Prof. Tang started the first metabolic clinic in Hong Kong to take care of patients with various inborn errors of metabolism, which are rare genetic diseases in children, more than 20 years ago. His research team has contributed to the discovery of the disease gene causing Primary Carnitine Deficiency (named by Prof. Tang as 卡尼丁缺乏症 in Chinese which has become the standard Chinese medical term now). His discovery has facilitated the molecular diagnosis of this disease and more than 1,000 patients of this rare disease have been diagnosed and treated all over Mainland China and Asia.

Prof. Tang has held various professional and academic positions, for example, serving on the Advisory Committee of Genetic Pathology in the Royal College of Pathologists of Australasia (RCPA), being an editor of RCPA Catalogue of Genetic Tests and Laboratories and Pathology Manual and an examiner in the Fellowship examination for RCPA. Prof. Tang is a member of the Grant Review Board of Health and Medical Research Fund of the Hong Kong SAR Government. He is regularly invited to review grant proposals for Research Grant Council (HK) and various grant bodies in Mainland China, United Kingdom, Singapore, South Africa, Poland etc. He supervised more than 20 postgraduate students at both master and doctorial levels. Prof. Tang has been on the examination boards of graduate schools in many universities to examine PhD students, for example, the University of Hong Kong, The Hong Kong University of Science and Technology, Peking University, University of Sydney etc. He reviewed more than 50 journal manuscripts for various renowned Journals in the past 3 years.