Neutropenia congénita de tipo IV: reporte de un caso / Congenital neutropenia type IV: case report

La neutropenia congénita grave (NCG) es una entidad heterogénea cuya característica común es un recuento absoluto de neutrófilos inferior a 0,5 x 10 9/l. Presenta gran heterogeneidad genética, las mutaciones más frecuentes son las del gen de la elastasa 2 (ELA 2). El tratamiento de primera elección es la administración de factor estimulador de colonias de granulocitos. Los pacientes con NCG presentan infecciones graves en etapas tempranas de la vida. Se presenta una paciente con NCG asociada a fenotipo peculiar con facies triangular, retromicrognatia, patrón venoso prominente en miembros inferiores, comunicación interauricular y mal progreso ponderal, en quien se diagnosticó déficit de la enzima glucosa 6 fosfato deshidrogenasa, subunidad catalítica 3 (G6PC3). A pesar de lo infrecuente de esta mutación como causa de NCG (2 %), su conocimiento cobra importancia porque la coexistencia del fenotipo característico con una NCG orienta en la solicitud del estudio genético que permite arribar al diagnóstico.

Severe congenital neutropenia (SCN) is a heterogeneous disease whose more common feature is an absolute neutrophil count less than 0.5 x 10 9/l. It presents great genetic heterogeneity. Autosomal dominant inherited mutations of the elastase 2 gene (ELA2) represent the most common etiology. The first choice treatment is the administration of granulocyte colony stimulating factor. Patients with SCN develop severe infections early in life. We present a patient who associated SCN to a peculiar phenotype, characterized by triangular facies, retromicrognathia, prominent venous pattern in the lower limbs, atrial septal defect and poor weight progress, in whom a deficiency of the enzyme glucose 6 phosphate dehydrogenase, a catalytic subunit 3 (G6PC3), was diagnosed. Despite the infrequency of this mutation as the origin of SCN (2%), its knowledge becomes important because the coexistence of the characteristic phenotype and SCN guides the request for the genetic study that allows reaching the diagnosis.

Genetic Mutation Characteristics of Glucose-6-Phosphate Dehydrogenase Deficiency Patients in Wuhan / 中国实验血液学杂志

OBJECTIVE@#To explore the genotype mutation characteristics of patients with glucose-6-phosphate dehydrogenase(G6PD) deficiency in Wuhan.@*METHODS@#A total of 1 321 neonates with positive screening and outpatients were received G6PD mutation detection, 12 kinds of common G6PD mutation in Chinese people was detected by using multicolor melting curve analysis (MMCA) method, for those with negative results, the enzyme activity and clinical information were analyzed, sequencing was recommended after informed consent when it is necessary.@*RESULTS@#Among 1321 patients, a total of 768 mutations were detected out, with a detection rate of 58.1%. A total of 18 types of G6PD genotypes were identified, including c.1388G>A, c.1376G>T, c.95G>A, c.1024C>T, c.871G>A, c.392G>T, c.487G>A, c.1360C>T, c.1004C>A, c.517T>C, c.592C>T, c.94C>G, c.152C>T, c.320A>G, c.1028A>G, c.1316G>A, c.1327G>C and c.1376G>C, including 683 male hemizygotes, 3 female homozygotes, 80 female heterozygotes and 2 female compound heterozygous.@*CONCLUSION@#A total of 18 types of G6PD mutations are identified in the reaserch, and c.94C>G, c.1028A>G and c.1327G>C are first reported in Chinese population. The most common G6PD mutation types in Wuhan are c.1388G>A, c.1376G>T, c.95G>A.

Screening results and genetic features of glucose-6-phosphate dehydrogenase deficiency in 54 025 preterm infants in Chengdu, China / 中国当代儿科杂志

OBJECTIVE@#To analyze the screening results of glucose-6-phosphate dehydrogenase (G6PD) deficiency and gene mutation distribution of G6PD deficiency in preterm infants in Chengdu, China, in order to provide a basis for the improvement of G6PD screening process in preterm infants.@*METHODS@#Fluorescent spot test for G6PD deficiency using dried blood spots was used for G6PD screening of 54 025 preterm infants born from January 1, 2015 to December 31, 2019 in Chengdu, and G6PD enzymology and gene detection were used for the diagnosis of 213 infants with positive screening results.@*RESULTS@#Among the 54 025 preterm infants, 192 were diagnosed with G6PD deficiency, with an incidence rate of 3.55‰. The incidence rate of G6PD deficiency in preterm infants was higher than that in full-term infants in the same period of time and tended to increase year by year. Birth in summer, gestational age T mutation tend to have mild conditions.

