A team of researchers from the Ohio State University Comprehensive Cancer Center has discovered a gene mutation, which is believed to have occurred in humans about 11,600 BC.
The study, published in the Orphanet Journal of Rare Diseases, describes the mutation responsible for Imerslund-Gräsbeck syndrome (IGS) in peoples of Arabic, Turkish and Jewish ancestry.
First described over 50 years ago, IGS or selective vitamin B12 malabsorption with proteinuria is a rare disorder characterized by vitamin B12 deficiency, commonly resulting in megaloblastic anemia.
It occurs in children born with two mutated copies of either the amnionless or the cubilin gene. Management of this disorder includes life-long vitamin B12 injections, and with this regimen, the patients stay healthy for decades.
In this study, the researchers examined 20 patients with IGS and their relatives from 16 Muslim and Jewish families.
Their findings show that the mutation was a single ancient event happened in the Middle East around 11,600 BC, making it the second oldest disease mutation in humans.
Only the cystic fibrosis mutation, occurred in Asia some 52,000 years ago, is older.