Mutations of the HFE gene are commonly at fault. In this tutorial, we examine the link between SNPs of the HFE gene and the development of disease. In the course of deciphering whether a SNP is significant, we look to see whether the SNP causes an amino acid change, the nature of this change (e.g., a switch of cysteine to another amino acid may disrupt a disulfide bond), and whether this change takes place in a conserved domain. We also take a look at the amino acid change on a three-dimensional representation of the HFE protein structure.

So... can a switch of a single nucleotide be responsible for a mutant HFE protein that allows iron regulation to go astray?