Mucopolysaccharidosis type VII (Sly syndrome) - What do we know?

Mucopolysaccharidosis type VII (MPS VII) is an ultra-rare, life-threatening, progressive disease caused by genetic mutations that affect lysosomal storage/function. MPS VII has an estimated prevalence of <1:1,000,000 and accounts for <3% of all MPS diagnoses. Given the rarity of MPS VII, comprehensive information on the disease is limited and we present a review of the current understanding. In MPS VII, intracellular glycosaminoglycans accumulate due to a deficiency in the lysosomal enzyme that is responsible for their degradation, ß-glucuronidase, which is encoded by the GUSB gene. MPS VII has a heterogeneous presentation. Features can manifest across multiple systems and can vary in severity, age of onset and progression. The single most distinguishing clinical feature of MPS VII is non-immune hydrops fetalis (NIHF), which presents during pregnancy. MPS VII usually presents within one month of life and become more prominent at 3 to 4 years of age; key features are skeletal deformities, hepatosplenomegaly, coarse facies, and cognitive impairment, although phenotypic variation is a hallmark. Current treatments include hematopoietic stem cell transplantation and enzyme replacement therapy with vestronidase alfa. Care should be individualized for each patient. Development of consensus guidelines for MPS VII management and treatment is needed, as consolidation of expert knowledge and experience (for example, through the MPS VII Disease Monitoring Program) may provide a significant positive impact to patients.

Evaluation of newborn screening in the state of Mato Grosso from 2005 to 2019 / Avaliação da triagem neonatal no Estado de Mato Grosso no período de 2005 a 2019

ABSTRACT Objective: To evaluate quality indicators of the Neonatal Screening Referral Service of the state of Mato Grosso (NSRS-MT) from 2005 to 2019. Methods: Cross-sectional, retrospective, exploratory, descriptive, and observational study from 2005 to 2019. The following parameters were analyzed: age of newborns at the first collection, time between sample collection and arrival at the laboratory, time between the arrival and release of results and time between requesting the second sample and arrival at the NSRS. The population coverage of the program and the incidence of each clinical situation screened were also analyzed. Results: NSRS-MT coverage was analyzed and recorded as 76%. The incidence was analyzed for congenital hypothyroidism (CH) 1:1867, phenylketonuria (PKU) 1:33,311, sickle cell disease (SCD) 1:2004, cystic fibrosis (CF) 1:12,663, congenital adrenal hyperplasia (CAH) 1:15,843, and biotinidase deficiency (DB) 1:25,349. The median age (days) at the first consultation was: 44 for HC, 22 for PKU, 60 for DF, 52 for FC, 79 for HAC and 79 for DB. The mean time between exam collection and delivery to the NSRS was 8.4 days; between the arrival and release of results, 9 days; and for the return of recalls, 59 days. Conclusions: Regarding the coverage of the target population and collection at the ideal age, the NSRS-MT presents values below the national average. However, regarding the mean age at the time of the first consultation, the state's performance is better than the national.

RESUMO Objetivo: Avaliar indicadores de qualidade do Serviço de Referência em Triagem Neonatal do Estado de Mato Grosso (SRTN/MT) no período de 2005 a 2019. Métodos: Estudo transversal, retrospectivo, exploratório, descritivo e observacional, que utilizou dados do formulário FormSUS nos anos de 2005 a 2019. Foram analisados os seguintes parâmetros: idade dos recém-nascidos na primeira coleta, tempo entre coleta da amostra e chegada ao laboratório, tempo entre a chegada e a liberação dos resultados e tempo entre a solicitação da segunda amostra até a chegada ao SRTN. Foram analisadas, também, a cobertura populacional do programa e a incidência de cada situação clínica triada. Resultados: Cobertura do SRTN-MT: 76%. Incidências: hipotireoidismo congênito (HC) 1:1.867, fenilcetonúria (PKU) 1:33.311, doença falciforme (DF) 1:2.004, fibrose cística (FC) 1:12.663, hiperplasia adrenal congênita (HAC) 1:15.843 e deficiência de biotinidase (DB) 1:25.349. A mediana da idade (dias) na primeira consulta foi: 44 para HC, 22 para PKU, 60 para DF, 52 para FC, 79 para HAC e 79 para DB. A média entre a coleta do exame e a entrega no SRTN foi de 8,4 dias; entre a chegada e liberação dos resultados, de 9 dias; e para o retorno de reconvocados, de 59 dias. Conclusões: Com relação à cobertura da população alvo e a coleta na idade ideal, o SRTN apresenta valores abaixo da média nacional. Contudo, quanto à idade média no momento da primeira consulta, o desempenho de MT é melhor que a média nacional.

