46,XX, inv(6)(p21.1p23) in a pedigree with hereditary haemochromatosis.

Hereditary haemochromatosis (HFE) is a recessive genetic disease of iron overload which has been shown by linkage analysis to reside on the short arm of chromosome 6, close to the major histocompatibility complex (MHC). Positional cloning of the putative HFE locus has been hampered, in part, by the lack of a structural alteration on 6p. In this report, we describe a pedigree with HFE which carries a balanced paracentric inversion of chromosome 6, inv(6)(p21.1p23), a rarely reported chromosomal rearrangement in this region. We have determined the inheritance of the chromosome harbouring the inversion, which segregates as an HFE chromosome. Because the HFE locus has been mapped distal to the HLA-F class I locus at 6p21.3, the breakpoints associated with this chromosomal rearrangement may provide a significant genomic landmark for positional cloning of the HFE gene.