RESUMO
Pyruvate kinase (PK), encoded by the PKLR gene, is a key player in glycolysis controlling the integrity of erythrocytes. Due to Plasmodium selection, mutations for PK deficiency, which leads to hemolytic anemia, are associated with resistance to malaria in sub-Saharan Africa and with susceptibility to intracellular pathogens in experimental models. In this case-control study, we enrolled 4,555 individuals and investigated whether PKLR single nucleotide polymorphisms (SNPs) putatively selected for malaria resistance are associated with susceptibility to leprosy across Brazil (Manaus-North; Salvador-Northeast; Rondonópolis-Midwest and Rio de Janeiro-Southeast) and with tuberculosis in Mozambique. Haplotype T/G/G (rs1052176/rs4971072/rs11264359) was associated with leprosy susceptibility in Rio de Janeiro (OR = 2.46, p = 0.00001) and Salvador (OR = 1.57, p = 0.04), and with tuberculosis in Mozambique (OR = 1.52, p = 0.07). This haplotype downregulates PKLR expression in nerve and skin, accordingly to GTEx, and might subtly modulate ferritin and haptoglobin levels in serum. Furthermore, we observed genetic signatures of positive selection in the HCN3 gene (xpEHH>2 -recent selection) in Europe but not in Africa, involving 6 SNPs which are PKLR/HCN3 eQTLs. However, this evidence was not corroborated by the other tests (FST, Tajima's D and iHS). Altogether, we provide evidence that a common PKLR locus in Africans contribute to mycobacterial susceptibility in African descent populations and also highlight, for first, PKLR as a susceptibility gene for leprosy and TB.
Assuntos
Malária/genética , Polimorfismo de Nucleotídeo Único , Piruvato Quinase/genética , Adulto , Brasil , Estudos de Casos e Controles , Feminino , Frequência do Gene , Predisposição Genética para Doença , Haplótipos , Humanos , Desequilíbrio de Ligação , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Moçambique , Piruvato Quinase/deficiência , Adulto JovemRESUMO
BACKGROUND: Pyruvate kinase deficiency (PKD) is a rare recessive congenital hemolytic anemia caused by mutations in the PKLR gene. The disease shows a marked variability in clinical expression. We studied the molecular features of nine unrelated Argentinian patients with congenital hemolytic anemia associated with erythrocyte pyruvate kinase deficiency. DESIGN AND METHODS: Routine hematologic investigations were performed to rule out other causes of chronic hemolytic anemia. Sanger sequencing and in-sílico analysis were carried out to identify and characterize the genetics variants. RESULTS: Six different novel missense variants were detected among the 18 studied alleles: c.661 G > C (Asp221His), c.956 G > T (Gly319Val), c.1595 G > C (Arg532Pro), c.347 G > A (Arg116Gln), c.1232 G > T (Gly411Val), c.1021G > A (Gly341Ser). Structural implications of amino-acid substitutions were correlated with the clinical phenotypes seen in the probands. CONCLUSIONS: This is the first comprehensive report on molecular characterization of pyruvate kinase deficiency in Argentina and the second from South America that would contribute to our knowledge on the distribution and frequency of PKLR variants in our population but also offer new insights into the interpretation of the effect of PKLR variants and phenotype.
