ABSTRACT
There are few causes of treatable neurodevelopmental diseases described to date. Branched-chain ketoacid dehydrogenase kinase (BCKDK) deficiency causes branched-chain amino acid (BCAA) depletion and is linked to a neurodevelopmental disorder characterized by autism, intellectual disability and microcephaly. We report the largest cohort of patients studied, broadening the phenotypic and genotypic spectrum. Moreover, this is the first study to present newborn screening findings and mid-term clinical outcome. In this cross-sectional study, patients with a diagnosis of BCKDK deficiency were recruited via investigators' practices through a MetabERN initiative. Clinical, biochemical and genetic data were collected. Dried blood spot (DBS) newborn screening (NBS) amino acid profiles were retrieved from collaborating centres and compared to a healthy newborn reference population. Twenty-one patients with BCKDK mutations were included from 13 families. Patients were diagnosed between 8 months and 16 years (mean: 5.8 years, 43% female). At diagnosis, BCAA levels (leucine, valine and isoleucine) were below reference values in plasma and in CSF. All patients had global neurodevelopmental delay; 18/21 had gross motor function (GMF) impairment with GMF III or worse in 5/18, 16/16 intellectual disability, 17/17 language impairment, 12/17 autism spectrum disorder, 9/21 epilepsy, 12/15 clumsiness, 3/21 had sensorineural hearing loss and 4/20 feeding difficulties. No microcephaly was observed at birth, but 17/20 developed microcephaly during follow-up. Regression was reported in six patients. Movement disorder was observed in 3/21 patients: hyperkinetic movements (1), truncal ataxia (1) and dystonia (2). After treatment with a high-protein diet (≥ 2 g/kg/day) and BCAA supplementation (100-250 mg/kg/day), plasma BCAA increased significantly (P < 0.001), motor functions and head circumference stabilized/improved in 13/13 and in 11/15 patients, respectively. Among cases with follow-up data, none of the three patients starting treatment before 2 years of age developed autism at follow-up. The patient with the earliest age of treatment initiation (8 months) showed normal development at 3 years of age. NBS in DBS identified BCAA levels significantly lower than those of the normal population. This work highlights the potential benefits of dietetic treatment, in particular early introduction of BCAA. Therefore, it is of utmost importance to increase awareness about this treatable disease and consider it as a candidate for early detection by NBS programmes.
Subject(s)
Autism Spectrum Disorder , Intellectual Disability , Microcephaly , Infant, Newborn , Humans , Female , Infant , Male , Intellectual Disability/genetics , Autism Spectrum Disorder/diagnosis , Autism Spectrum Disorder/genetics , Neonatal Screening , Cross-Sectional Studies , Glia Maturation Factor , Amino Acids, Branched-Chain/metabolism , Microcephaly/geneticsABSTRACT
Background and objectives: Glycerol phenylbutyrate (GPB) has demonstrated safety and efficacy in patients with urea cycle disorders (UCDs) by means of its clinical trial program, but there are limited data in clinical practice. In order to analyze the efficacy and safety of GPB in clinical practice, here we present a national Spanish experience after direct switching from another nitrogen scavenger to GPB. Methods: This observational, retrospective, multicenter study was performed in 48 UCD patients (age 11.7 ± 8.2 years) switching to GPB in 13 centers from nine Spanish regions. Clinical, biochemical, and nutritional data were collected at three different times: prior to GPB introduction, at first follow-up assessment, and after one year of GPB treatment. Number of related adverse effects and hyperammonemic crisis 12 months before and after GPB introduction were recorded. Results: GPB was administered at a 247.8 ± 102.1 mg/kg/day dose, compared to 262.6 ± 126.1 mg/kg/day of previous scavenger (46/48 Na-phenylbutyrate). At first follow-up (79 ± 59 days), a statistically significant reduction in ammonia (from 40.2 ± 17.3 to 32.6 ± 13.9 µmol/L, p < 0.001) and glutamine levels (from 791.4 ± 289.8 to 648.6 ± 247.41 µmol/L, p < 0.001) was observed. After one year of GPB treatment (411 ± 92 days), we observed an improved metabolic control (maintenance of ammonia and glutamine reduction, with improved branched chain amino acids profile), and a reduction in hyperammonemic crisis rate (from 0.3 ± 0.7 to less than 0.1 ± 0.3 crisis/patients/year, p = 0.02) and related adverse effects (RAE, from 0.5 to less than 0.1 RAEs/patients/year p < 0.001). Conclusions: This study demonstrates the safety of direct switching from other nitrogen scavengers to GPB in clinical practice, which improves efficacy, metabolic control, and RAE compared to previous treatments.
