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Phenylketonuria, the most common inherited metabolic disease, results from a deficiency of phenylalanine hydroxylase enzyme activity that causes high blood phenylalanine levels. Most adults do not adhere to the gold standard therapy: lifelong treatment with a low-phenylalanine diet. Elevated and fluctuating phenylalanine levels in untreated adults can cause white matter abnormalities, neurological symptoms, and cognitive dysfunction (executive function). Pegvaliase, a derivative of the phenylalanine ammonia-lyase enzyme, metabolizes phenylalanine to trans-cinnamic acid and ammonia, and is approved by the US Food and Drug Administration and European Medicines Agency for subcutaneous administration in adults with phenylketonuria and blood phenylalanine concentrations > 600 μmol/L. In clinical trials, it reduced blood phenylalanine, even in patients consuming an unrestricted diet. We report longitudinal results on the first three such adults, in whom phenylalanine levels were quantified monthly, starting 1 year before pegvaliase administration and continuing through achievement of a pegvaliase response (defined as six consecutive monthly blood phenylalanine concentrations < 360 μmol/L while consuming an unrestricted diet). Brain magnetic resonance imaging (MRI) and neuropsychological assessments were performed before starting therapy and after response was achieved. Our results show that all three patients had significantly reduced white matter hyperintensities on brain MRI and improved executive function on neuropsychological assessment, especially on the Paced Auditory Serial Addition Test, which is known to be very sensitive to white matter functioning. To the best of our knowledge, this is the first report of concomitant improvements in cognitive performance and white matter damage after a pharmacological intervention to normalize phenylalanine levels in adults with phenylketonuria consuming an unrestricted diet., (© 2024 The Author(s). European Journal of Neurology published by John Wiley & Sons Ltd on behalf of European Academy of Neurology.)

Objective: Patients with phenylketonuria (PKU) require a strict diet to maintain phenylalanine (Phe) levels within the desired range. However, the diet can be onerous, resulting in poor adherence. We carried out the first online national survey in Italy to better understand the perceptions, knowledge, and experiences of both patients with PKU and caregivers with the goal of improving patient outcomes., Methods: An online survey of 35 questions to patients and 36 questions to caregivers was distributed in September 2022 through physicians and relevant Italian associations. The information collected included knowledge and impact of PKU, unmet needs, knowledge of available drugs, and satisfaction with therapy., Results: Overall, 241 questionnaires were completed by 85 patients and 156 caregivers (96.0% were parents). Knowledge of the pathogenic basis of PKU was generally high. The most common patient-reported symptoms were agitation/anxiety (48.8%), fatigue (41.1%), mood disorders (39.8%), and difficulty concentrating (33.4%). Different perspectives on adherence to a low-Phe diet were observed (22.9% of patients reported strict adherence vs. 47.0% of caregivers). Drugs that allow more freedom were needed by 49.4% of patients and 61.7% of caregivers, along with a wider range of choices of non-dietary treatments (48.2% and 60.0%, respectively). Unmet informational needs of patients included PKU and pregnancy, complications, travel, sports, and transition into adult care., Conclusions: Our data showed that patients with PKU and their caregivers reported difficulties in adherence to diet therapy and indicated interest in new therapeutic approaches. Apparent differences between patient and caregiver perspectives were identified. More informational resources on PKU are needed.

Objective: The aim of this study is to present a series of case studies on the real-life use of pegvaliase in Italy in managing patients affected by phenylketonuria (PKU) and provide practical insight and support to healthcare professionals currently approaching and facing this novel enzyme substitution therapy., Methods: A panel of 11 PKU experts from seven leading Italian treatment centers attended online virtual meetings with the aim of reviewing their clinical and practical experiences with pegvaliase based on occurred cases. In selecting the cases, specific consideration was given to the nationwide representation of the centers involved and to the number of patients with PKU managed. Cases were thoroughly reviewed, with comprehensive discussions enabling the identification of key take-home messages regarding pegvaliase therapy., Results: The panel discussed 18 cases, 11 males and 7 females (age range 17-43 years). At the last follow-up (up to 111 weeks after pegvaliase initiation), 11 out of 18 patients (61%) reached Phe levels below 600 μmol/l. Outcomes varied significantly across cases. All cases underscore the potential of pegvaliase in reducing Phe levels, enhancing the quality of life, and promoting social skills and independence. Additionally, the cases highlight the challenges associated with pegvaliase therapy, including managing adverse events and ensuring patient motivation and adherence., Conclusion: This is the first report about the Italian experience of managing patients affected by PKU with pegvaliase. Given the limited real-world data on the use of pegvaliase in PKU management, this case series offers valuable insights into the practical implementation and management of pegvaliase therapy in this Country. Continued research and data collection will be crucial to confirm and progress with this treatment. Despite potential challenges, pegvaliase therapy represents a substantial promise in managing PKU in Italy. Patient education, personalized treatment approaches, and careful monitoring are important to ensure optimal patient outcomes., Competing Interests: Declaration of competing interest None, (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Receiving information in the case of a positive or false-positive expanded newborn screening (ENBS) result for metabolic diseases is a stressful event. The availability of psychological support to families is crucial across the different communication steps and is recommended by different guidelines and position papers. However, more information is needed about the availability of psychological resources in the ENBS process. This national survey aimed to provide an overview of the availability of psychological resources for parents who received communication of positivity at the ENBS in the 23 Italian centers and how the support is provided to parents. An online survey was sent to the Heads of the ENBS centers asking about the availability of a clinical psychologist, their involvement in the ENBS process, and an estimation of parents receiving psychological support. More than 60% of the centers report having a clinical psychologist in the ENBS team; however, in more than 50% of cases, the psychologist does not participate in the consultation with parents (nor for the first consultation post-positivity or at confirmation of diagnosis). Furthermore, nearly 60% of the centers reported the experience of parental rejection of psychological sessions.  Conclusion: There is a need for harmonization among the Italian ENBS centers concerning the availability of psychological resources and how these resources are provided to families. Parents' needs remained only partially fulfilled. What is Known: • Receiving communication of positivity at the ENBS can be highly stressful for parents and requires adequate psychological support. • The guidelines recommend psychological support for parents during the ENBS process. What is New: • Only 14/23 (60.9%) of Italian ENBS centers have a clinical psychologist within the team. • In half of the consultations with parents receiving communication of positivity, the clinical psychologist is never involved., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

