Painful Channelopathies Study

To understand the pathophysiological basis of heritable pain syndromes. This will consist of a number of components: * Determine the genetic basis for heritable pain syndromes. * Investigate the pain symptoms, psychological co-morbidity and quality of life in patients with heritable pain syndromes. * Use quantitative sensory testing to investigate abnormalities in sensory processing. * Use imaging modalities to investigate the neural correlates of pain perception in heritable channelopathies. * In select patients to perform skin biopsy to determine if there has been any damage to C-fibres. * To perform skin biopsy in order to culture fibroblasts and neural crest stem cells for future studies into the molecular basis of altered pain perception. * To use neurophysiological tests, the axon reflex, and conditioning challenges to determine how peripheral nerves, in heritable channelopathies and unusual pain syndromes, have been altered. * Microneurographic recordings for directly detecting the function of pain fibres in peripheral nerves. Knowledge gained from the study will be used to aid the further development of genetic testing and specific pain questionnaires for the diagnosis of heritable pain syndromes secondary to channelopathies. * Ultimately better knowledge of underlying pathophysiology in these heritable pain conditions may inform the development of novel treatments.