ABSTRACT
BACKGROUND: Alteration of vitamin B12 metabolism can be genetic or acquired, and can result in anemia, failure to thrive, developmental regression and even irreversible neurologic damage. Therefore, early diagnosis and intervention is critical. Most of the neonatal cases with acquired vitamin B12 deficiency have been detected by clinical symptoms and only few of them trough NBS programs. We aim to assess the usefulness of the second-tier test: methylmalonic acid (MMA), methylcitric acid (MCA) and homocysteine (Hcys) in our newborn screening program and explore the implications on the detection of cobalamin (vitamin B12) related disorders, both genetic and acquired conditions. METHODS: A screening strategy using the usual primary markers followed by the analysis of MMA, MCA and Hcys as second tier-test in the first dried blood spot (DBS) was developed and evaluated. RESULTS: During the period 2015-2018 a total of 258,637 newborns were screened resulting in 130 newborns with acquired vitamin B12 deficiency (incidence 1:1989), 19 with genetic disorders (incidence 1:13,613) and 13 were false positive. No false negatives were notified. Concerning the second-tier test, the percentage of cases with MMA above the cut-off levels, both for genetic and acquired conditions was very similar (58% and 60%, respectively). Interestingly, the percentage of cases with increased levels of Hcys was higher in acquired conditions than in genetic disorders (87% and 47%, respectively). In contrast, MCA was high only in 5% of the acquired conditions versus in 53% of the genetic disorders, and it was always very high in all patients with propionic acidemia. CONCLUSIONS: When screening for methylmalonic acidemia and homocystinuria, differential diagnosis with acquired vitamin B12 deficiency should be done. The results of our strategy support the inclusion of this acquired condition in the NBS programs, as it is easily detectable and allows the adoption of corrective measures to avoid the consequences of its deficiency.
Subject(s)
Propionic Acidemia , Vitamin B 12 Deficiency , Homocysteine , Humans , Infant, Newborn , Methylmalonic Acid , Neonatal Screening , Vitamin B 12 , Vitamin B 12 Deficiency/diagnosis , Vitamin B 12 Deficiency/genetics , VitaminsABSTRACT
The Catalonian Newborn Screening Program (CNSP) began in 1969, in Barcelona. It was promoted by Dr. Juan Sabater Tobella and supported by Barcelona Provincial Council and Juan March Foundation. That is how the Institute of Clinical Biochemistry was born, whose aims were diagnosis, research and teaching, along with the spirit of contributing to the prevention of mental retardation. The CNSP began with the detection of phenylketonuria (PKU), and, in 1982, the Program was expanded with the inclusion of congenital hypothyroidism detection. Towards 1990, the Program covered almost 100% of all newborns (NB) in Catalonia. In 1999, the CNSP was expanded with the incorporation of cystic fibrosis. It took fourteen years, until 2013, to make the largest expansion so far, with the incorporation of 19 metabolic diseases to the screening panel. The detection of sickle cell disease began in 2015 and in 2017 the detection of severe combined immunodeficiency was included. Currently, the CNSP includes 24 diseases in its main panel. Since 1969, 2,787,807 NBs have been screened, of whom 1,724 have been diagnosed with any of these diseases, and 252 of other disorders by differential diagnosis with those included in the main panel. The global prevalence is 1: 1,617 NBs affected by any of the diseases included in the CNSP and 1: 1,140 NBs if incidental findings diagnosed through the CNSP are included.