Hipoglicemia hipocetósica por deficiencia de carnitina en un niño

Durante el ayuno, la oxidación de ácidos grasos y la formación de cuerpos cetónicos son necesarios para la producción de energía. La carnitina es esencial para que los ácidos grasos de cadena larga se transfieran a la mitocondria para la oxidación de ácidos grasos. La deficiencia primaria de carnitina es un defecto recesivo que se expresa con un espectro clínico amplio que incluye descompensación metabólica, hipoglicemia hipocetósica o cardiomiopatía en la niñez, fatigabilidad en la adultez o ausencia de síntomas. En nuestro país no hay publicaciones sobre el tema, por lo que en el presente artículo se reporta el caso de un niño que presentó una deficiencia de carnitina expresada como hipoglicemia hipocetósica y se analiza sus hallazgos clínicos, bioquímicos e histopatológicos.

During fasting, the oxidation of fatty acids and the formation of ketone bodies are necessary for energy production. Carnitine is essential for long-chain fatty acids to be transferred to the mitochondria for fatty acid oxidation. Primary carnitine deficiency is a recessive defect that is expressed with a broad clinical spectrum that includes metabolic decompensation, hypoketotic hypoglycemia or cardiomyopathy in childhood, fatiguability in adulthood or absence of symptoms. In our country there are no publications on the subject, so this article reports the case of a child who had carnitine deficiency expressed as hypoketotic hypoglycemia and its clinical, biochemical and histopathological findings are analyzed.

Lethal mitochondrial trifunctional protein deficiency caused by HADHB gene variation: a case report / 中华围产医学杂志

This article reported a male neonate with lethal mitochondrial trifunctional protein deficiency (MTPD) caused by compound heterozygous variations in the HADHB gene. The patient presented with poor milk intake complicated by abnormal myocardial enzymes within 24 h after birth and was transferred to the Children's Hospital of Nanjing Medical University on day 4. Physical examination revealed no obvious abnormalities on admission. Laboratory examination showed increased creatine kinase isoenzyme and cardiac troponin levels, and electrocardiogram suggested sinus tachycardia and low QRS voltage in limb leads. Blood screening for metabolic abnormalities showed high levels of tetradecenyl carnitine and various 3-hydroxycarnitines. Heterozygous mutations of c.739C>T(p.Arg247Cys) and c.607C>T(p.Arg203Ter,272) were detected in the HADHB gene in the boy, which were pathogenic variants included in the Human Gene Mutation Database. Followed up to three months of age, the boy was readmitted to hospital due to poor milk intake for one week and poor response for 2 d after catching a cold. After admission, he quickly developed multiple organs dysfunction such as heart failure and respiratory failure, and then died. Lethal MTPD is rare with no effective treatment and poor prognosis. Lethal MTPD should be highly suspected when unexplained cardiomyopathy, hypoglycemia, acidosis and other metabolic abnormalities appear in the neonatal period, and an early diagnosis could be confirmed with genetic testing in the neonatal period.

Clinical experience with orphan drugs for rare metabolic diseases.