In the last two decades, the development of high-throughput diagnostic methods and the availability of effective treatments have increased the interest in newborn screening for lysosomal storage disorders. However, long-term follow-up experience is needed to clearly identify risks, benefits and challenges. We report our 8-year experience of screening and follow-up on about 250,000 neonates screened for four lysosomal storage diseases (Pompe disease, mucopolysaccharidosis type I, Fabry disease, Gaucher disease), using the enzyme activity assay by tandem mass spectrometry, and biomarker quantification as a second-tier test. Among the 126 positive newborns (0.051%), 51 infants were confirmed as affected (positive predictive value 40%), with an overall incidence of 1:4874. Of these, three patients with infantile-onset Pompe disease, two with neonatal-onset Gaucher disease and four with mucopolysaccharidosis type I were immediately treated. Furthermore, another four Gaucher disease patients needed treatment in the first years of life. Our study demonstrates the feasibility and effectiveness of newborn screening for lysosomal storage diseases. Early diagnosis and treatment allow the achievement of better patient outcomes. Challenges such as false-positive rates, the diagnosis of variants of uncertain significance or late-onset forms and the lack of treatment for neuronopathic forms, should be addressed.

Background: Zellweger spectrum disorders (ZSD) and X-linked adrenoleukodystrophy (X-ALD) are inherited metabolic diseases characterized by dysfunction of peroxisomes, that are essential for lipid metabolism and redox balance. Oxidative stress has been reported to have a significant role in the pathogenesis of neurodegenerative diseases such as peroxisomal disorders, but little is known on the intracellular activation of Mitogen-activated protein kinases (MAPKs). Strictly related to oxidative stress, a correct autophagic machinery is essential to eliminated oxidized proteins and damaged organelles. The aims of the current study are to investigate a possible implication of MAPK pathways and autophagy impairment as markers and putative therapeutic targets in X-ALD and ZSDs., Methods: Three patients with ZSD (2 M, 1 F; age range 8-17 years) and five patients with X-ALD (5 M; age range 5- 22 years) were enrolled. A control group included 6 healthy volunteers. To evaluate MAPKs pathway, p-p38 and p-JNK were assessed by western blot analysis on peripheral blood mononuclear cells. LC3II/LC3I ratio was evaluated ad marker of autophagy., Results: X-ALD and ZSD patients showed elevated p-p38 values on average 2- fold (range 1.21- 2.84) and 3.30-fold (range 1.56- 4.26) higher when compared with controls, respectively. p-JNK expression was on average 12-fold (range 2.20-19.92) and 2.90-fold (range 1.43-4.24) higher in ZSD and X-ALD patients than in controls. All patients had altered autophagic flux as concluded from the reduced LC3II/I ratio., Conclusions: In our study X-ALD and ZSD patients present an overactivation of MAPK pathways and an inhibition of autophagy. Considering the absence of successful therapies and the growing interest towards new therapies with antioxidants and autophagy inducers, the identification and validation of biomarkers to monitor optimal dosing and biological efficacy of the treatments is of prime interest., (© 2023. The Author(s).)

