Hemoglobina Denver, una causa de desaturación en oximetría de pulso. Reporte de caso en un paciente pediátrico / Hemoglobin Denver, a cause of desaturated pulse oximetry. A pediatric case report

Las hemoglobinopatías son trastornos genéticos que afectan a la molécula de hemoglobina (Hb). Las mutaciones en las cadenas a o b que alteran el tetrámero de Hb pueden modificar la capacidad de la molécula para unirse al oxígeno. Las hemoglobinopatías con baja afinidad al oxígeno pueden presentarse con cianosis y una lectura alterada de la oximetría de pulso, lo que lleva a pruebas innecesarias y, a veces, invasivas para descartar afecciones cardiovasculares y respiratorias. En el siguiente reporte de caso, presentamos a una paciente pediátrica, asintomática, que se presentó a la consulta por detección de desaturación en oximetría de pulso. Las pruebas de laboratorio iniciales mostraron una anemia normocítica, normocrómica. Las muestras de gas venoso demostraron una p50 elevada. Después de extensas herramientas de diagnóstico, se diagnosticó una variante de Hb con baja afinidad al oxígeno, Hb Denver.

Hemoglobinopathies are genetic disorders that affect the hemoglobin (Hb) molecule. Mutations in the alpha or beta chains altering the Hb tetramer may modify the molecule's oxygen-binding capacity. Hemoglobinopathies with low oxygen affinity may occur with cyanosis and an altered pulse oximetry reading, leading to unnecessary and sometimes invasive tests to rule out cardiovascular and respiratory conditions. In the case report described here, we present an asymptomatic pediatric patient who consulted for desaturated pulse oximetry. Her initial laboratory tests showed normocytic, normochromic anemia. Venous blood gas samples showed an elevated p50. After using extensive diagnostic tools, a variant of Hb with low oxygen affinity was diagnosed: Hb Denver.

Hemoglobin Denver, a cause of desaturated pulse oximetry. A pediatric case report. / Hemoglobina Denver, una causa de desaturación en oximetría de pulso. Reporte de caso en un paciente pediátrico.

Hemoglobinopathies are genetic disorders that affect the hemoglobin (Hb) molecule. Mutations in the alpha or beta chains altering the Hb tetramer may modify the molecule's oxygen-binding capacity. Hemoglobinopathies with low oxygen affinity may occur with cyanosis and an altered pulse oximetry reading, leading to unnecessary and sometimes invasive tests to rule out cardiovascular and respiratory conditions. In the case report described here, we present an asymptomatic pediatric patient who consulted for desaturated pulse oximetry. Her initial laboratory tests showed normocytic, normochromic anemia. Venous blood gas samples showed an elevated p50. After using extensive diagnostic tools, a variant of Hb with low oxygen affinity was diagnosed: Hb Denver.

Las hemoglobinopatías son trastornos genéticos que afectan a la molécula de hemoglobina (Hb). Las mutaciones en las cadenas a o b que alteran el tetrámero de Hb pueden modificar la capacidad de la molécula para unirse al oxígeno. Las hemoglobinopatías con baja afinidad al oxígeno pueden presentarse con cianosis y una lectura alterada de la oximetría de pulso, lo que lleva a pruebas innecesarias y, a veces, invasivas para descartar afecciones cardiovasculares y respiratorias. En el siguiente reporte de caso, presentamos a una paciente pediátrica, asintomática, que se presentó a la consulta por detección de desaturación en oximetría de pulso. Las pruebas de laboratorio iniciales mostraron una anemia normocítica, normocrómica. Las muestras de gas venoso demostraron una p50 elevada. Después de extensas herramientas de diagnóstico, se diagnosticó una variante de Hb con baja afinidad al oxígeno, Hb Denver.

