Charles Darwin suffered debilitating, relapsing illness with a bewildering array of symptoms. Diagnoses for this illness date back to Darwin’s lifetime and have continued until this present day; these diagnoses reflect concepts fashionable when they were proposed.

Impure air in Darwin’s day was accompanied with diagnoses such as ‘atypical gout’ and ‘aggravated dyspepsia’. In the mid 20^th century psychological or psychogenic causes were proposed, along with the concept of intrauterine (foetal) traumas, followed by infections, allergy, autoimmune disease, heavy metal poisoning and irritable bowel. The latest is post-traumatic stress disorder. Darwin certainly had symptoms of some of the proposed disorders– he had atopic dermatitis, he had panic attacks, he had chronic fatigue and fibromyalgia and symptoms seen in cyclic vomiting. None of these diagnoses account for all of Darwin’s symptoms. Diagnosticians have not considered his unrelenting seasickness as part of his intrinsic illness and none have considered his very relevant family history.

Adult onset mitochondrial disease due to a maternally inherited pathological mtDNA mutation accounts for all of Darwin’s symptoms, accounts for the illnesses of his siblings and the strange illnesses that affected his Wedgwood maternal forebears. This mitochondrial diagnosis has still to withstand the test of time.