Assignment of the β-N-acetylhexosaminidase gene (HEXB) to porcine chromosome SSC2q21→q22 by fluorescence in situ hybridization and by analysis of somatic cell and radiation hybrid panels

The enzyme s-N-acetylhexosaminidase B (EC: 3.2.1.52) is a tetramer of two beta-a and two beta-b chains which are derived from the cleavage of a precursor chain, which is a product of the s-N-acetylhexosaminidase B gene (HEXB) (Mahuran, 1999). It catalyses hydrolysis of terminal non-reducing N-acetyl-D-hexosamine residues. Mutations in HEXB gene cause Sandhoff disease in humans (Srivastava and Beuter, 1973). The human HEXB gene stretches over 37 kb and consists of 14 exons (Proia, 1988). Human HEXB has been assigned to chromosome 5q13 (Boedecker et al., 1975). Here we report the localization of the porcine HEXB gene to chromosome 2 confirming homology between the q arms of chromosomes HSA5 and SSC2.