Family Study of a Pyruvate Kinase (PK) Variant

Abstract

A case of pyruvate kinase variant and its family study are reported. The patient, 26 year-old female, was admitted to our hospital in January 1980 because of anemia and jaundice. On physical examination, anemia and jaundice in the conjunctiva and hepatomegaly were detected. During her hospitalization, there were no symptoms except general fatigue and slight dizziness. Laboratory data revealed macrocytic anemia, slight hyperbilirubinemia with predominant elevation of indirect bilirubin, elevated serum LDH level, reticulocytosis and positive hemosiderin in urine. The enzymatic analysis of red blood cell showed low PK activity (14.9%). In the family study of PK activities in her father, mother, elder brother and younger brother were 47.6%, 102.3%, 64.1%, and 21.3%, respectively. From these data it was suggested that her father and elder brother were heterozygotes, and her mother was a heterozygote of the PK variant which was probably different in character from that of her fater. The patient and her younger brother were homozygotes. Although the site of hemolysis in PK variant has been proposed to be mainly in the spleen, the possibility of intravascular hemolysis could not boe denied.