Gene order on the short arm of human chromosome 11: regional assignment of the LDH A gene distal to catalase in two translocations.

Leukemic cells with reciprocal translocations involving 11p13 and 14q13 were obtained from two patients with T-cell acute lymphoblastic leukemia and fused with mouse Ltk- cells. DNA from independent hybrid clones was screened by Southern blot and hybridization to molecular probes for the human catalase and Ha-ras-1 genes. Several clones showed segregation of these two genes, indicating the presence of either the der11 or der14 human chromosomes. When DNA from these hybrid clones was examined for the presence of the human genes for calcitonin and gamma-globin, both genes were found to segregate with the Ha-ras-1 gene and the der14 chromosome indicating that they lie distal to catalase. When the hybrid clones were examined for the presence of human lactate dehydrogenase A (LDH A) activity, only those clones containing the der14 chromosome expressed activity indicating that the LDH A gene is also distal to catalase on the short arm of chromosome 11.