 It has been further suggested that mutations on CUBN were restricted to exon 1-28 which encoded amnionless binding domains (EGF) and IF-Cbl binding region of cubilin, while AMN mutations primarily clustered in intron 8-11 and transmembrane domain in exon 10.Some interesting aspects of particular mutations were also elucidated by the researchers, for example, "CUBN" mutation c.3890C>T; p.Pro1297Leu, was considered to be a Finnish founder mutation presenting mostly in homozygous status, while an "AMN" mutation c.208-2A>G, which was thought to account for 15% IGS cases around the world, was postulated as an ancient founder mutation that can trace back to approximately 13,600 years ago.Vitamin B12, is an essential water-soluble vitamin found in animal products (such as liver, meat, fish, and dairy products).