Multicenter Study of Pyruvate Kinase Deficiency in Argentina

Abstract

The red blood cell (RBC) pyruvate kinase deficiency (PKD) is the most common recessive congenital defect of glycolytic enzymes associated with non-spherocytic hemolytic anemia. It is a rare hereditary disorder caused by >300 variants in the PKLR gene. This is a retrospective study of 19 patients from different centers from Argentina with confirmed molecular diagnosis of PKD. Clinical follow-up was carried out from birth in most cases. Five consanguineous patients from “gypsy” community, were homozygous for the “PK-Gypsy deletion” (PK-Gd). During the neonatal period they developed anemia with icterus. Transfusion exchange was required in 60%, light therapy in 80%, and RBC transfusion in 80%. During the follow-up iron overload was detected in the 100%, cholecystectomy was indicated in 40%, and splenectomy in 60%. Thirteen cases had 2 missense variants (MS), being the Mediterranean variant (p.Arg486Trp) the more frequent detected (26%).Only 1 patient had a missense-splicing mutation combination. During the neonatal period, 86% had anemia and icterus. Light therapy was required in 78%, transfusion exchange in 21% and RBC transfusion in 64%. During the follow-up iron overload was detected in 57% and splenectomy was indicated in 43%. Transfusions (pre-splenectomy and post-splenectomy) were more required in PK-Gd cases as compared with patients with point mutations (100%/60% vs 71%/29% respectively). Our data indicates a high clinical-therapeutic-molecular heterogeneity in PKD patients with the PK-Gd group presenting the most severe cases.