Implementación de una metodología para la detección de marcadores bioquímicos en la tirosinemia tipo 1

Fundamento: la tirosinemia hereditaria tipo I o tirosinemia hepato-renal es una enfermedad autosómica recesiva causada por la deficiencia de la enzima fumarilacetoacetato hidrolasa. Debido a su complejidad metabólica, su confirmación lleva aparejado, un conjunto de métodos altamente costosos. Objetivo: implementar una metodología de trabajo para la detección de metabolitos marcadores de la tirosinemia tipo 1. Método: se realizó un estudio descriptivo y transversal en una serie de casos evaluados en el período comprendido entre enero del 2021 a febrero del 2023. Como examen inicial se realizaron las pruebas cualitativas de α nitroso beta naftol y 2,4 dinitrofenilhidracina para la identificación de la tirosina y los α cetoácidos respectivamente. Luego se realizó el método HPLC para la cuantificación de la tirosina y CG-EM para la determinación del perfil cromatográfico en orina como técnicas confirmatorias. Resultados las pruebas cualitativas resultaron positivas para la tirosina y sus metabolitos, así como, para los alfa cetoácidos. El perfil de ácidos orgánicos mostró excreción elevada de los metabolitos marcadores de la enfermedad en 8 casos, a los cuales se les fue realizada la cuantificación de la tirosina que resultaron positivos de padecer la enfermedad. Conclusiones: la implementación de la metodología resultó ser una herramienta valiosa en el diagnóstico temprano de la enfermedad.

Foundation: hereditary tyrosinemia type I or hepato-renal tyrosinemia is an autosomal recessive disease caused by deficiency of the enzyme fumarylacetoacetate hydrolase. Due to its metabolic complexity, its confirmation requires a set of highly expensive methods. Objective: to implement a work methodology for the detection of marker metabolites of type 1 tyrosinemia. Method: a descriptive and cross-sectional study was carried out in a series of cases evaluated in the period from January 2021 to February 2023. As an initial examination, qualitative tests of α nitroso beta naphthol and 2,4 dinitrophenylhydrazine were carried out for the identification of tyrosine and α keto acids respectively. Then, the HPLC method was performed for the quantification of tyrosine and GC-MS for the determination of the chromatographic profile in urine as confirmatory techniques. Results: qualitative tests were positive for tyrosine and its metabolites, as well as for alpha keto acids. The organic acid profile showed elevated excretion of the disease marker metabolites in 8 cases, in which tyrosine quantification was performed, which were positive for suffering from the disease. Conclusions: the implementation of the methodology turned out to be a valuable tool in the early diagnosis of the disease.

Variantes del gen GBA en el Suroccidente Colombiano / Variants of the GBA gene in the Southwest of Colombia

Introducción: La Enfermedad de Gaucher (EG) es un trastorno genético autosómico recesivo, causado por la deficiencia de la enzima B-Glucocerebrosidasa acida (GBA). En Colombia se ha estimado una prevalencia de 1:266.441 habitantes. Sin embargo, el país no cuenta con datos exactos sobre la incidencia, prevalencia y carga poblacional de esta enfermedad. Objetivo: Con el objetivo de caracterizar molecularmente las variantes encontradas en el gen GBA presentes en pacientes del Suroccidente Colombiano con enfermedad de Gaucher. Materiales y métodos: Se incluyeron 19 pacientes en el estudio, 57,8% de género masculino, con intérvalo de edad entre 4 y 71 años, diagnosticados clínica y enzimáticamente con EG. Se realizó un análisis molecular del gen GBA y posteriormente se buscaron las variantes en diferentes bases de datos poblacionales y clínicas; además se realizó análisis bioinformático para evaluar el posible impacto de las variantes de interés en la estructura y funcionalidad de la proteína. Resultados: Se encontraron 14/19 pacientes homocigotos; 4/19 heterocigotos compuestos y 1/19 heterocigotos). Se reportó la presencia de 7 variantes que codifican para 8 genotipos diferentes. El genotipo más frecuente es p.Asn409Ser/p.Asn409Ser (36%). De las 7 variantes encontradas, se reportó que específicamente p. Asn409Ser (10/23 alelos) y p.Leu483Pro (3/23 alelos) y p.Lys237Glu (3/23 alelos), están presentes en el 69,5% de los alelos. Todas las variantes presentaron una significancia clínica patogénica. Conclusiones: Este trabajo contribuye al establecimiento de las bases moleculares de la EG en los pacientes del Suroccidente Colombiano, permitiendo realizar una correlación genotipo-endotipo-fenotipo. Así mismo, se determina que los algoritmos de diagnóstico que incluyen análisis molecular y herramientas predictivas bioinformáticas permiten mejorar el diagnóstico, el tratamiento y el pronóstico de los pacientes afectados por EG, generando un impacto positivo en el seguimiento de los afectados, de la mano de una correcta consejería genética y estudios de portadores.

