Non-spherocytic hemolytic anemia caused by erythrocyte pyruvate kinase defiiency: the analysis of genetic defects in pediatric patients, living in Russian Federation

The article presents retrospective data analysis of a cohort of patients with PKD (n = 41 patients, aged 4 months – 26,5 years, median of age – 5 years 1 month) who were examined at the Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology for unspecifid hereditary hemolytic anemia during the period 2013–2020. The study was approved by the Independent Ethics Committee of the Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology. In all patients, the diagnosis was confimed by Next Generation sequencing (NGS). The homozygous mutations in the PKLR gene were found in 10 patients (24.39%), compound heterozygous mutations in 31 patients (75.61%), 77.78% of them were missense mutations. Gender distribution (male:female) was 1:1.73. At least once transfusion of erythrocyte suspension was required to 40 (97.56%) patients. The minimum age at the time of the debut of transfusion dependence was the fist day of life, the maximum was 4 years. Exchange blood transfusion was performed in 13 children, severe normocytic hyperregenerative anemia with transfusion of red blood cells in the fist days of life was noted in 12 children, at the 1st month of life – in 9 children, at the 2nd month of life – in 8 children, at the 3rd month – in 6 children, at the 5th month – in 2 children, at the 1st year – in 1 child, and 2 children underwent single transfusions on the background of infectious episodes at 3 and 4 years respectively. Splenectomy due to high transfusion dependence was performed in 10 patients: transfusion independence was achieved in 5 patients, in 5 – an increase in the interval between blood transfusions. Median of surgical intervention (9 patients): 7 years 4 months, minimum age – 1 year 4 months, maximum – 14 years 4 months. In total, 36 genotypes were described in 41 patients, among them were: c.1529G>A in 3 patients, c.1137_1139del / c.1456C>T – in 2 patients, c.1079G>A/c.1529G>A in 2 patients, c.1130T>C/c.1456C>T in 2 patients, other genotypes occurred once. Two mutations were the most frequent: c.1456C>T (16.67%) and c.1529G>A (16.67%). 19 (46,34%) of patients had previously not described mutations.