G6PD deficiency in Latin America: systematic review on prevalence and variants

Plasmodium vivax radical cure requires the use of primaquine (PQ), a drug that induces haemolysis in glucose-6-phosphate dehydrogenase deficient (G6PDd) individuals, which further hampers malaria control efforts. The aim of this work was to study the G6PDd prevalence and variants in Latin America (LA) and the Caribbean region. A systematic search of the published literature was undertaken in August 2013. Bibliographies of manuscripts were also searched and additional references were identified. Low prevalence rates of G6PDd were documented in Argentina, Bolivia, Mexico, Peru and Uruguay, but studies from Curaçao, Ecuador, Jamaica, Saint Lucia, Suriname and Trinidad, as well as some surveys carried out in areas of Brazil, Colombia and Cuba, have shown a high prevalence (> 10%) of G6PDd. The G6PD A-202A mutation was the variant most broadly distributed across LA and was identified in 81.1% of the deficient individuals surveyed. G6PDd is a frequent phenomenon in LA, although certain Amerindian populations may not be affected, suggesting that PQ could be safely used in these specific populations. Population-wide use of PQ as part of malaria elimination strategies in LA cannot be supported unless a rapid, accurate and field-deployable G6PDd diagnostic test is made available.

Heterogeneidade do diabetes melito tipo 1 / Heterogeneity of type 1 diabetes mellitus

O diabetes melito tipo 1 (DM1) caracteriza-se pela deficiência de insulina por causa da destruição das células-beta pancreáticas. O DM1 atualmente é classificado em dois subtipos: um auto-imune (DM1A) e outro não auto-imune (DM1B). O DM1A poligênico (isolado ou associado a outras doenças auto-imunes) é a forma mais prevalente. O DM1A pode fazer parte de síndromes raras em virtude de alterações monogênicas [gene regulador da auto-imunidade (AIRE)] e mutações no gene FOX-p3. O DM1B corresponde de 4 por cento a 7 por cento do DM1 e pode incluir formas não clássicas, como o diabetes fulminante e o DATC. Jovens com DM1A e sinais de resistência à insulina associados têm sido denominados de diabetes duplo (DD), tipo 1 e tipo 2. Nessa revisão são discutidas as patofisiologias e as características clínicas das formas raras de DM1A, o DM1B, as formas atípicas de DM1 não auto-imune e as inter-relações entre a inflamação subclínica da obesidade e o processo auto-imune do DM1A no DD. Em resumo, apresentamos o conceito de heterogeneidade do DM1.

Type 1 diabetes (T1D) comprises all forms of autoimmune-mediated and idiopathic beta-cell destruction leading to absolute insulin deficiency. The etiological heterogeneity of T1D has been recognized for the last decades, but it has been divided into only two subtypes so far: autoimmune (T1D)A and non-autoimmune (T1D)B mediated. Polygenic T1DA (isolated or associated to other autoimmune diseases) is the most prevalent type of T1D. T1DA might be part of rare monogenic syndromes related to mutations in the autoimmune regulator gene (AIRE) and FOXp3. Non-autoimmune forms of T1D correspond to approximately 4 to 7 percent of newly diagnosed T1D and include T1DB, as well as other types of atypical diabetes, for example fulminant type 1 diabetes and adult ketosis-prone diabetes. A new expression of diabetes in young with insulin resistance and obesity, along with the presence of pancreatic autoimmunity markers, namely auto-antibodies to islet cell antigens, is called double diabetes (DD), T1DA plus type 2 diabetes. Evidence has been collected concerning the potential effect of obesity-linked cytokines in amplifying the autoimmune response in DD. Therefore all these issues are presented and discussed in this review as the concept of heterogeneity of Type 1 Diabetes.