INTRODUCTION: Inborn errors of metabolism are a highly heterogeneous group of orphan diseases. Diet therapy and enzyme and coenzyme replacement are the most frequently used treatment. There are few patients and published studies about inborn errors of metabolism. The main objective of this study was to describe the effectiveness of orphan drugs in inborn errors of metabolism in paediatric patients. MATERIAL AND METHODS: Retrospective descriptive study of 24 months on patients diagnosed with inborn errors of metabolism during childhood and who attended the pharmacy clinic or Day-Care Unit of a 630-bed general hospital. RESULTS: The study included 15 patients with a median age of 17.8 years and were treated with nine different drugs: sapropterin, sodium phenylbutyrate, miglustat, velaglucerase, sebelipase, idursulfase, 5-hydroxytryptophan, succinate, and riboflavin. Seven different inborn errors of metabolism were observed: phenylketonuria, defects of the urea cycle, Gaucher, Nieman-Pick, Hunter's disease, along with acid lipase deficiency, and mitochondrial diseases. Orphan drugs used for the treatment of inborn errors of metabolism accounted for 1.3% of hospital drug costs. Some orphan drugs achieved asymptomatic patients, but others just produced a modest symptomatic improvement. Most patients showed good tolerance to the treatment. CONCLUSIONS: Orphan drugs used in inborn errors of metabolism had an easy to manage toxicity profile, with many disparities in effectiveness. These drugs have a high economic impact. The cost-effectiveness ratio for orphan drugs is a controversial issue due to their high cost and the inconclusive clinical evidence.

Experiencia clínica con medicamentos huérfanos para enfermedades raras metabólicas / Clinical experience with orphan drugs for rare metabolic diseases

Introducción: Los errores congénitos del metabolismo son un grupo muy heterogéneo de enfermedades raras. La mayoría se pueden tratar con dieta y sustitución enzimática. Existen pocos pacientes y pocos estudios publicados en estas enfermedades. Por ello, se ha llevado a cabo un estudio con el objetivo de evaluar la efectividad de los medicamentos huérfanos utilizados en errores congénitos del metabolismo de un hospital general de 630 camas. Material y métodos: Estudio descriptivo restrospectivo de 24 meses de duración en un hospital general de 630 camas. Se incluyeron los pacientes diagnosticados durante la infancia de errores congénitos del metabolismo y que acudieron a Hospital de Día o a la consulta de Farmacia.(AU)

Introduction: Inborn errors of metabolism are a highly heterogeneous group of orphan diseases. Diet therapy and enzyme and coenzyme replacement are the most frequently used treatment. There are few patients and published studies about inborn errors of metabolism. The main objective of this study was to describe the effectiveness of orphan drugs in inborn errors of metabolism in paediatric patients. Material and Methods: Retrospective descriptive study of 24 months on patients diagnosed with inborn errors of metabolism during childhood and who attended the pharmacy clinic or Day-Care Unit of a 630-bed general hospital. (AU)

A case of prolidase deficiency in a male patient.

Prolidase deficiency is an extremely rare, autosomal recessive disorder resulting in defective collagen formation. We report a case of prolidase deficiency in a male child, highlighting the dermatologic features. Early diagnosis is important as these patients encounter significant multisystem comorbidities requiring multispecialty care.

Usher syndrome with methylmalonic acidemia and homocysteine in an infant / 中华围产医学杂志

A case of Usher syndrome with methylmalonic acidemia and homocysteine is reported. The patient was a two-month-old and small for gestational age male infant hospitalized for "feeding difficulties" during the neonatal period. The baby boy presented hypotonia, microcephaly, and hearing loss after birth. Genetic test found compound heterozygous mutations of c.482G>A and c.567dup in MMACHC, and both were pathogenic mutations inherited from his parents. Moreover, the patient also had compound heterozygous variants at c.2802T>G and c.14017T>C of USH2A gene. The former was suspected to be pathogenic, and the latter was of unknown clinical significance. Both were from the parents. Usher syndrome and methylmalonic acidemia with homocysteine were clinically diagnosed. Followed up to the age of two, the child was found with moderate mental retardation, while the physical development was comparable to that of the same age group.

Application of proteomics technology in diagnosis and pathogenesis of genetic metabolic diseases / 中华检验医学杂志

Inborn Errors of Metabolism (IEM) are diseases caused by genetic defects in the biosynthesis of certain enzymes, receptors, carriers and membrane pumps composed of peptides and/or proteins necessary to maintain normal metabolism of the body, namely, mutations in the genes encoding such peptides (proteins). Through metabolomic analysis of sugars, amino acids, organic acids, fatty acids, carnitine and other substances in blood or urine, as well as cellular enzymology, molecular biology and proteomics analysis. We can identify and quantify abnormal biomarks, determine biomarkers as diagnostic and therapeutic monitoring tools. At the same time, through proteomic research. We can provide scientific basis for the pathogenesis of hereditary metabolic diseases.