Cognitive and psychiatric disorders are well documented across the lifetime of patients with inborn errors of metabolism (IEMs). Gut microbiota impacts behavior and cognitive functions through the gut-brain axis (GBA). According to recent research, a broad spectrum of GBA disorders may be influenced by a perturbed Tryptophan (Trp) metabolism and are associated with alterations in composition or function of the gut microbiota. Furthermore, early-life diets may influence children's neurodevelopment and cognitive deficits in adulthood. In Phenylketonuria (PKU), since the main therapeutic intervention is based on a life-long restrictive diet, important alterations of gut microbiota have been observed. Studies on PKU highlight the impact of alterations of gut microbiota on the central nervous system (CNS), also investigating the involvement of metabolic pathways, such as Trp and kynurenine (KYN) metabolisms, involved in numerous neurodegenerative disorders. An alteration of Trp metabolism with an imbalance of the KYN pathway towards the production of neurotoxic metabolites implicated in numerous neurodegenerative and inflammatory diseases has been observed in PKU patients supplemented with Phe-free amino acid medical foods (AA-MF). The present review investigates the possible link between gut microbiota and the brain in IEMs, focusing on Trp metabolism in PKU. Considering the evidence collected, cognitive and behavioral well-being should always be monitored in routine IEMs clinical management. Further studies are required to evaluate the possible impact of Trp metabolism, through gut microbiota, on cognitive and behavioral functions in IEMs, to identify innovative dietetic strategies and improve quality of life and mental health of these patients., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Background: Phenylketonuria (PKU) is a rare inborn error of metabolism affecting the catabolism of phenylalanine (Phe). To date, findings regarding health-related quality of life (HRQoL) in adults with early-treated classical PKU are discrepant. Moreover, little is known about metabolic, demographic, and cognitive factors associated with HRQoL. Hence, we aimed to investigate HRQoL and its association with demographic, metabolic, and cognitive characteristics in a large European sample of adults with early-treated classical PKU., Results: This cross-sectional study included 124 adults with early-treated classical PKU from Hungary, Italy, Spain, Switzerland, and Turkey. All participants prospectively completed the PKU quality of life questionnaire (PKU-QoL), a questionnaire specifically designed to evaluate the impact of PKU and its treatment on HRQoL in individuals with PKU. In addition, information about Phe levels (concurrent and past year), demographic (age and sex), and cognitive variables (intelligence quotient, IQ) were collected. Most domains revealed little or no impact of PKU on HRQoL and more than three-quarters of the patients rated their health status as good, very good, or excellent. Nevertheless, some areas of concern for patients were identified. Patients were worried about the guilt that they experience if they do not adhere to the dietary protein restriction and they were most concerned about high Phe levels during pregnancy. Further, tiredness was the most affected symptom, and the supplements' taste was considered a main issue for individuals with PKU. The overall impact of PKU on HRQoL was higher in women (U = 1315.5, p = .012) and in adults with a lower IQ (r s  = - 0.448, p = .005). The overall impact of dietary protein restriction was higher in adults with higher concurrent Phe levels (r s = 0.272, p = .007) and higher Phe levels during the past year (r s = 0.280, p = .009)., Conclusion: The impact of PKU on most domains assessed in the PKU-QoL was considered to be low. These results likely reflect the successful implementation of the newborn screening resulting in the prevention of severe adverse long-term outcomes. However, a particular clinical focus should be given to patients with lower IQ, higher Phe levels, and women, as these variables were associated with a lower HRQoL., (© 2023. Institut National de la Santé et de la Recherche Médicale (INSERM).)

Fabry disease is an X-linked progressive lysosomal disorder, due to α-galactosidase A deficiency. Patients with a classic phenotype usually present in childhood as a multisystemic disease. Patients presenting with the later onset subtypes have cardiac, renal and neurological involvements in adulthood. Unfortunately, the diagnosis is often delayed until the organ damage is already irreversibly severe, making specific treatments less efficacious. For this reason, in the last two decades, newborn screening has been implemented to allow early diagnosis and treatment. This became possible with the application of the standard enzymology fluorometric method to dried blood spots. Then, high-throughput multiplexable assays, such as digital microfluidics and tandem mass spectrometry, were developed. Recently DNA-based methods have been applied to newborn screening in some countries. Using these methods, several newborn screening pilot studies and programs have been implemented worldwide. However, several concerns persist, and newborn screening for Fabry disease is still not universally accepted. In particular, enzyme-based methods miss a relevant number of affected females. Moreover, ethical issues are due to the large number of infants with later onset forms or variants of uncertain significance. Long term follow-up of individuals detected by newborn screening will improve our knowledge about the natural history of the disease, the phenotype prediction and the patients' management, allowing a better evaluation of risks and benefits of the newborn screening for Fabry disease.

Phenylketonuria (PKU) is an inherited metabolic disease characterized by a defective conversion of phenylalanine (Phe) to tyrosine, potentially leading to Phe accumulation in the brain. Dietary restriction since birth has led to normal cognitive development. However, PKU patients can still develop cognitive or behavioral abnormalities and subtle neurological deficits. Despite the increasing evidence in the field, the assessment of neurocognitive, psychopathological, and neurological follow-up of PKU patients at different ages is still debated. The high interindividual variability in the cognitive outcome of PKU patients makes the specificity of the neurocognitive and behavioral assessment extremely challenging. In the present paper, a multidisciplinary panel of Italian PKU experts discussed different tools available for cognitive, psychopathological, and neurological assessment at different ages based on the existing literature and daily clinical practice. This study aims to provide evidence and a real-life-based framework for a specific clinical assessment of pediatric, adolescent, and adult patients affected by PKU., (© 2022. The Author(s).)