Introduction:Gaucher's disease (EG) is an autosomal recessive genetic disorder, caused by a deficiency of the acid B-Glucocerebrosidase (GBA) enzyme. In Colombia, a prevalence of 1: 266.441 inhabitants have been estimated. However, the country does not have exact data on the incidence, prevalence and population burden of this disease. Objective: molecularly characterize the variants found in the GBA gene present in patients from the Southwest of Colombia with Gaucher disease. Material and methods: 19 patients were included in the study, 57,8% male, with an age range between 4 and 71 years, clinically and enzymatically diagnosed with GD. A molecular analysis of the GBA gene was performed and the variants were subsequently searched in different population and clinical databases; In addition, a bioinformatic analysis was performed to evaluate the possible impact of the variants of interest on the structure and functionality of the protein. Results: 14/19 homozygous patients were found; 4/19 compound heterozygotes and 1/19 heterozygotes). The presence of 7 variants coding for 8 different genotypes was reported. The most frequent genotype was p.Asn409Ser/p.Asn409Ser (36%). Of the 7 variants found, it was reported that specifically p. Asn409Ser (10/23 alleles) and p.Leu483Pro (3/23 alleles) and p.Lys237Glu (3/23 alleles), are present in 69,5% of the alleles. All the variants presented a pathogenic clinical significance. Conclusion: This work contributes to the establishment of the molecular bases of GD in patients from the Southwest of Colombia, allowing a genotype-endotype-phenotype correlation to be carried out. Likewise, it is determined that diagnostic algorithms that include molecular analysis and bioinformatic predictive tools allow improving the diagnosis, treatment and prognosis of patients affected by GD, generating a positive impact on the follow-up of those affected, hand in hand with correct genetic counseling and carrier studies.

A case of atypical cholesterol side chain defect possibly caused by CYP11A1 heterozygous mutation / 中华内分泌代谢杂志

This paper reports a case of atypical cholesterol side chain enzyme deficiency caused possibly by CYP11A1p.A359V heterozygous mutation. The patient was diagnosed as congenital adrenal hyperplasia because he was born with gonadal dysplasia and there were manifestations of salt losing and pigment changing, combined with high level of plasma ACTH. Further genetic screening revealed CYP11A1p.A359V heterozygous mutations in patients with a final diagnosis of cholesterol side chain enzyme deficiency which was treated effectively to glucocorticoid.

RBC Enzyme Analysis / 임상소아혈액종양

Among ~20 RBC enzyme deficiencies causing hereditary hemolytic anemia (HRA), deficiencies involving three RBC enzymes such as glucose-6-phosphatase, pyruvate kinase and pyrimidine 5'-nucleodiase were known to be relatively common. The methods that have been used for RBC enzyme analysis are based on the kinetic spectrophotometry. This method, however, usually requires multiple step reactions and manual manipulations which are labor-intensive and time-consuming, and carry a greater risk of error due to their complexity. To solve this problem, we had successfully developed the multiplex enzyme analysis for galactose using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). We are now trying to adopt this method to other RBC enzymes associated with HRA. The devised method will allow simple, rapid, sensitive and reproducible quantification of RBC enzymes and should be helpful for the confirmatory diagnosis of HRA caused by RBC enzyme deficiencies.