El Programa de Cribado Neonatal de Cataluña (PCNC) se inició en el año 1969, en Barcelona, impulsado por el Dr. Juan Sabater Tobella y apoyado por la Diputación de Barcelona y la Fundación Juan March. Así nació el Instituto de Bioquímica Clínica para acometer funciones asistenciales, de investigación y docencia, con el espíritu de contribuir a la prevención del retraso mental. El PCNC se inició con la detección de la fenilcetonuria (PKU) y en el año 1982 se amplió con la detección del hipotiroidismo congénito. Hacia el año 1990 la cobertura territorial llegó casi al 100% de todos los recién nacidos en Cataluña. En 1999 se amplió el PCNC con la incorporación de la fibrosis quística y tras catorce años, en 2013, se realizó la ampliación más numerosa hasta ahora, con la incorporación de la detección de 19 enfermedades metabólicas hereditarias. En el año 2015 comenzó la detección de la enfermedad de células falciformes y en el 2017 la detección de la inmunodeficiencia combinada grave. Actualmente, el PCNC incluye la detección de 24 enfermedades. Desde su inicio en el año 1969, se han cribado 2.787.807 recién nacidos, de los cuales 1.724 han sido diagnosticados de alguna de las 24 enfermedades que componen nuestro panel principal y 252 por diagnóstico diferencial de las primeras. En total la prevalencia global es de 1:1.617 RN afectos de alguna de las enfermedades incluidas en el PCNC y de 1:1.140 RN si se incluyen los hallazgos incidentales encontrados.
Subject(s)
Neonatal Screening/history , History, 20th Century , History, 21st Century , Humans , Infant, Newborn , Neonatal Screening/methods , Neonatal Screening/organization & administration , SpainABSTRACT
El Programa de Cribado Neonatal de Cataluña (PCNC) se inició en el año 1969, en Barcelona, impulsado por el Dr. Juan Sabater Tobella y apoyado por la Diputación de Barcelona y la Fundación Juan March. Así nació el Instituto de Bioquímica Clínica para acometer funciones asistenciales, de investigación y docencia, con el espíritu de contribuir a la prevención del retraso mental. El PCNC se inició con la detección de la fenilcetonuria (PKU) y en el año 1982 se amplió con la detección del hipotiroidismo congénito. Hacia el año 1990 la cobertura territorial llegó casi al 100% de todos los recién nacidos en Cataluña. En 1999 se amplió el PCNC con la incorporación de la fibrosis quística y tras catorce años, en 2013, se realizó la ampliación más numerosa hasta ahora, con la incorporación de la detección de 19 enfermedades metabólicas hereditarias. En el año 2015 comenzó la detección de la enfermedad de células falciformes y en el 2017 la detección de la inmunodeficiencia combinada grave. Actualmente, el PCNC incluye la detección de 24 enfermedades. Desde su inicio en el año 1969, se han cribado 2.787.807 recién nacidos, de los cuales 1.724 han sido diagnosticados de alguna de las 24 enfermedades que componen nuestro panel principal y 252 por diagnóstico diferencial de las primeras. En total la prevalencia global es de 1:1.617 RN afectos de alguna de las enfermedades incluidas en el PCNC y de 1:1.140 RN si se incluyen los hallazgos incidentales encontrados
The Catalonian Newborn Screening Program (CNSP) began in 1969, in Barcelona. It was promoted by Dr. Juan Sabater Tobella and supported by Barcelona Provincial Council and Juan March Foundation. That is how the Institute of Clinical Biochemistry was born, whose aims were diagnosis, research and teaching, along with the spirit of contributing to the prevention of mental retardation. The CNSP began with the detection of phenylketonuria (PKU), and, in 1982, the Program was expanded with the inclusion of congenital hypothyroidism detection. Towards 1990, the Program covered almost 100% of all newborns (NB) in Catalonia. In 1999, the CNSP was expanded with the incorporation of cystic fibrosis. It took fourteen years, until 2013, to make the largest expansion so far, with the incorporation of 19 metabolic diseases to the screening panel. The detection of sickle cell disease began in 2015 and in 2017 the detection of severe combined immunodeficiency was included. Currently, the CNSP includes 24 diseases in its main panel. Since 1969, 2,787,807 NBs have been screened, of whom 1,724 have been diagnosed with any of these diseases, and 252 of other disorders by differential diagnosis with those included in the main panel. The global prevalence is 1: 1,617 NBs affected by any of the diseases included in the CNSP and 1: 1,140 NBs if incidental findings diagnosed through the CNSP are included
