Recém-nascido com deficiência de glicerol quinase: um caso clínico / Neonate with glycerol kinase deficiency: A clinical case

OBJETIVOS: Relatar o caso de um recém-nascido com deficiência de glicerol quinase, no qual foi identificada uma mutação isolada ainda não descrita no gene GK. DESCRIÇÃO DO CASO: Um recém-nascido com 10 dias de vida foi trazido ao serviço de urgência por recusa alimentar com 24 horas de evolução. Ao exame físico apresentava perda de 31% do peso de nascimento e sinais de desidratação. Os exames laboratoriais constataram presença de acidose metabólica com anion gap aumentado, creatinina 2,41mg/dL, ureia 306 mg/dL, hipernatremia (182mEq/L), hipercalemia (6,8mEq/L), hipercloremia (151mEq/L), transaminase glutâmico-oxalacética 879U/L, transaminase glutâmico-pirúvica 243U/L, triglicerídeos 725mg/dL. A cromotagrafia de ácidos orgânicos revelou hiperglicerolemia e glicerolúria compatíveis com deficiência de glicerol quinase. O estudo genético revelou uma mutação ainda não descrita: c.187T>C (p.S63P) em hemizigotia no gene GK. CONCLUSÕES: A causa mais frequente de desidratação hipernatrêmica no período neonatal é a hipogalatia materna. Nos casos mais graves de desidratação outras etiologias devem ser consideradas, incluindo causas metabólicas como a deficiência de glicerol quinase. Neste caso foi encontrada uma mutação no gene GK ainda não descrita.

AIMS: To report the case of a newborn with glycerol kinase deficiency, in which an isolated mutation not yet described in the GK gene was identified. CASE DESCRIPTION: A neonate with 10 days of age was brought to the emergency department for refusal to feed with 24 hours of evolution. Physical examination showed a loss of 31% of birth weight and signs of dehydration. Laboratory tests revealed a metabolic acidosis with increased anion gap, creatinine 2.41mg/dL, urea 306mg/dL, hypernatremia (182mEq/L), hyperkalemia (6.8mEq/L), hyperchloremia (151mEq/L), glutamic-oxalacetic transaminase 879U/L, glutamic-pyruvic transaminase 243U/L, triglycerides 725mg/dL. Chromotagraphy of organic acids revealed hyperglycerolemia and glyceroluria compatible with glycerol kinase deficiency. The genetic study revealed a mutation not yet described: c.187T>C (p.S63P) as hemizygote status in the GK gene. CONCLUSIONS: The most frequent cause of hypernatremic dehydration in the neonatal period is maternal hypogalactia. In more severe cases of dehydration, other etiologies should be considered, including metabolic causes such as glycerol kinase deficiency. In this case a mutation not yet described in the GK gene was found.

Advances in diagnosis and treatment of complex glycerol kinase deficiency / 国际儿科学杂志

Glycerol kinase deficiency is an X chromosome recessive genetic metabolic defects,of which 90％ patients are male.Glycerol kinase deficiency is often sporadic,but sometimes inheritary.It is rare and can be divided into simple type and complex type.Complex glycerol kinase deficiency,also known as Xp21 associated gene deletion syndrome,has clinical manifestation that appears to be a syndrome of several isolated gene defects,including congenital adrenal dysplasia,hypertriglyceridemia,Duchenne muscular dystrophy,and is often misdiagnosed.Complex glycerol kinase deficiency is rare,often has early onset.If not treated timely,it can cause death even in the neonate.There is no effective cure for this disease,and the only choice is symptomatic treatment and limitting the intake of fat.For instance,when glycerol kinase deficiency is accompanied by adrenal cortical dysfunction,it usually requires the early alternative treatment of adrenal cortex hormones to prevent the occurrence of adrenal crisis.All clinicians should improve the understanding of the disease.This review is focused on the introduction of pathogenic characteristics,clinical features,genetic characterstics,genetic counseling,treatment and prognosis of complex glycerol kinase deficiency.

Complex glycerol kinase deficiency: two case report and literature review / 临床儿科杂志

Objective To explore the clinical and genetic characteristics of complex glycerol kinase deficiency (GKD). Methods The clinical data of 2 cases of complex GKD were analyzed and the related literatures were reviewed. Results Both cases were male onset in neonatal period, and had hypocorticalism (hyponatremia, hyperkalemia, dehydration), hypercreatine kinasemia, and pseudotriglyceridemia. Gene detection suggested that there was gene deletion in chromosome Xp21 region. In the follow-up, one case had good control of the disease and one died of infection. Conclusions Complex GKD is an X-linked recessive hereditary disease. It is rare and complicated, and is easily misdiagnosed. Early diagnosis and treatment are beneficial to improve the prognosis.

