MAPPING OF HUMAN INTER-ALPHA-TRYPSIN INHIBITOR FAMILY HEAVY CHAIN-RELATED PROTEIN GENE (ITIHL1) TO HUMAN-CHROMOSOME 3P21-]P14

Inter-alpha-trypsin inhibitor family heavy chain-related protein (IHRP ) is a novel glycoprotein isolated from human plasma. The cDNA encodin g IHRP has recently been cloned from human liver cDNA Libraries. We re port the mapping of this gene (ITIHL1) by fluorescence in situ hybridi zation using a 2.5-kb cDNA fragment as a probe. ITIHL1 was localized t o chromosome region 3p21 --> p14 where the genes of heavy chain 1 and 3 of inter-alpha-trypsin inhibitor are located. This result, together with significant homology between the nucleotide sequences of ITIHL1 a nd the heavy chain genes, supports ITIHL1 as being a member of an evol utionary related gene family of ITI heavy chains. Northern blot analys is indicated that IHRP was predominantly synthesized in liver. From So uthern blot analysis, it was tentatively concluded that ITIHL1 is a si ngle copy gene.