Neoseq for neonatal screening of fatty acid oxidation disorders / 中华围产医学杂志

Objective:To explore the value of Neoseq in screening and diagnosis of neonatal fatty acid oxidation disorders (FAOD).Methods:A retrospective case-control study was conducted on 163 500 live births in Changzhou city from April 2015 to April 2021. The following two models were adopted for FAOD screening and diagnosis. (1) Traditional mode: Heel blood samples were obtained from all subjects for initial screening using tandem mass spectrum (TMS), followed by next-generation sequencing (NGS) and other differential diagnostic testings for those with positive results. (2) Neoseq: Neoseq was performed on the true positive, negative and false positive cases according to the traditional mode screening results. The detection rate, additional discovery, reporting period, and other parameters of the two models for FAOD were described and compared.Results:(1) Detection and diagnosis of FAOD: A total of 18 confirmed cases of FAOD were detected through the traditional model, with an incidence of 1/9 083 in Changzhou city. The positive rate was 0.55% (907/163 500) for initial TMS and 0.04% (73/163 500) for the second. The positive predictive value was 2.0%(18/907), with a false positive rate of 98%(889/907) in the initial screening. (2) The results of Neoseq: ①Pathogenic mutations were detected in 16 of the 18 confirmed cases, and the coincidence rate of mutation sites between the two methods was 16/18. The other two confirmed cases were missed diagnosed by Neoseq, including one β-ketothiolase deficiency with only one detected pathogenic mutation and one medium-chain acyl-CoA dehydrogenase deficiency without any detected pathogenic mutation. ②No pathogenic mutations were detected in the 57 false-positive cases by Neoseq. ③Among the 100 negative cases in initial screening, DUOX2 heterozygous mutation, and MTTL1 hemizygous mutation were detected in one case each. ④The median period of results reporting was 43.5 d (28-104 d) for the traditional mode and 12 d (10-15 d) for the Neoseq mode. Conclusions:Neoseq has a high detection rate for FAOD. Combined with TMS screening, Neoseq reduces the false-positive rate of biochemical screening, rapidly identifies genetic causes by shortening the results waiting time and covers diseases that couldn't be detected by traditional biochemical methods.

Phenotype and genotype analysis of 6 patients with 21-hydroxylase deficiency / 中华全科医师杂志

The clinical data of 6 patients with 21-hydroxylase deficiency(21-OHD) diagnosed in The People′s Hospital of Xinjiang Uygur Autonomous Region from 2015 to 2020 were retrospectively analyzed. There were 2 male cases manifesting shorter height, high progesterone level and infertility. And 4 cases were females, manifesting primary amenorrhea, heterosexual precocious puberty, fatigue during emergency, decreased physical strength, dark skin, clitoral hypertrophy and vulva fusion. None of the parents had a history of consanguinity. All but one patient received glucocorticoid replacement therapy. The sequencing of exons and introns of 21CYPA2 gene showed tuat 1 case was homozygous mutation and 5 cases were complex heterozygous mutation. In terms of clinical phenotype, 1 case was non-classical (complex heterozygous mutation) and 5 cases were simple virilizing phenotype.

Distinctive Features of Hepatic Steatosis in Children: Is It Primary or Secondary to Inborn Errors of Metabolism?

PURPOSE: The incidence of hepatic steatosis among children has been increasing; however, data distinguishing simple steatosis from a more complex disorder are lacking. METHODS: This study identified the etiologies resulting in hepatic steatosis through a retrospective review of pediatric liver biopsies performed in the last 10 years. A total of 158 patients with hepatic steatosis proven by histopathological evaluation were enrolled in the study, and baseline demographic features, anthropometric measurements, physical examination findings, laboratory data, ultrasonographic findings, and liver histopathologies were noted. RESULTS: The two most common diagnoses were inborn errors of metabolism (IEM) (52.5%) and nonalcoholic fatty liver disease/steatohepatitis (NAFLD/NASH) (29.7%). The three most common diseases in the IEM group were glycogen storage disorders, Wilson's disease, and mitochondrial disease. The rates of consanguineous marriage (75.6%; odds ratio [OR], 26.040) and positive family history (26.5%; OR, 8.115) were significantly higher (p=0.002, p<0.001, respectively) in the IEM group than those in the NAFLD/NASH group. Younger age (p=0.001), normal anthropometric measurements (p=0.03), increased aspartate aminotransferase levels (p<0.001), triglyceride levels (p=0.001), and cholestatic biochemical parameters with disrupted liver function tests, as well as severe liver destruction of hepatic architecture, cholestasis, fibrosis, and nodule formation, were also common in the IEM group. CONCLUSION: Parents with consanguinity and positive family history, together with clinical and biochemical findings, may provide a high index of suspicion for IEM to distinguish primary steatosis from the consequence of a more complex disorder.

