Human erythrocyte transketolase: no evidence for variants

Using isoelectric focusing of human erythrocyte transketolase, the isoenzyme pattern described recently (Kaczmarek and Nixon, 1983) was reexamined. Seven bands having pI values of 7.4-8.4 were common to the central part of the transketolase isoenzyme pattern in 63 healthy subjects investigated and were definitely reproduced, whereas four additional marginal bands (pI values of 7.2, 7.3, 8.6 and 8.8) were found with varying intensities in part of the samples and could not always be reproduced. We conclude that the method used does not permit the distinction of transketolase variants, that would allow to postulate a genetic polymorphism, based only on variation of the marginal bands of the pattern.