EDS, or Ehlers-Danlos syndrome, is a genetic collagen disorder frequently involving fatigue, joint pain, exceptional flexibility, and numerous other symptoms. Once thought rare, it may affect as many as 1 in 5000 people, perhaps accounting for at least a small percentage of those diagnosed with Chronic Fatigue Syndrome or Fibromyalgia. It is usually a hidden disability until later in life, and as such, sufferers are prey to very considerable discrimination and contempt, often as much from their own families as society.

Paganini is believed to have suffered from this illness, and possibly the Canadian pianist Glenn Gould, whose appearance and so-called eccentricities are common for this illness.