Charles Byrne was the tallest Irishman who ever lived. He made his money as a freak in a circus and he grew to 7 feet seven inches tall at his height.

Now an article in today’s New England Journal of Medicine has finally identified the mutated gene that caused his condition-- as well as modern relatives who have the disease too.

When he died in 1783 a surgeon named John Hunter bought his body and  boiled the flesh off with acid and exhibited the skeleton in London.

Now through modern day forensics a relative of Byrne, who also has the same condition, has been traced and the mystery of why Charles Byrne grew so tall has been solved.

The Journal of Medicine reported that researchers in Britain and Germany extracted DNA from Byrne’s teeth and identified a rare and mysterious gene mutation that was discovered only in 2006
Researchers have now found the  same mutation in four families from Northern Ireland, close by where Charles Byrne was born.

The group was  led by Dr. Marta Korbonits, professor of endocrinology and metabolism at Barts and the London School of Medicine and Dentistry.

They proved tht Byrne had a very rare pituitary tumor that led to disfigurement — “patients develop a bulging forehead and large jaw, hands and feet — and chronic severe headaches.” the Journal reports.

Dr. Shlomo Melmed, a pituitary tumor researcher at Cedars-Sinai Medical Center in Los Angeles, says such tumors are very important to study. He explained that the tumor cells undergo premature aging and do not kill like other  tumors.

The investigators discovered  that the giant and the four contemporary Irish families had the same  ancestor who lived about 1,500 years ago -- and many have the same tumor.

One of them is Brendan Holland, a 58-year-old Irishman who experienced the same massive growth surge.

“I kept growing and growing,” Holland said, eventually stopping at 6 feet 9 inches. His pituitary tumor was discovered and treated and he was able to live a normal life.

A study of his DNA and the 18th century giant’s DNA revealed they were related.

He said he was touched  by knowing what happened to his predecessor and how he must have suffered as  subject of  massive curiosity and freak shows.

* Originally published in 2011.