Using Pichia pastoris to produce recombinant glycerol kinase / Produção de glycerol quinase recombinante utilizando o sistema Pichia pastoris

The methylotrophic yeast Pichia pastoris has been developed into an efficient expression system for the production of recombinant protein under the tight control of the methanol-induced alcohol oxidase promoter (pAOX1). In this study, a 2.5-liter culture system was developed for the growth of a P. pastoris strain bearing the GUT1 gene from Saccharomyces cerevisiae for the expression of recombinant glycerol kinase (GK). The best culture conditions to produce high levels of secreted GK were investigated by growing the recombinant strain of P. pastoris in shake flasks and a fermenter. Cell growth and enzyme production were found to be optimal after two days of growth. Enzyme production was affected by the nitrogen source, Difco peptone being the most appropriate for this purpose. Three different rates of air flow (1 to 3 L/min) were tested to observe their effect on cell growth and the secretion of GK into a medium containing 1% methanol as the sole carbon source. Increasing the rate of air bubbling in the culture medium enhanced both cell growth and GK activity, reaching a dry biomass of 7.84 mg/mL, cell viability of 98.4% and a maximal GK activity of 1.57 U/mL, at a flow rate of 2.0 L/minute, at 30° C and pH 6.0. Moreover, the enzyme activity in the P. pastoris culture medium was 2.3 times higher under these conditions than in the shake-flask culture, demonstrating the significant influence of aeration on biomass production and GK activity secreted by P. pastoris...

A levedura metilotrófica Pichia pastoris possui um sistema de expressão eficiente para a produção de proteínas recombinantes. A indução da produção da proteína de interesse é feita com metanol, que é capaz de ativar a transcrição do gene de interesse clonado sob controle do promotor do gene AOX1. Um meio de cultura de 2.5 litros foi elaborado para o crescimento da cepa Pichia pastoris construída com o gene GUT1 de Saccharomyces cerevisiae para expressar a enzima recombinante glicerol quinase (GK). As condições ideais de cultura, para alcançar altos níveis de expressão de GK foram investigados em crescimentos realizados em frascos e fermentador. Crescimento celular e produção de enzima atingiram valores ótimos em dois dias de cultura. A produção enzimática foi afetada pela fonte de nitrogênio no meio. Peptona da marca Difco foi a fonte de nitrogênio mais adequada para a expressão destaenzima. Três diferentes concentrações (1-3 L / min) defluxo de ar foram analisados em ensaios de crescimento celular e secreção da GK, no meio contendo 1 % demetanol como única fonte de carbono. O aumento do fluxo do ar no meio de cultura produziu melhores resultados para o crescimento celular e atividade da GK, atingindo 7,84 mg / mL de biomassa seca e 98,4%de viabilidade. A máxima atividade de GK foi de 1,57U / mL, com a concentração de fluxo de ar de 2,0 L/ minuto a 30 ° C e pH 6.0. O aumento da atividade enzimática foi 2,3 vezes maior no meio de cultura da Pichia pastoris nestas condições, revelando a influência deste parâmetro na produção de biomassa e atividade da GK...

Covalent immobilization of lipase, glycerol kinase, glycerol-3-phosphate oxidase & horseradish peroxidase onto plasticized polyvinyl chloride (PVC) strip & its application in serum triglyceride determination.

Background & objectives: Reusable biostrip consisting enzymes immobilized onto alkylamine glass beads affixed on plasticized PVC strip for determination of triglyceride (TG) suffers from high cost of beads and their detachments during washings for reuse, leading to loss of activity. The purpose of this study was to develop a cheaper and stable biostrip for investigation of TG levels in serum. Methods: A reusable enzyme-strip was prepared for TG determination by co-immobilizing lipase, glycerol kinase (GK), glycerol-3-phosphate oxidase (GPO) and peroxidase (HRP) directly onto plasticized polyvinyl chloride (PVC) strip through glutaraldehyde coupling. The method was evaluated by studying its recovery, precision and reusability. Results: The enzyme-strip showed optimum activity at pH 7.0, 35oC and a linear relationship between its activity and triolein concentration in the range 0.1 to 15 mM. The strip was used for determination of serum TG. The detection limit of the method was 0.1 mM. Analytical recovery of added triolein was 96 per cent. Within and between batch coefficients of variation (CV) were 2.2 and 3.7 per cent, respectively. A good correlation (r=0.99) was found between TG values by standard enzymic colrimetric method employing free enzymes and the present method. The strip lost 50 per cent of its initial activity after its 200 uses during the span of 100 days, when stored at 4oC. Interpretation & conclusions: The nitrating acidic treatment of plasticized PVC strip led to glutaraldehyde coupling of four enzymes used for enzymic colourimetric determination of serum TG. The strip provided 200 reuses of enzymes with only 50 per cent loss of its initial activity. The method could be used for preparation of other enzyme strips also.