Nuevos aspectos moleculares y fisiopatológicos de la anemia drepanocítica / New molecular and pathophysiological aspects of sickle cell anemia

Introducción: La enfermedad por hemoglobina S es una anemia hemolítica crónica hereditaria cuyas manifestaciones clínicas provienen de la tendencia de esta hemoglobina de polimerizar y deformar los eritrocitos dándoles la típica forma de media luna, platanito, drepanocitos o sickle cell; de aquí el nombre de anemia drepanocítica o sicklemia. Objetivo: Describir los nuevos aspectos moleculares, fisiopatológicos y el diagnóstico de la anemia drepanocítica. Métodos: Se realizó una revisión de la literatura, en inglés y español, a través del sitio web PubMed y el motor de búsqueda Google académico de artículos publicados en los últimos 10 años. Se hizo un análisis y resumen de la bibliografía revisada. Conclusiones: La comprensión de la complejidad y multiplicidad de eventos que conducen a complicaciones graves en la anemia drepanocítica y nuestra incapacidad para predecir el curso clínico en cada caso particular ayudaría en la prevención de estos eventos(AU)

Introduction: Hemoglobin S disease is a hereditary chronic hemolytic anemia whose clinical manifestations come from the tendency of this hemoglobin to polymerize and deform erythrocytes, giving the typical crescent, banana, sickle cell or sickle cell shape; hence the name sickle cell anemia or sicklemia. Objective: To describe the new molecular and pathophysiological aspects and the diagnosis of sickle cell anemia. Methods: A literature review was carried out, in English and Spanish, through PubMed website and Google academic search engine for articles published in the last 10 years. An analysis and summary of the revised bibliography was made. Conclusions: Understanding the complexity and multiplicity of events that lead to serious complications in sickle cell anemia and our inability to predict the clinical course in each particular case would help preventing these events(AU)

[Molecular identification of Hemoglobin D Punjab in cases detected in two families]. / Identificación molecular de la hemoglobina D Punjab en dos familias.

BACKGROUND: Hemoglobin D Punjab is the world most common variant hemoglobin D; in Mexico there are reports of isolated cases. Our goal is to present the clinical and molecular study in two families with HbD Punjab. The objective was to submit molecular diagnosis of two families with Hb D Punjab and clinical features. CLINICAL CASE: Family 1: neonate with maternal history of HbS carrier. Father and sister with natural variants for the evaluated mutations, mother, brother and index case were heterozygous for HbD Punjab. Family 2: neonate with positive neonatal screening for detection of abnormal hemoglobins. Mother and index case were heterozygous for HbD Punjab, homozygous for HFE H63D, and Gilbert's syndrome UGT1A1*28 heterozygous. Father heterozygous for HFE H63D and sister homozygous for such mutation. The study of two families for HbD Punjab, HbS, ß-thalassemia, HFE and Gilbert syndrome was performed by real time PCR. CONCLUSION: The molecular identification of HbD Punjab is an accessible methodological proposal that can adequately distinguish carriers subjects; through this method two additional cases, one initially identified as HbS.

Introducción: la hemoglobina D Punjab (HbD Punjab) es la variante mundial más frecuente de hemoglobina D. En México se tienen reportes de casos aislados. El objetivo es presentar el diagnóstico molecular de dos familias con HbD Punjab y sus características clínicas. Casos clínicos: familia 1: neonato cuya madre era portadora de HbS. El padre y la hermana tenían variante natural para las mutaciones evaluadas, madre, hermano y caso índice heterocigotos para HbD Punjab. Familia 2: neonato con tamiz neonatal positivo para la detección de hemoglobinas anormales. Madre y caso índice fueron heterocigotos para HbD Punjab, homocigotos para HFE H63, y heterocigotos para síndrome de Gilbert UGT1A1*28. Padre, heterocigoto para HFE H63D, y hermana homocigoto para dicha mutación. El estudio de las dos familias para HbD Punjab, HbS, beta-talasemia, HFE y síndrome de Gilbert se hizo mediante PCR en tiempo real. Conclusión: la identificación molecular de la HbD Punjab es una propuesta metodológica accesible y permite diferenciar adecuadamente a los portadores. A través de esta metodología se identificaron dos casos adicionales en nuestro país, uno de ellos identificado inicialmente como HbS.

