The joint finding of the SCA5 mutation comes over a decade after initial speculation that Lincoln might have suffered from Marfan disease. People with this inherited disorder are often tall and thin and can commonly have slender, tapering fingers. The identification of the Marfan gene at Hopkins (Nature 352, 279-81 ) sparked debate concerning testing of President Lincoln's DNA to determine whether his tall stature could have been caused by that disease.
The present discovery in Lincoln's descendants of the gene that causes a movement disorder called spinocerebellar ataxia type 5 (SCA5), however, appears to offer much stronger evidence that the past president himself might have had SCA5, according to Jeffrey D. Rothstein, M.D., Ph.D., a professor of neurology and neuroscience and vice chairman for research in the Department of Neurology at The Johns Hopkins University School of Medicine. SCAs are neurodegenerative disorders that cause loss of coordination of limbs and eye movements, slurred speech and swallowing difficulties.
"Determining President Lincoln's status relative to SCA5 would be of historical interest and would increase public awareness of ataxia and neurodegenerative disease," Rothstein said. The finding also has wider implications because similar mutations might also be associated with other neurodegenerative diseases, the Hopkins researcher said.
The researchers discovered that SCA5 is caused by a mutation of the -III spectrin gene SPTBN2, which disrupts the ability of certain nerves in the cerebellum to respond
Contact: Eric Vohr
Johns Hopkins Medical Institutions