Hereditary regulatory enzymopathies are considered, molecular-genetic mechanism of which involved a mutation of a structural gene in the locus, coding the much less than regular much greater than amino acid sequence in the allosteric site of regulatory enzyme or the site of the enzyme polypeptide chain, which is responsible for allosteric conformational transition. Dissimilar manifestations of regulatory and classical enzymopathies are discussed. Estimation of kinetic patterns might be very useful in diagnosis of regulatory enzymopathies as shown during study of some molecular pathologies, which occurred, for example, due to molecular pathology of phosphofructokinase and phosphoribosyl pyrophosphate synthetase. Impairment of allosteric regulation of L-threonine-L-serine dehydratase is considered as a model of regulatory enzymopathy, found in spontaneous hepatomas of highly carcinogenous CBA mice strain. Treatment of regulatory enzymopathies is considered depending on the effect of well known chemotherapeutic drugs (mainly, acetyl salicylic acid) on allosteric functions of regulatory enzymes acetyl-CoA-carboxylase and fructose-1,6-bisphosphatase from animal liver tissue.