(CNN) -- Was President Abraham Lincoln dying of a rare genetic disease when an assassin killed him in 1865?
A California doctor believes so -- and he hoped to prove his theory by testing the 16th president's DNA.
Dr. John Sotos asked a small Philadelphia museum for blood-stained threads from a scrap of the pillow that cradled Lincoln's head as he lay dying.
On Monday night, the board of the Grand Army of the Republic Museum and Library denied his request but left the door open for a possible DNA test that could shed light on Lincoln's last days.
The museum plans to convene a forum of Lincoln scholars and forensic pathologists to decide how to proceed.
"We want complete control over this," said Eric Schmincke, the board's president. "We don't want to take the chance of losing the artifact."
I've updated this piece with a longer article on Lincoln's DNA.