Screening and follow-up results of fatty acid oxidative metabolism disorders in 608 818 newborns in Jining, Shandong province.

To investigate the incidence and gene mutation characteristics of fatty acid oxidative metabolism disorders in Jining area of Shandong province , and to evaluate the therapeutic effect. Blood samples of newborns were collected in Jining of Shandong province between July 14, 2014 and December 31, 2019. Tandem mass spectrometry was used to determine the levels of carnitine and acylcarnitine in the blood to screen for fatty acid oxidative metabolism disorder. For newborns with positive screening result, blood DNA was analyzed by MassARRAY and high-throughput sequencing, then verified by Sanger sequencing. The diagnosed children were given early intervention and treatment, and followed up. Forty-two children with fatty acid oxidative metabolism disorders were screened out of 608 818 newborns, with an incidence rate of 1/14 496. Primary carnitine deficiency (16 cases, 38.10%) and short-chain acyl-CoA dehydrogenase deficiency (16 cases, 38.10%) were the most common, followed by very long-chain acyl-CoA dehydrogenase deficiency (6 cases, 14.29%), medium-chain acyl-CoA dehydrogenase deficiency (4 cases, 9.53%). In children with primary carnitine deficiency, c.1400C>G (p.S467C) and c.51C>G were the most common in mutations; and c.278C>T (p.S93L), c.1049T >C (p.L350P), c.572A>G (p.K191R), c.431T>C (p.L144P) were newly discovered mutations. Ten children with carnitine replacement therapy showed normal development during the follow-up. In 6 children without carnitine replacement treatment, hypoglycemia developed during the neonatal period in 1 case, in whom the creatine kinase was increased, and the intellectual and language development delayed in the later period; the other 5 children developed normally during the follow-up period. The gene mutations c.1031A>G (p.E344G) and c.164C>T (p.P55L) were common in children with short-chain acyl-CoA dehydrogenase deficiency, and the children developed normally during the follow-up. In children with very long-chain acyl-CoA dehydrogenase deficiency, the c.1349G>A was common in gene mutations; and c.488T>A , c.1228G>T (p.D410Y), c.1276G>A (p.A426T), c.1522C>T (p.Q508*), c.1226C>T (p.T409M) were newly discovered mutations. Three children treated with milk powder rich in medium-chain fatty acids had normal development during the follow-up. The other 3 cases with combined carnitine reduction were treated with levocarnitine and milk powder enriched of medium-chain fatty acids, 1 case developed normally during the follow-up, 1 case died of acute illness at the age of and 1 case had acute illness and recovered after treatment, and developed normally during the follow-up. c.449_452del (p.T150Rfs*4) was the most common gene mutation in children with medium-chain acyl-CoA dehydrogenase deficiency, and c. 718A>G (p.M240V) was a newly discovered mutation. All children received low-fat diet, and hunger and fatigue were avoided; 1 child was supplemented with L-carnitine, and the other 3 children were not treated with drugs, and all of them developed normal during the follow-up. Primary carnitine deficiency and short-chain acyl-CoA dehydrogenase deficiency are the most common fatty acid oxidative metabolism disorders in Jining area. There are gene hotspot mutations and new discovered gene mutations in patients. Patients with early diagnosis and treatment through neonatal screening have a good prognosis.

Screening for neonatal inherited metabolic disorders by tandem mass spectrometry in Guangzhou.

