Adenosine deaminase (ADA) overproduction associated with congenital hemolytic anemia: case report and molecular analysis
Kanno, H.; Tani, K.; Fujii, H.; Iguchi-Ariga, S.M.; Ariga, H.; Kozaki, T.; Miwa, S.
Japanese Journal of Experimental Medicine 58(1): 1-8
1988
ISSN/ISBN: 0021-5031 PMID: 3164080 Document Number: 320397
We report the fourth case of adenosine deaminase (ADA) overproduction associated with hereditary nonspherocytic hemolytic anemia and the molecular analysis of this anomaly. The proband was a 10-year-old Japanese boy, who had an episode of erythroblastosis fetalis during the perinatal period. The red cell ADA activity showed a 110-fold increase and the red cell ATP level was about 64% of the comparably reticulocyte-rich controls, but the lymphocyte ADA activity was within the normal range. Western blotting of partially purified ADA from red cells revealed an increased amount of enzyme in the patient's red cells. No gene amplification or gene rearrangement was found by Southern blot analysis, and no increase of ADA mRNA in reticulocyte RNA was detected by dot blot analysis using ADA cDNA. We constructed a genomic DNA library and obtained three clones containing the 5'-promoter region of ADA gene. The 2.2 kb ADA promotor DNA fragment of these clones was fused to the chloramphenicol acetyl transferase (CAT) gene, and transfected to human erythroid cell line K562, and assayed for CAT activity. One of the clones, pADOP 2 cat, expressed about 2.6 times higher CAT activity than the normal ADA promotor fused to CAT gene in K562, but such enhancement was not seen in human non-erythroid cell lines; HL 60 and Raji. From these results, it is most likely, though not conclusive, that the 5' promotor fragment of the ADA gene of the patient was responsible for the cell-specific enhancement of protein synthesis.