RBC Enzyme Analysis / 임상소아혈액종양

Among ~20 RBC enzyme deficiencies causing hereditary hemolytic anemia (HRA), deficiencies involving three RBC enzymes such as glucose-6-phosphatase, pyruvate kinase and pyrimidine 5'-nucleodiase were known to be relatively common. The methods that have been used for RBC enzyme analysis are based on the kinetic spectrophotometry. This method, however, usually requires multiple step reactions and manual manipulations which are labor-intensive and time-consuming, and carry a greater risk of error due to their complexity. To solve this problem, we had successfully developed the multiplex enzyme analysis for galactose using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). We are now trying to adopt this method to other RBC enzymes associated with HRA. The devised method will allow simple, rapid, sensitive and reproducible quantification of RBC enzymes and should be helpful for the confirmatory diagnosis of HRA caused by RBC enzyme deficiencies.

Red Blood Cell Enzymopathies Causing Hereditary Hemolytic Anemia / 임상소아혈액종양

The RBC enzyme deficiencies causing hereditary hemolytic anemia (HHA) can be divided into three groups: those participating in the glycolytic (E-M) pathway; those involved with the maintenance of a high ratio of reduced to oxidized glutathione; one enzyme in the nucleotide degradation and salvage pathway. Although RBC enzyme deficiencies causing HHA are rare, 3 of the 15 kinds of important and relatively frequently reported enzyme deficiencies such as pyruvate kinase, glucose-6-phosphate-dehydrogenase and pyrimidine-5'-nucleotidase deficiencies are briefly reviewed. The molecular genetics, clinical symptoms, diagnosis and therapeutic approaches of each enzyme deficiencies are summerized. As these enzyme deficiencies are reported throughout the world as well as in Korea with the identification of the mutations, considering a broad spectrum of etiologies for the diagnosis of HHA seems to be warranted.

Red Blood Cell Enzymopathies Causing Hereditary Hemolytic Anemia / 임상소아혈액종양

The RBC enzyme deficiencies causing hereditary hemolytic anemia (HHA) can be divided into three groups: those participating in the glycolytic (E-M) pathway; those involved with the maintenance of a high ratio of reduced to oxidized glutathione; one enzyme in the nucleotide degradation and salvage pathway. Although RBC enzyme deficiencies causing HHA are rare, 3 of the 15 kinds of important and relatively frequently reported enzyme deficiencies such as pyruvate kinase, glucose-6-phosphate-dehydrogenase and pyrimidine-5'-nucleotidase deficiencies are briefly reviewed. The molecular genetics, clinical symptoms, diagnosis and therapeutic approaches of each enzyme deficiencies are summerized. As these enzyme deficiencies are reported throughout the world as well as in Korea with the identification of the mutations, considering a broad spectrum of etiologies for the diagnosis of HHA seems to be warranted.

Normalization of Red Cell Enolase Level Following Allogeneic Bone Marrow Transplantation in a Child with Diamond-Blackfan Anemia

We describe a girl with Diamond-Blackfan anemia with accompanying red cell enolase deficiency. At the age of 9 yr old, the patient received allogeneic bone marrow transplantation from her HLA-identical sister who had normal red cell enolase activity. While the post transplant DNA analysis with short tandem repeat has continuously demonstrated a stable mixed chimerism on follow-up, the patient remains transfusion independent and continues to show a steady increase in red cell enolase activity for over two and a half years following bone marrow transplantation.

Treatment and management of patients with inherited metabolic diseases / 소아과

Inherited metabolic disease is rare disorders that show symptoms mainly in pediatric age and early treatment is important for preventing complications of the disease. Recent development in molecular and biochemical techniques help clinicians with proper diagnosis of patients, however, many of the disease still remain lack of effective therapeutic strategies. Better understanding on biochemical and molecular basis of pathogenesis of the disease combined with advanced medical care would provide new sight on the disease that can also improve the quality of life and long-term prognosis of patients. Traditionally, there are several modalities in the treatment of metabolic diseases depend on the biochemical basis of the disease such as diet restriction, removing or blocking the production of toxic metabolites, and stimulating residual enzyme activity. The inherited metabolic disease is not familiar for many clinicians because the diagnosis is troublesome, treatment is complicated and prognosis may not as good as expected in other diseases. Recently, new therapeutic regimens have been introduced that can significantly improve the medical care of patients with metabolic disease. Enzyme replacement therapy has showed promising efficacy for lysosomal storage disease, bone marrow transplantation is effective in some disease and gene therapy has been trying for different diseases. The new trials for treatment of the disease will give us promising insight on the disease and most clinicians should have more interest in medical progress of the metabolic disease.