To analyze the screening results for inherited metabolic disorders (IMD) in newborns by tandem mass spectrometry (MS/MS) in Guangzhou.A total of 272 117 newborns in Guangzhou from Jan 2015 to Dec 2020 were screened for IMD by MS/MS in Guangzhou Newborn Screening Center. When the primary screening was positive, the newborns and their mothers were recalled. For those with positive in re-examination, the biochemical and related genetic analysis were required for confirmation. The screening results, clinical characteristics and outcomes of the confirmed cases were retrospectively analyzed and the performance was optimized. Among 272 117 neonates, 1808 (0.66%) cases were positive in primary screening, and 1738 cases (96.13%) were recalled for review. The median clinical diagnosis time was 15 d after birth. A total of 79 cases of IMD were diagnosed, including 23 with aminoacidopathy, 17 with disorder of organic acid metabolism and 39 with fatty acid oxidation disorders, involving 21 diseases. The incidence rate was 1/3444 in newborns, and the positive predictive value of 4.5%. Four false negative cases were found, all of them were citrin deficiency. The common diseases were primary carnitine deficiency (26.6%), methylmalonic aciduria (12.7%) and phenylalanine hydroxylase deficiency (11.4%). The mothers of 32 cases were confirmed, including 30 cases of primary carnitine deficiency, 1 case of isobutyl-coenzyme A dehydrogenase deficiency and 1 case of 3-methylcromaryl coenzyme A carboxylase deficiency. The detection rate was 1/2451 in total population. During the follow-up, most patients remain asymptomatic, except for 5 severe cases who died early (1 case of maple syrup urine disease, 2 cases of isolated methylmalonic acidurmia, and 2 cases of carnitine-acylcarnitine translocase deficiency); and 10 cases of organic acid metabolism disorders developed mild psychomotor developmental retardation. After optimizing the screening indicators, the number of initial screening positives dropped to 903, and the positive predictive value increased to 9.1%, and no confirmed cases were missed. The incidence rate of fatty acid oxidation disorders is high in Guangzhou. A variety of IMD can be effectively screened out by MS/MS, and the screening performance can be improved by optimizing screening indicators.

Extended Phenotyping and Functional Validation Facilitate Diagnosis of a Complex Patient Harboring Genetic Variants in MCCC1 and GNB5 Causing Overlapping Phenotypes.

Identifying multiple ultra-rare genetic syndromes with overlapping phenotypes is a diagnostic conundrum in clinical genetics. This study investigated the pathogenicity of a homozygous missense variant in GNB5 (GNB5L; NM_016194.4: c.920T > G (p. Leu307Arg); GNB5S; NM_006578.4: c.794T > G (p. Leu265Arg)) identified through exome sequencing in a female child who also had 3-methylcrotonyl-CoA carboxylase (3-MCC) deficiency (newborn screening positive) and hemoglobin E trait. The proband presented with early-onset intellectual disability, the severity of which was more in keeping with GNB5-related disorder than 3-MCC deficiency. She later developed bradycardia and cardiac arrest, and upon re-phenotyping showed cone photo-transduction recovery deficit, all known only to GNB5-related disorders. Patient-derived fibroblast assays showed preserved GNB5S expression, but bioluminescence resonance energy transfer assay showed abolished function of the variant reconstituted Gß5S containing RGS complexes for deactivation of D2 dopamine receptor activity, confirming variant pathogenicity. This study highlights the need for precise phenotyping and functional assays to facilitate variant classification and clinical diagnosis in patients with complex medical conditions.

Desensibilización con idursulfase en un niño con síndrome de Hunter (mucopolisacaridosis II) / Idursulfase desensitization in a child with Hunter syndrome (mucopolysaccharidosis ii)

La terapia de reemplazo enzimático disminuye la morbilidad y mejora la calidad de vida de los pacientes con mucopolisacaridosisii. Se han descrito reacciones de hipersensibilidad inmediata a este fármaco. La desensibilización es un tratamiento que induce la tolerancia temporaria a una droga y permite al paciente alérgico recibir la medicación.Se presenta el caso de un niño de 7 años con diagnóstico de síndrome de Hunter que, luego de 4 años de tratamiento con idursulfase, tuvo dos episodios de anafilaxia durante la infusión del fármaco. Se detectó inmunoglubulina E específica mediante pruebas cutáneas, y fue positiva la intradermorreacción con dilución 1/10 (0,2 mg/ml). Se realizó un protocolo de desensibilización de 12 pasos, sin presentar eventos adversos. La evaluación alergológica y la posibilidad de desensibilización constituyeron herramientas útiles en el manejo de nuestro paciente