Pompe disease (PD) is a progressive neuromuscular disorder caused by a lysosomal acid α-glucosidase (GAA) deficiency. Enzymatic replacement therapy is available, but early diagnosis by newborn screening (NBS) is essential for early treatment and better outcomes, especially with more severe forms. We present results from 7 years of NBS for PD and the management of infantile-onset (IOPD) and late-onset (LOPD) patients, during which we sought candidate predictive parameters of phenotype severity at baseline and during follow-up. We used a tandem mass spectrometry assay for α-glucosidase activity to screen 206,741 newborns and identified 39 positive neonates (0.019%). Eleven had two pathogenic variants of the GAA gene (3 IOPD, 8 LOPD); six carried variants of uncertain significance (VUS). IOPD patients were treated promptly and had good outcomes. LOPD and infants with VUS were followed; all were asymptomatic at the last visit (mean age 3.4 years, range 0.5-5.5). Urinary glucose tetrasaccharide was a useful and biomarker for rapidly differentiating IOPD from LOPD and monitoring response to therapy during follow-up. Our study, the largest reported to date in Europe, presents data from longstanding NBS for PD, revealing an incidence in North East Italy of 1/18,795 (IOPD 1/68,914; LOPD 1/25,843), and the absence of mortality in IOPD treated from birth. In LOPD, rigorous long-term follow-up is needed to evaluate the best time to start therapy. The high pseudodeficiency frequency, ethical issues with early LOPD diagnosis, and difficulty predicting phenotypes based on biochemical parameters and genotypes, especially in LOPD, need further study., Competing Interests: The authors declare no conflict of interest., (© 2022 Published by Elsevier Inc.)

Newborn screening (NBS) for inborn errors of metabolism is one of the most advanced tools for secondary prevention in medicine, as it allows early diagnosis and prompt treatment initiation. The expanded newborn screening was introduced in Italy between 2016 and 2017 (Law 167/2016; DM 13 October 2016; DPCM 12-1-2017). A total of 1,586,578 infants born in Italy were screened between January 2017 and December 2020. For this survey, we collected data from 15 Italian screening laboratories, focusing on the metabolic disorders identified by tandem mass spectrometry (MS/MS) based analysis between January 2019 and December 2020. Aminoacidemias were the most common inborn errors in Italy, and an equal percentage was observed in detecting organic acidemias and mitochondrial fatty acids beta-oxidation defects. Second-tier tests are widely used in most laboratories to reduce false positives. For example, second-tier tests for methylmalonic acid and homocysteine considerably improved the screening of CblC without increasing unnecessary recalls. Finally, the newborn screening allowed us to identify conditions that are mainly secondary to a maternal deficiency. We describe the goals reached since the introduction of the screening in Italy by exchanging knowledge and experiences among the laboratories.

Mucopolysaccharidosis type II (MPS II) is a multisystemic lysosomal storage disorder caused by deficiency of the iduronate 2-sulfatase enzyme. Currently, enzyme replacement therapy (ERT) with recombinant idursulfase is the main treatment available to decrease morbidity and improve quality of life. However, infusion-associated reactions (IARs) are reported and may limit access to treatment. When premedication or infusion rate reductions are ineffective for preventing IARs, desensitization can be applied. To date, only two MPS II patients are reported to have undergone desensitization. We report a pediatric patient with recurrent IARs during infusion successfully managed with gradual desensitization. Our protocol started at 50% of the standard dosage infused at concentrations from 0.0006 to 0.06 mg/ml on weeks 1 and 2, followed by 75% of the standard dosage infused at concentrations from 0.0009 to 0.09 mg/ml on weeks 3 and 4, and full standard dosage thereafter, infused at progressively increasing concentrations until the standard infusion conditions were reached at 3 months. Our experience can be used in the management of MPS II patients presenting IARs to idursulfase infusion, even when general preventive measures are already administered., Competing Interests: The authors declare no conflict of interest., (© 2022 The Authors.)

Background: Phenylketonuria (PKU) is a rare inherited metabolic disorder caused by defects in the phenylalanine-hydroxylase gene (PAH), the enzyme catalyzing the conversion of phenylalanine to tyrosine. PAH impairment causes phenylalanine accumulation in the blood and brain, with a broad spectrum of pathophysiological and neurological consequences for patients. Prevalence of disease varies, with peaks in some regions and countries, including Italy. A recent expert survey described the real-life of clinical practice for PKU in Italy, revealing inhomogeneities in disease management, particularly concerning approach to pharmacotherapy with sapropterin hydrochloride, analogous of the natural PAH co-factor, allowing disease control in a subset of patients. Therefore, the purpose of this paper is to continue the work initiated with the expert survey paper, to provide national guidances aiming to harmonize and optimize patient care at a national level., Participants: The Consensus Group, convened by 10 Steering Committee members, consisted of a multidisciplinary crowd of 46 experts in the management of PKU in Italy., Consensus Process: The Steering Committee met in a series of virtual meeting in order to discuss on clinical focuses to be developed and analyzed in guidance statements, on the basis of expert practice based evidence, large systematic literature review previously performed in the expert survey paper, and evidence based consensus published. Statements were re-discussed and refined during consensus conferences in the widest audience of experts, and finally submitted to the whole consensus group for a modified-Delphi voting., Results: Seventy three statements, divided in two main clinical areas, PKU management and Pharmacotherapy, achieved large consensus in a multidisciplinary group of expert in different aspects of disease. Importantly, these statements involve guidances for the use of sapropterin dihydrochloride, still not sufficiently implemented in Italy, and a set of good practice to approach the use of novel enzyme replacement treatment pegvaliase., Conclusions: This evidence-based consensus provides a minimum set of guidances for disease management to be implemented in all PKU centers. Moreover, these guidances represent the first statement for sapropterin dihydrochloride use, implementation and standardization in Italy, and a guide for approaching pegvaliase treatment at a national level on a consistent basis., (© 2021. The Author(s).)