Hemoglobinopathy detection through an institutional neonatal screening program in Colombia / Detecção de hemoglobinopatias por meio de um programa institucional de triagem neonatal na Colômbia

ABSTRACT Introduction: Hemoglobinopathies are among the most common genetic disorders of hemoglobin worldwide and a public health problem. In Colombia, even though geographical areas with high incidence of this disorder have been reported, the absence of a national screening program does not permit us to determine its prevalence. Objective: Establish the prevalence of hemoglobin variants in a population covered by the neonatal screening program of Clínica Colsanitas S.A., between June 2000 and December 2014, including eight capital cities in Colombia. Methods: A retrospective cross-sectional study was conducted. We collected data from reports of the neonatal hemoglobinopathy-screening program for full-term newborn babies between 5 and 15 days old. Qualitative hemoglobin analysis was performed using gel electrophoresis of blood samples taken from the babies' heels. Results: The overall prevalence of abnormal Hb was 1.3%. Within the groups of newborns affected with any hemoglobinopathy (n = 400), the most frequent abnormal structural hemoglobins found were HbS (43%), HbC (9%), fast Hb (8%). For quantitative hemoglobins, HbA2 was 3.7% and HbA kept slightly elevated in 14.7% of cases. Frequency of homozygosis for HbS was 0.01%. Barranquilla, Cartagena and Cali were the cities with the greatest frequency of hemoglobinopathies. No correlation between sex and abnormal hemoglobin was found. Discussion and conclusion: Taking in consideration data from the World Health Organization (WHO) on hemoglobinopathies, our prevalence of > 1% is considered high. Therefore, a more extended coverage and the need for a national screening program are priorities.

RESUMO Introdução: As hemoglobinopatias são doenças genéticas comuns em todo o mundo e representam um problema de saúde pública. Na Colômbia, embora existam áreas geográficas com maior risco de apresentá-las, não há programas de triagem nem estudos para estabelecer sua prevalência na população. Objetivo: Estabelecer a prevalência de variantes de hemoglobina (Hb) na população pertencente ao programa de triagem neonatal da Clínica Colsanitas S.A. entre junho de 2000 e dezembro de 2014, em oito cidades do país. Métodos: Estudo transversal retrospectivo. Os registros do programa de triagem neonatal das hemoglobinopatias foram revistos para a informação dos resultados de eletroforese de hemoglobina em pH alcalino, praticada no sangue dos recém-nascidos com idades compreendidas entre 5-15 dias. Resultados: A prevalência geral de Hb anormal foi de 1,3%. Dentro dos grupos de recém-nascidos afetados com qualquer hemoglobinopatia (n = 400), as hemoglobinas anormais estruturais mais frequentes foram hemoglobina S (HbS) (43%), hemoglobina C (HbC) (9%) e Hb rápida (8%). Para as Hb quantitativas, o aumento da hemoglobina A2 (HbA2) foi de 3,7%, e a hemoglobina A (HbA) aumentada permaneceu ligeiramente elevada em 14,7% casos. A frequência de homozigotos para HbS foi de 0,01%. Barranquilla, Cartagena e Cali foram as cidades com maior frequência de hemoglobinopatias. Não houve associação entre sexo e presença de algum tipo de Hb. Discussão e conclusão: A prevalência global de hemoglobinopatias em nosso estudo foi alta (> 1%) de acordo com os critérios da Organização Mundial de Saúde (OMS). Portanto, há a necessidade de implementação de programas de triagem neonatal com maior cobertura nacional para as hemoglobinopatias.

[Hemoglobin Woodville associated with double point mutation in the gene of glucose-6-phosphate dehydrogenase]. / Hemoglobina Woodville asociada a una doble mutación puntual en el gen de la glucosa-6-fosfato deshidrogenasa.

The co-inheritance of erythrocyte defects, hemoglobinopathies, enzymopathies, and membranopathies is not an unusual event. For the diagnosis, a laboratory strategy, including screening and confirmatory tests, additional to molecular characterization, was designed. As the result of this approach, a 24-year-old man carrying a hemoglobinopathy (Hemoglobin Woodville) and an enzymopathy (glucose-6-phosphate dehydrogenase deficiency) was identified. In the heterozygous state hemoglobin Woodville, is asymptomatic, and homozygous or double heterozygous individuals have not been reported thus far. On the other hand, previously described double point mutation in the gene for glucose-6-phosphate dehydrogenase c. [202G>A; 376A>G], p. [Val 68Met; Asn126Asp], causes hemolysis of varying severity after food or drug intake or infections. This case highlights the importance of the methodology carried out for the diagnosis, treatment, and proper genetic counseling.

