, of which this is the first of two.

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