Molecular alterations in congenital erythrocyte pyruvate kinase deficiencies

The molecular heterogeneity of congenital pyruvate kinase deficiencies becomes apparent from the results of immunological studies. In one case, a quantitative defect is plausible; in the second case, the most likely hypothesis is a molecular alteration of the binding site for the activator, with preservation of the antigenic specificity; in the third case an abnormal protein, extremely unstable and devoid of antigenic reactivity, carries catalytic activity. In no case can any cross-reacting material be detected.