Thanks yes it is. One professor performs the biopsy and writes up results and compares to everyone elses. If anybody in uk has suspected sfn they would normally be seen by him. The other professors interest is sodium channels and genetic neuropathies. He does perform biopsies but not as many as the other. He said it was good to have more fibres! He also said 50% chance to pass on. He said people can have the mutation but doesn't always show symptoms.