Filing Details

SCHEDULE 13G Amendment No. 0 DIMENSION THERAPEUTICS INC COMMON STOCK Cusip #25433V105 Check the appropriate box to designate the rule pursuant to which this Schedule is filed: [ ] Rule 13d-1(b) [x] Rule 13d-1(c) [ ] Rule 13d-1(d) Cusip #25433V105 Item 1: Reporting Person - FIL Limited Item 2: (a) [ ] (b) [ ] Item 4: Bermuda Item 5: 2,066,979 Item 6: 0 Item 7: 2,066,979 Item 8: 0 Item 9: 2,066,979 Item 11: 8.261% Item 12: FI Cusip #25433V105 Item 1: Reporting Person - Pandanus Partners, L.P. Item 2: (a) [ ] (b) [ ] Item 4: Delaware Item 5: 0 Item 6: 0 Item 7: 2,066,979 Item 8: 0 Item 9: 2,066,979 Item 11: 8.261% Item 12: PN Cusip #25433V105 Item 1: Reporting Person - Pandanus Associates, Inc. Item 2: (a) [ ] (b) [ ] Item 4: Delaware Item 5: 0 Item 6: 0 Item 7: 2,066,979 Item 8: 0 Item 9: 2,066,979 Item 11: 8.261% Item 12: CO Item 1(a). Name of Issuer: DIMENSION THERAPEUTICS INC Item 1(b). Address of Issuer's Principal Executive Offices: 840 MEMORIAL DRIVE 4TH FLOOR CAMBRIDGE, MA 02139 USA Item 2(a). Name of Person Filing: FIL Limited Item 2(b). Address or Principal Business Office or, if None, Residence: Pembroke Hall, 42 Crow Lane, Hamilton, Bermuda, HM19 Item 2(c). Citizenship: Not applicable Item 2(d). Title of Class of Securities: COMMON STOCK Item 2(e). CUSIP Number: 25433V105 Item 3. Not Applicable Item 4. Ownership (a) Amount Beneficially Owned: 2,066,979 (b) Percent of Class: 8.261% (c) Number of shares as to which such person has: (i) sole power to vote or to direct the vote: 2,066,979 (ii) shared power to vote or to direct the vote: 0 (iii) sole power to dispose or to direct the disposition of: 2,066,979 (iv) shared power to dispose or to direct the disposition of: 0 Item 5. Ownership of Five Percent or Less of a Class. Not applicable. Item 6. Ownership of More than Five Percent on Behalf of Another Person. Not applicable. Item 7. Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on By the Parent Holding Company. Not applicable. Item 8. Identification and Classification of Members of the Group. Not applicable. Item 9. Notice of Dissolution of Group. Not applicable. Item 10. Certifications. By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect. By signing below I certify that, to the best of my knowledge and belief, the foreign regulatory scheme applicable to FIL Limited and its various non-U.S. investment management subsidiaries included on this Schedule 13G is substantially comparable to the regulatory scheme applicable to the functionally equivalent U.S. institutions. I also undertake to furnish to the Commission staff, upon request, information that would otherwise be disclosed in a Schedule 13D. Signature After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct. May 6, 2016 Date /s/ Marc R. Bryant Signature Marc R. Bryant Duly authorized under Power of Attorney effective as of September 16, 2015, by and on behalf of FIL Limited and its direct and indirect subsidiaries* * This power of attorney is incorporated herein by reference to Exhibit B to the Schedule 13G filed by FIL Limited on January 11, 2016, accession number: 0000318989-16-000061. Exhibit A Pandanus Partners, L.P. ("Pandanus") owns shares of FIL Limited ("FIL") voting stock. While the percentage of total voting power represented by these shares of FIL voting stock may fluctuate as a result of changes in the total number of shares of FIL voting stock outstanding from time to time, it normally represents more than 25% and less than 50% of the total votes which may be cast by all holders of FIL voting stock. Pandanus Associates, Inc. ("PAI") acts as general partner of Pandanus. Pandanus is owned by trusts for the benefit of members of the family of Edward C. Johnson 3d but disclaims that any such member is a beneficial owner of the securities reported on this Schedule 13G. This filing reflects the securities beneficially owned, or that may be deemed to be beneficially owned, by FIL, certain of its subsidiaries and affiliates, and other companies (collectively, the "FIL Reporters"). This filing does not reflect securities, if any, beneficially owned by certain other companies whose beneficial ownership of securities is disaggregated from that of the FIL Reporters in accordance with Securities and Exchange Commission Release No. 34-39538 (January 12, 1998). RULE 13d-1(k)(1) AGREEMENT The undersigned persons, on May 6, 2016, agree and consent to the joint filing on their behalf of this Schedule 13G in connection with their beneficial ownership of the COMMON STOCK of DIMENSION THERAPEUTICS INC at May 2, 2016. FIL Limited By /s/ Marc R. Bryant Marc R. Bryant Duly authorized under Power of Attorney effective as of September 16, 2015, by and on behalf of FIL Limited and its direct and indirect subsidiaries* Pandanus Partners, L.P. By /s/ Marc R. Bryant Marc R. Bryant Duly authorized under Power of Attorney effective as of September 16, 2015, by Pandanus Associates, Inc. on behalf of Pandanus Partners, L.P.* Pandanus Associates, Inc. By /s/ Marc R. Bryant Marc R. Bryant Duly authorized under Power of Attorney effective as of September 16, 2015, by and on behalf of Pandanus Associates, Inc.* * This power of attorney is incorporated herein by reference to Exhibit B to the Schedule 13G filed by FIL Limited on January 11, 2016, accession number: 0000318989-16-000061.