Acute Hemolysis and Renal Failure caused by Hepatitis A Infection with Underlying Glucose-6-Phosphate Dehydrogenase Deficiency / 대한진단검사의학회지

Although glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common enzyme disorder worldwide, it has rarely been reported among Korean. The patient was previously healthy 39 yr old male who showed severe hemolytic anemia and acute renal failure accompanied by hyperbilirubinemia after hepatitis A infection. The additional studies for differential diagnosis of hemolytic anemia showed a moderate deficiency of G6PD enzyme. Because hepatitis A infection in patient with G6PD deficiency present much more severe clinical symptoms, G6PD enzyme should be examined in patients with triggering factors of hemolysis such as hepatitis A infection.

Screening for haemoglobinopathies and G6PD deficiency among the Mizos of Mizoram: a preliminary study.

The population of North-eastern region of India is of different tribes, races and ethnic backgrounds. The study of abnormal haemoglobins and G6PD has been usefully utilized in population genetics to evaluate the nature and extent of selective forces operating in a population. Data on haemoglobinopathies and G6PD deficiency is still not available from the State of Mizoram. The present study was aimed to document the frequency of these genetic traits in the Mizos of Mizoram. Blood samples in the form of dried filter paper spots collected from 490 Mizos were subjected to haemoglobin electrophoresis in starch agar gel for detection of haemoglobin variants and fluorescent spot test was conducted for screening of G6PD deficiency. Hb E was the only haemoglobin variant detected. The prevalence of the carreer state was documented to be 1.5%. G6PD deficiency was prevalent in 17.5% of this population. The prevalence of Hb E was much lower and that of G-6PD deficiency was found to be much higher than what has been reported from most other states of the north-eastern region of India. This might point towards a different ethnic origin of this population.

Glucose-6-phosphate dehydrogenase deficiency in India.

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the commonest red cell enzymopathy in humans and has an X-linked inheritance. It has been reported from India more than 30 years ago and the prevalence varies from 0-27% in different caste, ethnic and linguistic groups. The major clinical manifestations are drug induced hemolytic anemia, neonatal jaundice and chronic non-spherocytic hemolytic anemia. Individuals with G6PD deficiency have a selective advantage against falciparum malaria. Thirteen biochemically characterized variants have been reported from India. At the molecular level, G6PD Mediterranean is the most common deficient variant in the caste groups whereas, G6PD Orissa is more prevalent among the tribal of India. The third common variant seen in India is G6PD Kerala-Kalyan.

Red cell glucose-6-phosphate dehydrogenase phenotypes in Iraq

We attempted to characterize biochemically glucose-6-phosphate dehydrogenase [G6PD] variants in Iraqi individuals. Thus 758 healthy Iraqi males aged 18-60 years were randomly selected and 46 [6.1%] were G6PD deficient. Although the predominant non-deficient G6PD phenotype was G6PD B [92.6%], G6PD A+ was found in polymorphic frequency [1.3%]. In the deficient group, 31 cases were fully characterized, including 17 cases with features consistent with G6PD Mediterranean variant, while 12 had other biochemical features and were labelled as non-Mediterranean variant. The remaining two deficient cases were characterized as G6PD A- variant. The presence of a significant number of non-Mediterranean variant was unexpected and may be related to the more heterogeneous background of the Iraqi people

Red cell enzymopathies as a model of inborn errors of metabolism.

The molecular abnormalities of erythroenzymopathies associated with hereditary hemolytic anemia have been determined using molecular techniques. Pyruvate kinase (PK) deficiency is the most common and well-characterized enzyme deficiency involving the glycolytic pathway and causing hereditary hemolytic anemia. We have identified six distinct missense mutations and a form of splicing mutation in 11 unrelated families with homozygous PK deficiency. Mutations located near the substrate binding site may change the conformation of the active site, resulting in a drastic loss of activity and severe clinical symptoms. Up to now, including these genetic defects, 21 missense, 1 nonsense and 2 splicing mutations, 2 insertions, and 3 deletions have been determined. G6PD deficiency is the most common metabolic disorder, and is associated with chronic and drug- or infection-induced hemolytic anemia. To date, sixty different mutations have now been identified. Except for three kinds of variants with small gene deletions or three nucleotide substitutions, all of those were found to be produced by one or two nucleotide substitutions. Molecular studies disclosed that all the class 1 variants associated with chronic hemolysis have the mutations surrounding either the substrate or the NADP binding site. Among rare enzymopathies, missense mutations have been determined in glucosephosphate isomerase deficiency, aldolase deficiency, triosephosphate isomerase (TPI) deficiency, phosphoglycerate kinase deficiency, and adenylate kinase deficiency. Compound heterozygous cases with missense mutation/nonsense mutation and missense mutation/decreased mRNA have been reported in TPI deficiency and diphosphoglyceromutase deficiency, respectively. In phosphofructokinase (PFK) deficiency, three kinds of 5'-splice junction mutations resulting in abnormally spliced PFK-M mRNA were identified. An exception is a hemolytic anemia due to increased adenosine deaminase activity. The basic abnormality appears to result from overproduction of structurally normal enzyme.

