Total Voting Rights

Total Voting Rights

Horizon Discovery Group plc, announces that the Company's issued share capital at the date of this announcement consists of 94,087,603 ordinary shares of 1p each ("Ordinary Shares"). The Company does not hold any Ordinary Shares in Treasury.

Therefore the total number of Ordinary Shares in the Company with voting rights is 94,087,603.

This figure of 94,087,603 ordinary shares may be used by shareholders in the Company as the denominator for the calculations by which they will determine if they are required to notify their interest in, or a change in their interest in, the share capital of the Company under the FCA's Disclosure and Transparency Rules.

ENDS

For further information from Horizon Discovery Group plc, please contact:

Horizon Discovery Group plc

Dr. Darrin Disley CEO / Richard Vellacott CFO

Tel: +44 (0) 1223 655580

Consilium Strategic Communications (Financial Media and Investor Relations)

Amber Fennell / Jessica Hodgson / Matthew Neal / Laura Thornton

Tel: +44 (0) 20 3709 5701

Email: [email protected]

Panmure Gordon & Co. (NOMAD)

Corporate Finance: Freddy Crossley / Fabien Holler / Duncan Monteith

Corporate Broking: Tom Salvesen

Tel: +44 20 7886 2500

Notes for Editors

About Horizon Discovery Group plc www.horizondiscovery.com/

Horizon is a revenue-generating life science group supplying research tools to organizations engaged in translational genomics research and the development of personalized medicines. Horizon has a diverse and international customer base of over 1,200 organizations across more than 50 countries, including major pharmaceutical, biotechnology and diagnostic companies as well as leading academic research centers. The Group supplies its products and services into multiple markets, estimated to total in excess of £29 billion by 2015.

Horizon's core capabilities are built around its proprietary translational genomics platform, a high-precision and flexible suite of gene editing tools able to alter almost any endogenous gene sequence of human or mammalian cell-lines. Horizon offers over 20,000 catalogue products, almost all of which are based on the application of gene editing to generate cell lines that accurately model the disease-causing mutations found in genetically based diseases. These 'patients-in-a-test-tube' are being used by customers to identify the effect of individual or compound genetic mutations on drug activity, patient responsiveness, and resistance, which may lead to the successful prediction of which patient sub-groups will respond to currently available and future drug treatments.

In addition, Horizon provides custom cell line and in vivo model generation services for research and bioproduction applications, quantitative molecular reference standards, in vivo disease models, and contract research and custom screening services.

Horizon is headquartered in Cambridge, UK, and is listed on the London Stock Exchange's AIM market under the ticker "HZD", for further information please visit: www.horizondiscovery.com.