Improvements in phenotype studies of hemoglobin disorders brought by advances in reversed-phase chromatography of globin chains.

INTRODUCTION: Phenotype studies still occupy a key position in the diagnosis of hemoglobin (Hb) disorders. MATERIAL AND METHODS: In addition to the conventional methods for diagnosis of Hb disorders which are mostly based on differences in charge of the Hb molecules, some progresses have been brought by studying other properties of the globin chains. Among those, difference in hydrophobicity that may be investigated by reversed-phase HPLC (RP-HPLC) discriminates between variants displaying identical charges. RESULTS: In this study, we show how an update of this method allows to recognize an α-chain variant from a γ-chain variant, a problem frequently during neonatal screening. We illustrate that RP-HPLC may also unravel unclear phenotypes which are modified by the presence of an additional variant not detected by the conventional methods, and help to characterize rare mutants. Also we show that it allows a clear distinction between variants with identical electrophoretical charges as exemplified by Hb Lepore Boston-Washington and Lepore Baltimore. CONCLUSIONS: In view of our results, RP-HPLC is a technique that needs to be used as a second step in the general strategy for a correct characterization of Hb variants.

Molecular analysis of abnormal hemoglobins in beta chain in Aegean region of Turkey and first reports of hemoglobin Andrew-Minneapolis and Hb Hinsdale from Turkey.

OBJECTIVES: The Agean is one of the regions in Turkey where thalassemias and abnormal hemoglobins (Hbs) are prevalent. Combined heterozygosity of thalassemia mutations with a variety of structural Hb variants lead to an extremely wide spectrum of clinical and hematological phenotypes which is of importance for prenatal diagnosis. METHODS: One hundred and seventeen patients and carriers diagnosed by hemoglobin electrophoresis (HPLC), at risk for abnormal hemoglobinopathies were screened for mutational analysis of the beta-globin gene. The full coding the 5' UTR, and the 3' UTR sequences of beta-globin gene (GenBank accession no. U01317) were amplified and sequenced. RESULTS: In this study, a total of 118 (12.24%) structural Hb variant alleles were identified in 1341 mutated beta-chain alleles in Medical Genetics Department of Ege University between January 2006 and November 2013. DISCUSSION: Here, we report the mutation spectrum of abnormal Hbs associated with the beta-globin gene in Aegean region of Turkey. CONCLUSION: In the present study, the Hb Hinsdale and Hb Andrew-Minneapolis variants are demonstrated for the first time in the Turkish population.

Prevalence of ß-thalassemia trait and abnormal hemoglobins in Sanliurfa Province in southeast Turkey.

Thalassemia is one of the most common hereditary disorders in Turkey, especially in the Mediterranean region of the country. The purpose of this study was to determine the frequency of the ß-thalassemia (ß-thal) trait and abnormal hemoglobins (Hbs) in couples who applied for premarital screening in Sanliurfa Province, in the southeastern region of Turkey, a province with the first reported incidence of ß-thal and abnormal Hbs. In the present study, in order to detect the prevalence of the ß-thal trait and abnormal Hbs in Sanliurfa Province, Turkey, a total of 37,962 couples who applied for premarital screening were analyzed. From January 2011 through March 2014, red blood cell (RBC) counts and Hb fractionation were carried out by a cell counter and high performance liquid chromatography (HPLC), respectively. The prevalence of ß-thal with high Hb A2 (>3.5%) values was found at rates of 2.44% (n = 1853) in Sanliurfa Province. Additionally, the abnormal Hb rate was 1.57% (1193/75,924), and Hb S (HBB: c.20T > A), Hb C (HBB: c.19G > A) and Hb D-Punjab (HBB: c.364G > C) were reported as 0.50, 0.38 and 0.69, respectively. This study is the first to establish the frequency of ß-thal and abnormal Hbs in Sanliurfa Province, which has the highest birth frequency. We report that the frequency of the ß-thal trait is at a high-risk level compared to other cities in Turkey. Due to the high risk of ß-thal in Sanliurfa Province, a premarital screening program would be of great value in informing parents about offspring with ß-thal.