Enzyme replacement therapy with idursulfase decreases morbidity and improves quality of life of patients with mucopolysaccharidosis ii. Immediate hypersensitivity reactions to this drug have been described. Desensitization is a treatment that induces temporary tolerance to a culprit drug, allowing the allergic patient to receive the medication.We present the case of a 7-year-old patient diagnosed with Hunter syndrome who presented, after 4 years of treatment, two episodes of anaphylaxis during the infusion of idursulfase. Detection of specific immunoglobulin E was carried out using skin tests, with intradermal reaction at a 1/10 dilution (0.2 mg/ml) being positive. A 12-step desensitization protocol was performed without presenting adverse events.The allergological evaluation and the possibility of desensitization were useful tools in the management of our patient.

[Cost-effectiveness methods of newborn screening assessment.] / Métodos para la evaluación económica de programas de cribado neonatal.

Newborn screening programs are a fundamental tool for secondary prevention or pre-symptomatic detection of certain conditions. The implementation of a newborn screening program requires an evaluation of effectiveness, safety, cost-effectiveness, feasibility and budget impact. Economic evaluation aims to contribute to the sustainability and solvency of health systems, especially when it comes to informing about financing health interventions with public funds. This funding must be justified on the basis of robust evidence of effectiveness, safety, cost-effectiveness, and acceptability. One of the most important limitations when evaluating the cost-effectiveness of a newborn screening program for hereditary disorders or congenital errors of metabolism is the scarcity of scientific evidence that limits the robustness of the economic analysis. Given the low availability of data, the use of expert opinion as a data source is unavoidable to complete the information. However, two main problems make it difficult to synthesize data obtained from various sources: biases and heterogeneity. Moreover, the measurement of quality-adjusted life years (QALYs) in pediatric populations poses serious methodological challenges. In Spain, although there is some heterogeneity in the supply of newborn screening programs between regions, guidelines are being established based on the best available scientific evidence to achieve the homogenization of newborn screening policies and programs at national level.

Los programas de cribado neonatal son una herramienta fundamental para la prevención secundaria o detección presintomática de determinadas afecciones. La implantación de un programa de cribado neonatal requiere necesariamente de una evaluación de su efectividad, seguridad, coste-efectividad, factibilidad e impacto presupuestario. La evaluación económica pretende contribuir a la sostenibilidad y solvencia de los sistemas sanitarios, especialmente a la hora de informar sobre la posible financiación, con fondos públicos, de intervenciones sanitarias como el cribado poblacional. Esta financiación debe justificarse en base a pruebas robustas de efectividad, seguridad, coste-efectividad y aceptabilidad. Una de las limitaciones más importantes a la hora de evaluar el coste-efectividad de un programa de cribado neonatal de trastornos hereditarios o de errores congénitos del metabolismo es la escasez de evidencia científica que limita la solidez y robustez del análisis de evaluación económica. Dada la baja disponibilidad de datos, el uso de la opinión de expertos como fuente de datos es inevitable para completar la información necesaria. Sin embargo, dos problemas principales dificultan la síntesis de datos obtenidos de varias fuentes: sesgos y heterogeneidad. Por otro lado, la medición de los años de vida ajustados por calidad (AVAC) en poblaciones pediátricas plantea serios desafíos metodológicos en un análisis de evaluación económica. En España, aunque existe cierta heterogeneidad en la oferta de programas de cribado neonatal entre CC.AA., se están estableciendo directrices basadas en la mejor evidencia científica disponible para conseguir la homogeneización de políticas y programas de cribado neonatal a nivel nacional.

[Idursulfase desensitization in a child with Hunter syndrome (mucopolysaccharidosis II)]. / Desensibilización con idursulfase en un niño con síndrome de Hunter (mucopolisacaridosis II).

