is the major hexokinase expressed in skeletal muscle. Insulin has been shown to increase transcription of this gene. Lehto et al. (1993) described the isolation of genomic clones for human hexokinase-2. These clones were isolated by screening a human placental genomic library with a rat hexokinase-2 cDNA clone. A genomic clone derived from this screening was used in fluorescence in situ hybridization studies and was found to map to human chromosome 2p13.1. The human HK2 genomic clones were also screened for dinucleotide repeats. Primers were selected to amplify an approximately 224-bp CA-repeat-rich region. This repeat region was highly polymorphic; the level of heterozygosity was 0.63 in Caucasians and 0.51 in Chinese subjects.