Fabry disease (FD) is a progressive multisystemic lysosomal storage disease. Early diagnosis by newborn screening (NBS) may allow for timely treatment, thus preventing future irreversible organ damage. We present the results of 5.5 years of NBS for FD by α-galactosidase A activity and globotriaosylsphingosine (lyso-Gb 3 ) assays in dried blood spot through a multiplexed MS/MS assay. Furthermore, we report our experience with long-term follow-up of positive subjects. We screened more than 170,000 newborns and 22 males were confirmed to have a GLA gene variant, with an incidence of 1:7879 newborns. All patients were diagnosed with a variant previously associated with the later-onset phenotype of FD or carried an unclassified variant (four patients) or the likely benign p.Ala143Thr variant. All were asymptomatic at the last visit. Although lyso-Gb 3 is not considered a reliable second tier test for newborn screening, it can simplify the screening algorithm when its levels are elevated at birth. After birth, plasma lyso-Gb 3 is a useful marker for non-invasive monitoring of all positive patients. Our study is the largest reported to date in Europe, and presents data from long-term NBS for FD that reveals the current incidence of FD in northeastern Italy. Our follow-up data describe the early disease course and the trend of plasma lyso-Gb 3 during early childhood.

Objective: Aromatic L-amino acid decarboxylase (AADC) deficiency is a rare inherited autosomal recessive disorder of biogenic amine metabolism. Diagnosis requires analysis of neurotransmitter metabolites in cerebrospinal fluid, AADC enzyme activity analysis, or molecular analysis of the DDC gene. 3-O-methyldopa (3-OMD) is a key screening biomarker for AADC deficiency., Methods: We describe a rapid method for 3-OMD determination in dried blood spots (DBS) using flow-injection analysis tandem mass spectrometry with NeoBase™ 2 reagents and 13 C 6 -tyrosine as an internal standard, which are routinely used in high-throughput newborn screening. We assessed variability using quality control samples over a range of 3-OMD concentrations., Results: Within-day and between-day precision determined with quality control samples demonstrated coefficients of variation <15%. 3-OMD concentrations in 1000 healthy newborns revealed a mean of 1.33 μmol/L (SD ± 0.56, range 0.61-3.05 μmol/L), 100 non-AADC control subjects (age 7 days - 1 year) showed a mean of 1.19 μmol/L (SD ± 0.35-2.00 μmol/L), and 81 patients receiving oral L-Dopa had a mean 3-OMD concentration of 14.90 μmol/L (SD ± 14.18, range 0.4-80.3 μmol/L). A patient with confirmed AADC was retrospectively analyzed and correctly identified (3-OMD 10.51 μmol/L). In April 2020, we started a pilot project for identifying AADC deficiency in DBSs routinely submitted to the expanded newborn screening program. 3-OMD concentrations were measured in 21,867 samples; no patients with AADC deficiency were identified. One newborn had a high 3-OMD concentration due to maternal L-Dopa treatment., Discussion: We demonstrated a rapid new method to identify AADC deficiency using reagents and equipment already widely used in newborn screening programs. Although our study is limited, introduction of our method in expanded neonatal screening is feasible and could facilitate deployment of screening, allowing for early diagnosis that is important for effective treatment., (Copyright © 2021. Published by Elsevier Inc.)

Acute intoxication-type inborn errors of metabolism (IT-IEM) such as urea cycle disorders and non-acute IT-IEM such as phenylketonuria have a major impact on paediatric patients' life. Patients have to adhere to a strict diet but may face neurocognitive impairment and - in acute diseases - metabolic decompensations nevertheless. Research on the subjective burden of IT-IEM remains sparse. Studies with appropriate sample sizes are needed to make valid statements about health-related quality of life (HrQoL) in children and adolescents with IT-IEM. Six international metabolic centres contributed self-reports and proxy reports of HrQoL (assessed with the Paediatric Quality of Life Inventory) to the final data set (n = 251 patients; age range 2.3-18.8 years). To compare HrQoL of the patient sample with norm data and between acute and non-acute IT-IEM, t tests were conducted. To examine the influence of child age, sex, diagnosis and current dietary treatment on HrQoL, multiple linear regression analyses were conducted. Self-reports and proxy reporst showed significantly lower HrQoL total scores for children with IT-IEM compared to healthy children. Current dietary treatment significantly predicted lower proxy reported total HrQoL. Children with non-acute IT-IEM reported significantly lower psychosocial health and emotional functioning than children with acute IT-IEM. The patient sample showed significantly impaired HrQoL and a diet regimen remains a risk factor for lower HrQoL. Differences in HrQoL between acute and non-acute IT-IEM subgroups indicate that factors beyond symptom severity determine the perception of disease burden. Identifying these factors is of crucial importance to develop and implement appropriate interventions for those in need., (© 2020 SSIEM.)

