The human tissue transglutaminase gene maps on chromosome 20q12 by in situ fluorescence hybridization.

A cDNA encoding for the human tissue transglutaminase gene has been used to identify the chromosomal localization of the corresponding structural gene. The precise chromosomal and subregional localizations have been established by using in situ fluorescence mapping with a recombinant lambda-Zap phage containing the full cDNA coding sequence. The study showed that the human tissue transglutaminase gene is localized on chromosome 20 and, more precisely, within the band 20q12. To date, this is the third member of the transglutaminase gene family to be mapped. Human factor XIIIa (plasma transglutaminase), human keratinocyte transglutaminase (type I), and human tissue transglutaminase (type II) genes, although codifying for homologous enzymes, are localized on three different chromosomes.