Aug. 20: The human genome is riddled with dead genes, fossils of a sort, dating back hundreds of thousands of years — the genome’s equivalent of an attic full of useless junk.
Some of those genes, surprised geneticists reported on Thursday, can rise from the dead to cause one of the most common forms of muscular dystrophy. This is the first time, geneticists say, that they have seen a dead gene come back to life and cause a disease.
“If we were thinking of a collection of the genome’s greatest hits, this would go on the list,” said Dr Francis Collins, a human geneticist and director of the National Institutes of Health.
The disease, facioscapulohumeral muscular dystrophy, known as FSHD, is one of the most common forms of muscular dystrophy. It was known to be inherited in a simple pattern with its cause poorly understood, until now.
The culprit gene is part of what has been called junk DNA, whose function is largely unknown.
The dead genes had seemed permanently disabled. But, said Dr Collins, “the first law of the genome is that anything that can go wrong, will.”
Dr David Housman, a geneticist at MIT, said scientists will now be looking for other diseases with similar causes.