Objectives Mucopolysaccharidosis type I (MPS I) was added to our expanded screening panel in 2015. Since then, 127,869 newborns were screened by measuring α-L-iduronidase (IDUA) enzyme activity with liquid chromatography tandem mass spectrometry (LC-MS/MS). High false positives due to frequent pseudodeficiency alleles prompted us to develop a second-tier test to quantify glycosaminoglycan (GAG) levels in dried blood spot (DBS). Methods Heparan-sulfate (HS) and dermatan-sulfate (DS) were measured with LC-MS/MS after methanolysis. DBSs were incubated with methanolic-HCl 3 N at 65 °C for 45 min. Chromatographic separation used an amide column with a gradient of acetonitrile and water with 10 mM ammonium acetate in a 9-min run. The method was validated for specificity, linearity, lower limit of quantification (LOQ), accuracy and precision. Results Intra- and inter-day coefficients of variation were <15% for both metabolites. Reference values in 40 healthy newborns were: HS mean 1.0 mg/L, 0-3.2; DS mean 1.5 mg/L, 0.5-2.7). The two confirmed newborn MPS I patients had elevated HS (4.9-10.4 mg/L, n.v. <3.2) and DS (7.4-8.8 mg/L, n.v. <2.7). Since its introduction in February 2019, the second-tier test reduced the recall rate from 0.046% to 0.006%. Among 127,869 specimens screened, the incidence was 1:63,935 live births. Both patients started enzyme replacement therapy (ERT) within 15 days of birth and one of them received allogenic hematopoietic stem cell transplantation (HSCT) at ht age of 6 months. Conclusions GAGs in DBS increased the specificity of newborn screening for MPS I by reducing false-positives due to heterozygosity or pseudodeficiency. Early diagnosis and therapeutical approach has improved the outcome of our patients with MPS I.

Mucopolysaccharidosis type I (MPS I) is a progressive lysosomal storage disease, with neurological and visceral involvement, in which early diagnosis through newborn screening (NBS) and early treatment can improve outcomes. We present our first 5 years of experience with laboratory and clinical management of NBS for MPS I. Since 2015, we have screened 160,011 newborns by measuring α-L-iduronidase (IDUA) activity and, since 2019, glycosaminoglycans (GAGs) in dried blood spot (DBS) as a second-tier test. Positive screening patients were referred to our clinic for confirmatory clinical and molecular testing. We found two patients affected by MPS I (incidence of 1:80,005). Before the introduction of second-tier testing, we found a high rate of false-positives due to pseudodeficiency. With GAG analysis in DBS as a second-tier test, no false-positive newborns were referred to our clinic. The confirmed patients were early treated with enzyme replacement therapy and bone-marrow transplantation. For both, the clinical outcome of the disease is in the normal range. Our experience confirms that NBS for MPS I is feasible and effective, along with the need to include GAG assay as a second-tier test. Follow-up of the two positive cases identified confirms the importance of early diagnosis through NBS and early treatment to improve the outcome of these patients.

The gold standard treatment for phenylketonuria (PKU) is a lifelong low-phenylalanine (Phe) diet supplemented with Phe-free protein substitutes. Adherence to therapy becomes difficult after childhood. Supplementing with large neutral amino acids (LNAAs) has been proposed as an alternative medication to Phe-free protein substitutes (i.e., amino acid mixtures). The aim of this study was to evaluate adherence to therapy and quality of life (QoL) in a cohort of sub-optimally controlled adult PKU patients treated with a new LNAA formulation. Twelve patients were enrolled in a 12-month-trial of slow-release LNAAs (1g/kg/day) plus a Phe-restricted diet. Medication adherence was measured with the Morisky Green Levine Medication Adherence Scale; the QoL was measured using the phenylketonuria-quality of life (PKU-QoL) questionnaire. Phe, tyrosine (Tyr) levels, and Phe/Tyr ratios were measured fortnightly. Before treatment, 3/12 patients self-reported a 'medium' adherence to medication and 9/12 reported a low adherence; 60% of patients reported a full adherence over the past four weeks. After 12 months of LNAA treatment, all patients self-reported a high adherence to medication, with 96% reporting a full adherence. Phe levels remained unchanged, while Tyr levels increased in most patients. The Phy/Tyr ratio decreased. All patients had a significant improvement in the QoL. LNAAs may give patients a further opportunity to improve medication adherence and, consequently, their QoL.

