Radiologists in London say X-ray and CT scans of Merrick's remains suggest that he did not have neurofibromatosis, the disfiguring condition sometimes called Elephant Man disease.
According to the experts from the Royal London Hospital he suffered from a much rarer disease called Proteus syndrome.
Neurofibromatosis causes uncontrolled growth of nerve cells, giving rise to unsightly tumours.
There have been fewer than 100 recorded cases of Proteus syndrome, which involves the abnormal growth of bone and soft tissue. Both conditions are thought to be genetic.
Merrick, who was portrayed by John Hurt in the hit film The Elephant Man, died in 1890 at the London Hospital, where he lived for four years after being rescued from a life as a circus freak by the doctor Frederick Treves. His remains were kept at the hospital, now renamed the Royal London.
The magazine New Scientist reported: "Sharma says that his skeleton shows the tell-tale signs of Proteus syndrome and lacks the characteristics that would be expected of someone with neurofibromatosis. Merrick's skeleton is studded with bony outgrowths, predominantly on the right-hand side. His ring finger and femur are both enlarged, and his skull has a circumference of 91cm, compared to the 60cm typical for a man of his height."
Merrick's spine was also not sharply curved, as would be expected in a case of neurofibromatosis, and his ribs lacked notches common in the condition.
Radiologist Anita Sharma and her colleagues gave their diagnosis at a meeting of the Radiological Society of North America in Chicago.Reuse content