Identification of a mouse homolog for the human hereditary haemochromatosis candidate gene.

Recently, a novel human major histocompatibility complex (MHC) class I-like gene (HLA-H) was reported as a candidate gene for human hereditary haemochromatosis, a recessive disease of iron metabolism with a remarkably high incidence in northern Europeans. Independently we have isolated this gene in the course of a search for new human MHC class I-related genes and named it MR2. Here we report a mouse homolog of this human gene. The mouse MR2 gene is similar to the human counterpart with an overall predicted amino acid sequence similarity of approximately 66% and it is expressed in various tissues as in human. The extra eight amino acid residues between the alpha1 and the alpha2 domains in the mouse molecule compared to the human counterpart can be explained by the creation of the coding sequence from the intron. While the human gene is located at the site telomeric to the MHC region on human chromosome 6, our study indicated the translocation of the mouse homolog from the site telomeric to the MHC on mouse chromosome 17 to chromosome 13 along with other genes. This mouse gene should be important in clarifying a possible role in iron metabolism.