The standard treatment for phenylketonuria (PKU) is a lifelong low-phenylalanine (Phe) diet, supplemented with Phe-free protein substitutes; however, adult patients often show poor adherence to therapy. Alternative treatment options include the use of large neutral amino acids (LNAA). The aim of this study was to determine the Phe, tyrosine (Tyr), and Phe/Tyr ratio in a cohort of sub-optimally controlled adult patients with classical PKU treated with a new LNAA formulation. Twelve patients received a Phe-restricted diet plus a slow-release LNAA product taken three times per day, at a dose of 1 g/kg body weight (mean 0.8 ± 0.24 g/kg/day), over a 12-month period. The product is in a microgranulated formulation, which incorporates all amino acids and uses sodium alginate as a hydrophilic carrier to prolong its release. This LNAA formulation provides up to 80% of the total protein requirement, with the rest of the protein supplied by natural food. Patients had fortnightly measurements of Phe and Tyr levels over a 12-month period after the introduction of LNAA. All patients completed the 12-month treatment period. Overall, adherence to the new LNAA tablets was very good compared with a previous amino acid mixture, for which taste was a major complaint by patients. Phe levels remained unchanged ( p = 0.0522), and Tyr levels increased ( p = 0.0195). Consequently, the Phe/Tyr ratio decreased significantly ( p < 0.05) in the majority of patients treated. In conclusion, LNAA treatment increases Tyr levels in sub-optimally controlled adult PKU patients, while offering the potential to improve their adherence to treatment., Competing Interests: Alberto Burlina has received advisory board honoraria, speaker fees, and travel support from Biomarin, Nutricia, APR, PIAM Farmaceutici, Sanofi Genzyme, Takeda Shire, and Orphan Recordati. Alessandro P. Burlina has received advisory board honoraria, speaker fees, and travel support from Amicus Therapeutics, Biomarin, Freeline Therapeutics, Nutricia, PIAM Farmaceutici, and Sanofi Genzyme. The other authors declare no conflicts of interest.

The increasing availability of treatments and the importance of early intervention have stimulated interest in newborn screening for lysosomal storage diseases. Since 2015, 112,446 newborns in North Eastern Italy have been screened for four lysosomal disorders-mucopolysaccharidosis type I and Pompe, Fabry and Gaucher diseases-using a multiplexed tandem mass spectrometry (MS/MS) assay system. We recalled 138 neonates (0.12%) for collection of a second dried blood spot. Low activity was confirmed in 62 (0.06%), who underwent confirmatory testing. Twenty-five neonates (0.02%) were true positive: eight with Pompe disease; seven with Gaucher disease; eight with Fabry disease; and two with Mucopolysaccharidosis type I. The combined incidence of the four disorders was 1 in 4497 births. Except for Pompe disease, a second-tier test was implemented. We conclude that newborn screening for multiple lysosomal storage diseases combined with a second-tier test can largely eliminate false-positives and achieve rapid diagnosis., Competing Interests: Conflicts of InterestA.B.B. has received speaker honoraria and travel support from Sanofi Genzyme, Biomarin and Takeda-Shire. He is a member of the European Advisory Board of Nutricia Danone and Biomarin. A.P.B. has received speaker honoraria and travel support from Sanofi Genzyme and Amicus Therapeutics. He is a member of the European Advisory Board of the Fabry Registry, which is sponsored by Sanofi Genzyme. G.P. has received speaker honoraria and travel support from PerkinElmer, Biomarin, Sanofi Genzyme and Takeda-Shire. L.S., C.C., L.R., D.G., and G.D., declare that they have no conflict of interest., (© 2019 by the authors.)

Newborn screening for phenylketonuria (PKU) and early introduction of dietary therapy has been remarkably successful in preventing the severe neurological features of PKU, including mental retardation and epilepsy. However, concerns remain that long-term outcome is still suboptimal, particularly in adult patients who are no longer on strict phenylalanine-restricted diets. With our systematic literature review we aimed to describe the neurological phenotype of adults with early-treated phenylketonuria (ETPKU). The literature search covered the period from 1 January 1990 up to 16 April 2018, using the NLM MEDLINE controlled vocabulary. Of the 643 records initially identified, 83 were included in the analysis. The most commonly reported neurological signs were tremor and hyperreflexia. The overall quality of life (QoL) of ETPKU adults was good or comparable to control populations, and there was no evidence for a significant incidence of psychiatric disease or social difficulties. Neuroimaging revealed that brain abnormalities are present in ETPKU adults, but their clinical significance remains unclear. Generally, intelligence quotient (IQ) appears normal but specific deficits in neuropsychological and social functioning were reported in early-treated adults compared with healthy individuals. However, accurately defining the prevalence of these deficits is complicated by the lack of standardized neuropsychological tests. Future research should employ standardized neurological, neuropsychological, and neuroimaging protocols, and consider other techniques such as advanced imaging analyses and the recently validated PKU-specific QoL questionnaire, to precisely define the nature of the impairments within the adult ETPKU population and how these relate to metabolic control throughout life., (© 2019 The Authors. Journal of Inherited Metabolic Disease published by John Wiley & Sons Ltd on behalf of SSIEM.)

