A television research team called in the help of genealogists in Leicestershire to trace people related to Merrick, who was once exhibited as a circus freak in the 19th Century.
Following a BBC appeal, Pat Selby, from Leicester, contacted her local family history society.
Now the research team will take DNA samples from her and, using the latest genetic techniques, try to diagnose what condition caused his deformities.
Merrick, who was born in Leicester, became famous because of his appearance during the late 19th Century.
His tragic early life and subsequent rescue by the surgeon Sir Frederick Treves formed the basis of director David Lynch's film, The Elephant Man.
Interesting tale
Mrs Selby said: "I'm quite interested in it now - I got a book out of the library.
"I get from reading about him that he was a very nice man."
Peter Cousins, from the Leicestershire and Rutland Family History Society, said: "We are still researching because it is such an interesting story.
"There are some very nice facts coming out."
Mrs Selby is the granddaughter of George and Catherine Potterton who lived in Syston in 1901. Mr Potterton was Merrick's uncle.
DNA proof
It is not known what Merrick suffered from to cause such disfigurements but there are different theories, the strongest being that he suffered from Proteus Syndrome.
The condition was first identified in 1979 and can include partial gigantism and the development of benign growths in an organ or bones.
Many of the conditions that could have caused the disfigurements can now be determined by DNA testing.
The New Zealand-based research team is making a programme for the Discovery Channel and will use Mrs Selby's DNA to try and identify exactly what he suffered from.