Mutant gene found in Irish giant

A RACE of giants may have sprung from a mutant gene that first emerged around 1,500 years ago and which causes uncontrolled body growth, scientists believe.

The ‘gigantism gene’ was identified in the DNA of an 18th century man known as the “Irish giant” who stood almost eight feet tall.

Copies of the same mutation have been found in living patients suffering from gigantism and other symptoms of over-growth.

Scientists writing in the New England Journal of Medicine said they suspect all inherited the gene from the same common ancestor who lived up to 66 generations ago. Around 200 to 300 people may be carrying the same mutation today.

The Irish giant was Charles Byrne — also known by his stage name O’Brien — born in Littlebridge, Co Derry, in 1761.

In the 1780s he found fame exhibiting himself as a curiosity or ‘freak’ in London. Despite claims he towered more than eight feet tall, skeletal evidence shows his height to have been just over seven feet seven inches.

Celebrity life eventually got the better of Byrne, who took to drink. He died at his home in Charing Cross, London, aged 22. His body was acquired by the 18th century surgeon John Hunter, and his skeleton remains at the Hunterian Museum at the London headquarters of the Royal College of Surgeons.

However, in recent years a campaign has gathered pace to release the skeleton from the museum so Byrne can have his dying wish to be buried at sea. He made the request to prevent the fate that eventually befell him — that of being a specimen to be put on display.

British and German scientists conducting the new research extracted DNA from two of the giant’s teeth. They discovered a mutant version of the aryl hydrocarbon-interacting protein gene which matched those found in living patients from four Northern Irish families.

The gene variant triggers tumour growth in the pituitary gland at the base of the brain. Among its many functions, the gland releases hormones that regulate growth. Pituitary tumours can cause tissue to grow abnormally, which may lead to gigantism — as suffered by Byrne — or acromegaly.

Symptoms of acromegaly include thickened skin and.

By analysing the DNA, the scientists calculated that all the carriers of the mutant AIP gene had inherited the genetic fault from a common ancestor.

Professor Marta Korbonits, from Barts and the London School of Medicine and Dentistry, who led the research, said:

“The most important clinical aspect of our study is it is now possible to trace down carriers of this gene in time and treat patients before they grow to be a giant.”