Assuntos
Alelos , Anemia Hemolítica Congênita não Esferocítica/genética , Mutação de Sentido Incorreto , Piruvato Quinase/deficiência , Erros Inatos do Metabolismo dos Piruvatos/genética , Adolescente , Adulto , Substituição de Aminoácidos , Argentina , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Piruvato Quinase/genéticaRESUMO
Abstract Background: Pyruvate kinase deficiency is a hereditary disease that affects the glycolytic pathway of the red blood cell, causing nonspherocytic hemolytic anemia. The disease is transmitted as an autosomal recessive trait and shows a marked variability in clinical expression. This study reports on the molecular characterization of ten Brazilian pyruvate kinase-deficient patients and the genotype-phenotype correlations. Method: Sanger sequencing and in silico analysis were carried out to identify and characterize the genetic mutations. A non-affected group of Brazilian individuals were also screened for the most commonly reported variants (c.1456C>T and c.1529G>A). Results: Ten different variants were identified in the PKLR gene, of which three are reported here for the first time: p.Leu61Gln, p.Ala137Val and p.Ala428Thr. All the three missense variants involve conserved amino acids, providing a rationale for the observed enzyme deficiency. The allelic frequency of c.1456C>T was 0.1% and the 1529G>A variant was not found. Conclusion: This is the first comprehensive report on molecular characterization of pyruvate kinase deficiency from South America. The results allowed us to correlate the severity of the clinical phenotype with the identified variants.
Assuntos
Humanos , Masculino , Feminino , Piruvato Quinase/deficiência , Eritrócitos , Anemia Hemolítica , MutaçãoRESUMO
We identified the pyruvate kinase liver/red cell enzyme gene mutation of 8 children previously diagnosed with pyruvate kinase deficiency who were living in a remote town in the western United States. Six were found to be homozygous for the mutation 1529G-A (510 Arg-Gln). Two previously thought to have pyruvate kinase deficiency did not, because they were heterozygous.
Assuntos
Mutação , Piruvato Quinase/deficiência , Piruvato Quinase/genética , Anemia Hemolítica Congênita/etiologia , Colelitíase/etiologia , Triagem de Portadores Genéticos , Perda Auditiva/etiologia , Homozigoto , Humanos , Hiperbilirrubinemia/etiologia , Icterícia/etiologia , População Rural , Estados UnidosRESUMO
Pyruvate kinase (PK) deficiency is a rare red cell glycolytic enzymopathy. The purpose of the present investigation was to offer prenatal diagnosis for PK deficiency to a couple who had a previous child with severe enzyme deficiency and congenital non-spherocytic hemolytic anemia. PK deficiency was identified in the family by assaying the enzyme activity in red cells. Chorionic villus sampling was performed in an 11-week gestation and the mutation was located in exon 10 of the PKLR gene characterized by polymerase chain reaction and using restriction endonuclease digestion with the MspI enzyme, which was confirmed by DNA sequencing on the ABI 310 DNA sequencer. Both the parents were heterozygous for the 1436G-->A [479 Arg-->His] mutation in exon 10 and the proband was homozygous for this mutation. The fetus was also heterozygous for this mutation and the pregnancy was continued. Prenatal diagnosis allowed the parents with a severely affected child with PK deficiency to have the reproductive choice of having the fetus tested in a subsequent pregnancy.
Assuntos
Anemia Hemolítica Congênita não Esferocítica/diagnóstico , Mutação , Diagnóstico Pré-Natal/métodos , Piruvato Quinase/deficiência , Piruvato Quinase/genética , Anemia Hemolítica/genética , Anemia Hemolítica Congênita não Esferocítica/genética , Análise Mutacional de DNA , Enzimas de Restrição do DNA/metabolismo , Éxons , Feminino , Homozigoto , Humanos , Índia , Masculino , Gravidez , Primeiro Trimestre da GravidezRESUMO
Pyruvate kinase (PK) deficiency is asymptomatic in heterozygotes, but it can lead in homozygous neonates to a severe neonatal hemolysis, sometimes life-threatening. We report five cases, with a 1- to 17-month delayed diagnosis, highlighting the need to measure PK activity in neonates and parents in case of an hemolysis at birth.
