Director/PDMR Shareholding

Horizon Discovery™ Group plc

("Horizon" or "the Company")

Director/PDMR Shareholding

Cambridge, UK, 19 June 2014: Horizon (LSE: HZD), the international life science company supplying research tools to organisations engaged in genomics research and the development of personalised medicines, announces that on 19 June 2014 Darrin Disley, Chief Executive Officer, purchased 10,000 shares at 145 pence per share. Following this purchase, Mr Disley's direct beneficial interest in the Company is 682,523 ordinary shares, representing 1.02% of the total issued share capital.

ENDS

Notes to Editors

Contacts:

Horizon Discovery Group plc

Dr Darrin M Disley, Chief Executive Officer

Richard Vellacott, Chief Financial Officer and Senior Vice President, Operations

Tel: +44 (0) 1223 655 580

Consilium Strategic Communications (Financial Media and Investor Relations)

Amber Bielecka / Mary-Jane Elliott / Jessica Hodgson / Matthew Neal

Tel: +44 (0) 20 3709 5701

Email: [email protected]

Zyme Communications (Trade and Regional Media)

Katie Odgaard

Tel: +44 (0)7787 502 947

Email: [email protected]

Panmure Gordon (UK) Limited (NOMAD)

Corporate Finance: Freddy Crossley / Duncan Monteith / Fred Walsh

Broking: Tom Salvesen

Tel: +44 20 7886 2500

About Horizon Discovery Group plc

Horizon is a revenue-generating life science company supplying research tools to organisations engaged in genomics research and the development of personalised medicines. Horizon has a diverse and international customer base approaching 800 organisations, including major pharmaceutical, biotechnology and diagnostic companies as well as leading academic research centers. The Company 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, GENESIS™, 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 has applied GENESIS™ to create over 550 X-MAN™ cell lines, accurately modeling 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 GENASSIST™ CRISPR and rAAV gene editing tools, custom cell line generation services for research and bioproduction applications, quantitative molecular reference standards, contract research and custom screening services, haploid cell lines (through Horizon's partner Haplogen), and custom shRNA development services and off-the-shelf validated shRNA (through Horizon's partner Sirion).

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

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