Subject(s)
Humans , Infant, Newborn , History, 15th Century , History, 16th Century , Neonatal Screening/history , Neonatal Screening/methods , Neonatal Screening/organization & administration , SpainABSTRACT
Patients with inborn errors of amino acid metabolism frequently show neuropsychiatric symptoms despite accurate metabolic control. This study aimed to gain insight into the underlying mechanisms of neural dysfunction. Here we analyzed the expression of brain-derived neurotrophic factor (BDNF) and 10 genes required for correct brain functioning in plasma and blood of patients with Urea Cycle Disorders (UCD), Maple Syrup Urine Disease (MSUD) and controls. Receiver-operating characteristic (ROC) analysis was used to evaluate sensitivity and specificity of potential biomarkers. CACNA2D2 (α2δ2 subunit of voltage-gated calcium channels) and MECP2 (methyl-CpG binding protein 2) mRNA and protein showed an excellent neural function biomarker signature (AUC ≥ 0,925) for recognition of MSUD. THBS3 (thrombospondin 3) mRNA and AABA gave a very good biomarker signature (AUC 0,911) for executive-attention deficits. THBS3, LIN28A mRNA, and alanine showed a perfect biomarker signature (AUC 1) for behavioral and mood disorders. Finally, a panel of BDNF protein and at least two large neural AAs showed a perfect biomarker signature (AUC 1) for recognition of psychomotor delay, pointing to excessive protein restriction as central causative of psychomotor delay. To conclude, our study has identified promising biomarker panels for neural function evaluation, providing a base for future studies with larger samples.
Subject(s)
Amino Acid Metabolism, Inborn Errors/physiopathology , Brain/physiopathology , Adolescent , Amino Acid Metabolism, Inborn Errors/genetics , Amino Acid Metabolism, Inborn Errors/metabolism , Biomarkers/metabolism , Brain/metabolism , Child , Child, Preschool , Female , Gene Expression Regulation , Humans , Infant , Infant, Newborn , Male , Synapses/metabolismABSTRACT
AIM: The aim of this study was to determine the relevance of HLA-DR7-DQ2 typing in a prospective cohort of paediatric coeliac disease patients from Southern Europe. METHODS: This cross-sectional study tested 249 paediatric patients with coeliac disease. HLA-DR3-DQ2 was typed in combination with HLA-DR7-DQ2 to screen for the HLA-DQ2 haplotype. The histological, analytical and clinical characteristics of the subjects were recorded. RESULTS: A total of 91 coeliac patients were diagnosed: 96.7% carried HLA-DQ2 and 4.4% carried HLA-DQ8. In percentage terms, 80.2% of patients carried HLA-DR3-DQ2 and 34.1% carried HLA-DR7-DQ2. We did not find significant differences between HLA-DR7-DQ2 and HLA-DR3-DQ2 paediatric patients with respect to histological damage and clinical characteristics, except for irritability and weight loss. These characteristics were more frequent in HLA-DQ2trans than in HLA-DQ2cis (22.2% vs. 0.0% [p = 0.035] and 55.6% vs. 21.4% [p = 0.017], respectively). Coeliac-specific autoantibody levels were higher in HLA-DQ2cis than one half of HLA-DQ2trans patients (105.5 vs. 19.2 U/mL, p = 0.014). CONCLUSION: Small clinical differences were found between paediatric coeliac patients carrying HLA-DR7-DQ2 and HLA-DR3-DQ2. For a correct screening of HLA-DQ2, at least in our geographical population, the HLA-DR7-DQ2 haplotype should be typed due to its frequency and clinical presentation.
