[A case of serum cholinesterase anenzymia]

A report is given on a 66-year-old man suffering from serum cholinesterase anenzymia. The following tests were performed to characterize the genetic pseudo-cholinesterase variants: plasma cholinesterase activity using benzoyldicholine as substrate (according to Kalow) and dibucaine and sodium fluoride as inhibiting substances. In addition, polyacrylamide density gradient gel electrophoresis followed by esterase staining technique (Mascall) was used for the electrophoretic separation of cholinesterase isoenzymes. Similarly, the only daughter's and the granddaughter's sera were analyzed. Determination of activity and inhibitor numbers indicated that the propositus had the homozygote "silent gene" genotype (A = 2, DN = 0, FN = 0). The granddaughter showed an isoenzyme constellation within normal ranges (A = 128, DN = 80, FN = 58); for the daughter apparently normal values were also found for activity and inhibitor numbers (A = 73, DN = 82, FN = 58). Figure 1 shows the results of electrophoretic separation from the sera tested and Fig. 2 results obtained by densitometric assessment. Electrophoretic separation and the zymogram obtained from the propositus' serum show only sample peak and albumin fractions. In contrast, the granddaughter's serum turned out to be absolutely normal. In the daughter's sample, however, three cholinesterase components normally found in serum were missing, as also shown by densitometry. Despite apparently normal activity and rather insignificant inhibitor numbers, gradient gel electrophoresis clearly revealed her to be a heterozygote carrier of the silent gene Es variant. As our data are in accordance with results obtained by other investigators, this observation cannot be regarded as exceptional.(ABSTRACT TRUNCATED AT 250 WORDS)