Assuntos
Erros Inatos do Metabolismo/diagnóstico , Piruvato Quinase/deficiência , Anemia/etiologia , Feminino , Testes Genéticos/métodos , Humanos , Lactente , Recém-Nascido , Masculino , Erros Inatos do Metabolismo/complicações , Erros Inatos do Metabolismo/genética , Erros Inatos do Metabolismo/terapia , Mutação/genética , Triagem Neonatal/métodos , Polimorfismo de Fragmento de Restrição , Resultado do TratamentoRESUMO
Pyruvate kinase (PK) deficiency is a rare red cell glycolytic enzymopathy. The purpose of the present investigation was to offer prenatal diagnosis for PK deficiency to a couple who had a previous child with severe enzyme deficiency and congenital non-spherocytic hemolytic anemia. PK deficiency was identified in the family by assaying the enzyme activity in red cells. Chorionic villus sampling was performed in an 11-week gestation and the mutation was located in exon 10 of the PKLR gene characterized by polymerase chain reaction and using restriction endonuclease digestion with the MspI enzyme, which was confirmed by DNA sequencing on the ABI 310 DNA sequencer. Both the parents were heterozygous for the 1436G-->A [479 Arg-->His] mutation in exon 10 and the proband was homozygous for this mutation. The fetus was also heterozygous for this mutation and the pregnancy was continued. Prenatal diagnosis allowed the parents with a severely affected child with PK deficiency to have the reproductive choice of having the fetus tested in a subsequent pregnancy.
Assuntos
Humanos , Masculino , Feminino , Gravidez , Anemia Hemolítica Congênita não Esferocítica/diagnóstico , Diagnóstico Pré-Natal/métodos , Mutação , Piruvato Quinase/deficiência , Piruvato Quinase/genética , Anemia Hemolítica Congênita não Esferocítica/genética , Anemia Hemolítica/genética , Análise Mutacional de DNA , Enzimas de Restrição do DNA/metabolismo , Homozigoto , Primeiro Trimestre da Gravidez , Éxons , ÍndiaRESUMO
Pyruvate kinase (PK) deficiency is the most common cause of hereditary nonspherocytic hemolytic anemia. The prevalence of this deficiency is unknown, though some estimates have been made based on the frequency of low red cell PK activity in the population. An additional 20 patients with hereditary nonspherocytic hemolytic anemia caused by PK deficiency have been genotyped. One previously unreported mutation 1153C-->T (R385W) was encountered. The relative frequency of PK mutations in patients with hemolytic anemia caused by PK deficiency was calculated from the 18 white patients reported here and from 102 patients previously reported in the literature. DNA samples from 3785 subjects from different ethnic groups have been screened for the 4 more frequently encountered mutations-c.1456 C-->T(1456T), c.1468 C-->T(1468T), c.1484 C-->T(1484T), and c.1529 G6A (1529A)-by allele-specific oligonucleotide hybridization. Among white patients the frequency of the 1456T mutation was 3.50 x 10(-3); that of the 1529A mutation was 2.03 x 10(-3). Among African Americans the frequency of the 1456T mutation was 3.90 x 10(-3) The only mutation found in the limited number of Asians tested was 1468T at a frequency of 7.94 x 10(-3). Based on the gene frequency of the 1529A mutation in the white population and on its relative abundance in patients with hemolytic anemia caused by PK deficiency, the prevalence of PK deficiency is estimated at 51 cases per million white population. This number would be increased by inbreeding and decreased by failure of patients with PK deficiency to survive.
Assuntos
Anemia Hemolítica/genética , Frequência do Gene , Mutação , Piruvato Quinase/deficiência , Piruvato Quinase/genética , População Branca/genética , Substituição de Aminoácidos , Árabes , Ásia/etnologia , Brasil/etnologia , Eritrócitos/enzimologia , Etnicidade/genética , Europa (Continente)/etnologia , Triagem de Portadores Genéticos , Genótipo , Humanos , Estados UnidosRESUMO
Se describe el segundo caso hallado en Costa Rica de anemia hemolítica crónica no esferocítica (AHCNE) por deficiencia de un piruvato quinasa, en una niña de 12 años de edad. Del estudio familiar, inicialmente orientado en su diagnóstico por una prueba positiva del cianuro ascorbato, se sugiere el posible caracter doble heterocigoto de la deficiencia en la paciente, eventualmente dada por dos variables enzimáticas por cooperación negativa