ITIH1Q0iwate, a null allele of inter-alpha-trypsin inhibitor H1 caused by deletion/frameshift mutation

SummaryThe molecular characterization of the first example of null allele in the inter-alpha-trypsin inhibitor H1 (ITIH1) system,ITIH1*Q0iwate, encountered as apparent inverse homozygosity of ITIH1 phenotypes between mother and child in a paternity case, is described. Single-strand conformation polymorphism analysis and subsequent sequencing showed that deletion of a single nucleotide in the codon for Lys87 results in a frameshift causing a terminator codon downstream of the deletion. This leads to premature termination of ITIH1 protein translation at amino acid 128, resulting in a truncated protein.