Síndrome de Sengers: comunicación de dos casos en Chile / Sengers syndrome: report of two cases in chile

El Síndrome de Sengers es una enfermedad mitocondrial autosómica recesiva, producida por mutación del gen de la Acil-Glicerol Kinasa (AGK), recientemente descubierto. Se caracteriza por cataratas congénitas bilaterales, miocardiopatía hipertrófica y acidosis láctica. Puede tener miopatía esquelética leve, intolerancia al ejercicio y desarrollo mental normal. Los pacientes fallecen tempranamente debido a falla cardíaca. Dada la alta letalidad, lo infrecuente de este síndrome y la presencia de un diagnóstico confirmado, se presenta el caso clínico de 2 hermanos chilenos, fallecidos por la enfermedad, que se presentaron con el cuadro característico de cataratas congénitas bilaterales, miocardiopa-tía hipertrófica y acidosis láctica. El mayor, se operó las cataratas a los 4 meses de edad y falleció a la edad de 13 meses debido a falla cardíaca severa refractaria y falla orgánica múltiple, descompensado por una infección respiratoria. El menor se diagnosticó a los 3 meses de edad y se le confirmó la mutación del gen de AGK en Alemania. Se decidió no operarlo de las cataratas dado el mal pronóstico vital. Presentó progresión de la miocardiopatía hipertrófica y falleció súbitamente a los 8 meses de edad.

Senger's Syndrome is a recessive autosomal mitochondrial disease due to a recently discovered mutation of the Acyl-Glycerol Kinase (AGK) gen,. It is characterized by congenital bilateral cataracts, progressive hypertrophic cardiomyopathy and lactic acidosis. It may present skeletal myopathy, exercise intolerance and usually normal mental development. Patients die early in life due to heart failure. The clinical cases of two brothers with a confirmed diagnosis of Senger's syndrome are reported. The older brother was operated on for cataracts at the age of 4 months and he died when he was 13 months old due to severe refractory heart failure and multi-organ failure, decompensated by a respiratory infection. The younger brother was diagnosed at 3 month of age and the AGK gene mutation was confirmed in Germany. Cataracts were not operated on due to the the patient's extremely poor prognosis. He had progressive hypertrophic cardiomyopathy and died suddenly at 8 month of age.

Two Cases of Xp21 Contiguous Gene Deletion Syndrome

On chromosome Xp21 region, several genes such as glycerol kinase (GK) gene, adrenal hypoplasia congenita gene and Duchenne muscular dystrophy gene are located contiguously. Xp21 contiguous gene deletion syndrome involves the glycerol kinase gene deletion together with the adrenal hypoplasia congenita and/or Duchenne muscular dystrophy gene. The clinical features of a patient with a Xp21 contiguous gene deletion syndrome are sum of each disease,psychomotor retardation and lethargy for glycerol kinase deficiency, hyperpigmentation and salt wasting dehydration for congenital adrenal hypoplasia and muscular weakness and hypotonia for Duchenne muscular dystrophy. We experienced and reviewed two cases of Xp21 contiguous gene deletion syndrome with literatures.

A Case of Xp21 Contiguous Gene Deletion Syndrome with Hyperglycerolemia, Congenital Adrenal Hypoplasia and Duchenne Muscular Dystrophy

On Xp21 region several genes such as adrenal hypoplasia congenita(AHC) gene, glycerol kinase (GK) gene and Duchenne muscular dystrophy(DMD) gene are located contiguously. If there is a long deletion in that region, various combination of genetic defect can be occurred from one kind of genetic defect to all three kinds of genetic defect simultaneously. In case of more than two genetic defects simultaneously, we call it contiguous gene deletion syndrome. The major clinical manifestations of the Xp21 contiguous gene deletion syndrome are sum of each diseases, electrolyte imbalance and hyperpigmentation for adrenal hypoplasia congenita, psychomotor retardation, letharginess and convulsion for glycerol kinase deficiency and muscle weakness and hypotonia for Duchenne muscular dystrophy. Goals of the treatment are control of each disorders, glucocorticoid and mineralocorticoid for adrenal hypoplasia congenita, low fat diet and prevention of fasting and hypercatabolic status for glycerol kinase deficiency and physiotherapy for Duchenne muscular dystrophy. In case of hyponatremia and hyperkalemia combined with hyperpigmentation, adrenal hypoplasia congenita could be suspected. In glycerol kinase deficiency, markedly elevated glycerol excretion can be detected on urine organic acid analysis by gaschromatography with mass spectrometry. On Duchenne muscular dystrophy, creatinine kinase is markedly elevated on chemistry. We report here first Korean case of Xp21 contiguous gene deletion syndrome of adrenal hypoplasia congenita, glycerol kinase deficiency and Duchenne muscular dystrophy.