HEREDITARY-DEFICIENCY OF LACTATE-DEHYDROGENASE H-SUBUNIT

We report herein the fifth family of hereditary deficiency of lactate dehydrogenase (LDH) H-subunit with an autosomal recessive inheritance including two cases of complete deficiency. Their LDH activities were low both in the serum and in the red blood cells (RBC). Electrophoreti c analysis revealed that the patients with the complete deficiency had only the LDH(5) isozyme. The complete deficiency was associated with marked elevation of fructose-1,6-diphosphate (FDP) and dihydroxyaceton ephosphate (DHAP) and a less marked rise in glyceraldehyde-3-phosphate (GA3P) among glycolytic intermediates in the RBC. Furthermore, hemoly sis was observed in the present cases, but this finding was not includ ed in the other reports.