Enzyme replacement therapy with idursulfase decreases morbidity and improves quality of life of patients with mucopolysaccharidosis ii. Immediate hypersensitivity reactions to this drug have been described. Desensitization is a treatment that induces temporary tolerance to a culprit drug, allowing the allergic patient to receive the medication. We present the case of a 7-year-old patient diagnosed with Hunter syndrome who presented, after 4 years of treatment, two episodes of anaphylaxis during the infusion of idursulfase. Detection of specific immunoglobulin E was carried out using skin tests, with intradermal reaction at a 1/10 dilution (0.2 mg/ml) being positive. A 12-step desensitization protocol was performed without presenting adverse events. The allergological evaluation and the possibility of desensitization were useful tools in the management of our patient.

La terapia de reemplazo enzimático disminuye la morbilidad y mejora la calidad de vida de los pacientes con mucopolisacaridosis ii. Se han descrito reacciones de hipersensibilidad inmediata a este fármaco. La desensibilización es un tratamiento que induce la tolerancia temporaria a una droga y permite al paciente alérgico recibir la medicación. Se presenta el caso de un niño de 7 años con diagnóstico de síndrome de Hunter que, luego de 4 años de tratamiento con idursulfase, tuvo dos episodios de anafilaxia durante la infusión del fármaco. Se detectó inmunoglubulina E específica mediante pruebas cutáneas, y fue positiva la intradermorreacción con dilución 1/10 (0,2 mg/ml). Se realizó un protocolo de desensibilización de 12 pasos, sin presentar eventos adversos. La evaluación alergológica y la posibilidad de desensibilización constituyeron herramientas útiles en el manejo de nuestro paciente.

A case of methylmalonic acidemia and homocysteinemia cblX type with negative tandem mass spectrometry testing.

A child with methylmalonic acidemia and homocysteinemia cblX type presented focal seizures and epileptic spasms in early infancy, but the tandem mass spectrometry tests showed negative results during neonatal screening or acute attack. Despite treated with a variety of antiepileptic drugs, the child died at age of The blood spot sample of the patient was retrospectively tested with ultrahigh performance liquid chromatography-tandem mass spectrometry, and the increased levels of methylmalonic acid and homocysteine were revealed. Whole exome sequencing showed that the proband had a c.202C>G(p.Q68E) hemizygous mutation in gene, which was inherited from his mother.

Mucopolysacaridosis type iiib misdiagnosed as an autistic spectrum disorder: a case report and literature review / Mucopolissacaridose tipo iii b mal diagnosticada como transtorno de espectro autista: relato de caso e revisão de literatura

ABSTRACT Objective: To report a rare case of mucopolysaccharidosis IIIB in a pediatric patient, with emphasis on the description of the clinical manifestations and the early diagnosis. Case description: A 14-year-old male patient, who presented regression of neuropsychomotor development since his three years and six months old, with speech loss and frequent falls, evolving with behavioral changes, with agitation and aggressiveness. Although being diagnosed with autism, there was no response to the established treatment; he was subsequently submitted to metabolic investigation, which lead to the diagnosis of Mucopolysaccharidosis IIIB. Comments: Identifying a metabolic disorder requires connecting multiple signs and symptoms, as well as eliminating other apparent causes. MPS IIIB is a diagnostic challenge, particularly in the early stages and in the absence of a family history of the disease.

RESUMO Objetivo: Relatar o caso raro de um paciente pediátrico com mucopolissacaridose III B, com ênfase na descrição de manifestações clínicas. Descrição do caso: Paciente masculino de 14 anos que, a partir dos 3 anos e 6 meses de idade, apresentou regressão do desenvolvimento neuropsicomotor, com perda da fala e quedas frequentes, evoluindo com alterações comportamentais, agitação e agressividade. Diagnosticado como autista, não obteve resposta ao tratamento estabelecido, sendo posteriormente submetido à investigação metabólica, que evidenciou o diagnóstico de mucopolissacaridose III B. Comentários: A identificação de um distúrbio metabólico exige conectar vários sinais e sintomas, além de eliminar outras causas aparentes. A mucopolissacaridose III B é um desafio diagnóstico, particularmente nos estágios iniciais e na ausência de história familiar da doença.