Prof Kinnon's research has involved the elucidation of the molecular and cellular defects in inherited immunodeficiency disorders which resulted in the identification of several rare disease causing genes. Research continues on investigating the functions of the protein products of these genes, in both health and disease and in translating the results of this basic research into new and improved strategies for treatment, principally by the development of techniques for the cure of these disorders by somatic gene therapy techniques.

This research resulted in the initiation of phase I clinical trials for the treatment of X-linked severe combined immunodeficiency (SCID), adenosine deaminase (ADA) deficient SCID, X-linked chronic granulomatous disease (CGD) and Wiskott-Aldrich syndrome using gene therapy techniques. 

Prof Kinnon is currently the UCL Academic Lead for the Zayed Centre for Research into Rare Disease in Children, a joint project between UCL, GOSH and the GOSH Children's Charity.