<prompt> The following enzyme activity is measured in Beriberi:DecarboxylaseDeaminaseTransketolaseTransaminase  <response>: In thiamine deficiency transketolase activity in erythrocytes is decreased. Measures of RBC transketolase is a reliable diagnostic test for thiamine deficiency. Beriberi is caused by thiamine deficiency. Ref: Clinical Laboratory Medicine, 2nd Ed, Page 322 