Characterization of a variant glucose-6-phosphate dehydrogenase from the south Indian population.

Glucose-6-phosphate dehydrogenase (G6PD) is coded by a gene on the X-chromosome. Earlier studies have shown that the South Indian population has a high incidence of this enzyme deficiency. The electrophoretic mobility, pH optimum and the Km values for G6PD from normal and variant individuals were identical. However, the specific activity of the variant enzyme was 8 times less compared to the value of the normal enzyme. Western blot analysis of partially purified G6PD from normal and variant individuals performed using equal amounts of total protein showed that the variant protein was 3 times less in concentration. Similar analysis performed using protein corresponding to equal enzyme activity units in the normal and variant samples showed that the variant enzyme was 2.25 times less efficient compared to the normal enzyme. RNA dot blot analysis using full length G6PD cDNA probe (PGDT5B, a kind gift from Prof. L Luzzatto) revealed that lymphocytes from normal and variant individuals had equal amounts of G6PD specific mRNA.

Characterization of G6PD Rohini--a new class III Indian variant.

A new Indian G6PD variant was detected in a 15 yr old Maratha male during a population screening programme in high school children in Bombay (India). The propositus and two family members having the same variant were apparently healthy. This enzyme variant has a mild erythrocyte G6PD deficiency and a slow electrophoretic mobility. It is characterized by a high Michaelis-Menton constant for G6P, a bimodal curve for pH optima and a slight decrease in the thermostability. The rate of utilization of substrate analogue is similar to that of normal. These observations suggest identification of a new class III variant, designated as G6PD Rohini.

Gd(-) Carapicuiba, a rare glucose-6 phosphate dehydrogenase variant associated with moderate enzyme deficiency and chronic hemolysis

A 27 year old Brazilian male of both Portuguese and Spanish origin presenting nonspherocytic chronic hemolytic anemia was found to have a rare glucose-6-phosphate dehydrogenase variant herein named Gd(-) Carapicuiba. The red blood cell enzyme variant is characterized by a moderate enzyme deficiency (47%), high Km for its substrates G6P and NADP, decreased activity against deamino-NADP, increased Ki for NADPH and decreased heat stability. The clinical signs of the patient are probably related to these properties of the enzyme variant

Frequency of five genetic polymorphisms in two populations of Colombia

As prevalências dos alelos dos sistemas da glicose-6-fosfato desidrogenase (G6PD), hemoglobina (Hb), ABO, Rh e haptoglobina (Hb) foram investigadas em duas populaçöes colombianas miscigenadas de origem predominantemente indígena (da tribo Noanama) e africana. Entre os negróides os marcadores para G6PD, Rh e Hp mostraram as freqüências esperadas, mas os valores relativamente altos encontrados para Hb*C (0,057) e ABO*O (0,853), assim como o baixo para ABO*B (0,046), devem ser enfatizados. Os resultados relativos à hemoglobina podem ser explicados por imigraçäo de pessoas de áreas com altas prevalências de Hb*C na Africa, ou sobrevivência diferencial de portadores deste gene na Colombia; enquanto os achados no ABO podem refletir mistura com Ameríndios. A presença de um indivíduo deficiente para G6PD, assim como a ocorrência de Hb*C (0,106), ABO*A (0,260) e ABO*B (0,027) entre aqueles classificados como Ameríndios sugere nível alto de mistura, mas a ausência de Rh (-) entre eles está de acordo com o esperado. O número de tipagens para haptoglobina realizadas neste grupo foi baixo; a freqüência observada de Hp*1 (0,700) é similar à encontrada em índios sul-americanos em geral, mas difere da prevalência observada em um estudo prévio de índios Noanama