Dietary treatment is the cornerstone of therapy for phenylketonuria (PKU), but adherence to low- phenylalanine diet progressively decreases after adolescence. We designed a survey to characterize the dietary habits of Italian adult PKU patients and to identify psychological factors influencing disease perception and adherence to diet. Participants to the survey ( n  = 111; response rate 94%) were asked to complete a structured questionnaire. Patients appeared to have an altered perception and awareness of the disease. About 40% of them did not consider PKU a disease and, despite declaring regular monitoring of phenylalanine levels (85%), nearly half of them reported a high plasma value over the last 6 months (>600 μmol/L, 48%) or were unable to specify it (31%). Adherence to PKU diet was unsatisfactory, with increased consumption of natural protein sources and reduced daily use of amino-acid supplements (<4-5 times/day in 82% patients). In addition to the intrinsic characteristics of AA formula (palatability, ease of use), the most important factor influencing their consumption was the increased social pressure associated with their use (55%). Plasma phenylalanine periodical measurements (61%) and examinations at metabolic centers (49%) were considered relevant for compliance to diet. In Italian adult PKU patients dietary management was found to be inadequate, likely due to inappropriate perception and knowledge of the disease, and lack of awareness of the negative impact of poor metabolic control in adult life. Clinicians should consider implementing more intense and tailored educational measures, as well as structured transitional care processes.

Background: Lysosomal storage diseases (LSDs) are inborn errors of metabolism resulting from 50 different inherited disorders. The increasing availability of treatments and the importance of early intervention have stimulated newborn screening (NBS) to diagnose LSDs and permit early intervention to prevent irreversible impairment or severe disability. We present our experience screening newborns in North East Italy to identify neonates with Mucopolysaccharidosis type I (MPS I) and Pompe, Fabry, and Gaucher diseases., Methods: Activities of acid β-glucocerebrosidase (ABG; Gaucher), acid α-glucosidase (GAA; Pompe), acid α-galactosidase (GLA; Fabry), and acid α-L-iduronidase (IDUA; MPS-I) in dried blood spots (DBS) from all newborns during a 17-month period were determined by multiplexed tandem mass spectrometry (MS/MS) using the NeoLSD ® assay system. Enzymatic activity cutoff values were determined from 3500 anonymous newborn DBS. In the screening study, samples were retested if the value was below cutoff and a second spot was requested, with referral for confirmatory testing and medical evaluation if a low value was obtained., Results: From September 2015 to January 2017, 44,411 newborns were screened for the four LSDs. We recalled 40 neonates (0.09%) for collection of a second DBS. Low activity was confirmed in 20, who had confirmatory testing. Ten of 20 had pathogenic mutations: two Pompe, two Gaucher, five Fabry, and one MPS-I. The incidences of Pompe and Gaucher diseases were similar (1/22,205), with Fabry disease the most frequent (1/8882) and MPS-I the rarest (1/44411). The combined incidence of the four disorders was 1/4411 births., Conclusions: Simultaneously determining multiple enzyme activities by MS/MS, with a focus on specific biochemical markers, successfully detected newborns with LSDs. The high incidence of these disorders supports this screening program.

Unlabelled: The coexistence of two diseases associated with different metabolic disorders is a very rare event. Some associations, although sporadic, can be particularly challenging both in terms of diagnostic and therapeutic management and in terms of theoretical perspective. Here, we report a child affected by type 1 diabetes mellitus (T1DM) and glutaric aciduria type 1 (GA1). The child was diagnosed with classical T1DM at 15 months of age, with a tendency toward hypoglycemia. A few months later, during an acute intercurrent infective episode, the child displayed acute hypotonia of the lower limbs and limbs dystonia. A brain MRI showed bilateral striatal necrosis, suggesting GA1 diagnosis. Treatment with a low-lysine dietary regimen and carnitine supplementation was started and resulted in an improvement in metabolic control and a reduction of hypoglycemic episodes along with an increasing in insulin daily dose. After 2 years, the neurological outcome consisted of a reduction in dystonic movements and a metabolic stability of both diseases., Conclusion: This case provides some insight into the reciprocal interconnections between the two metabolic disorders. Similar pathogenic mechanisms responsible for the neuronal injury might have impacted each other, and a strict relationship between a specific aspect of GA1-impaired metabolism and glucose homeostasis might explain how the tailored management of GA1 was not only effective in controlling the disease, but it also resulted in an improvement in the control of the glycemic profile. What in known: • Glutaric aciduria type 1 (GA1) usually presents in childhood with severe and possibly irreversible neuronal damage, triggered by a catabolic stress • The association of GA1 with other diseases, including type 1 diabetes mellitus (T1DM), is a rare event, complicating the treatment management What is new: • Insulin treatment has a role in preventing GA1 metabolic decompensation, even in the catabolic condition of hypoglycemia • Promoting GA1 metabolic equilibrium by tailoring drug and dietary treatment in our patient affect by T1DM has a positive impact also in improving glycemic balance.

Background: The effect of long-term N-carbamylglutamate (NCG) treatment on the rate and severity of decompensations due to propionic aciduria (PA) and methylmalonic aciduria (MMA) is unknown. This paper presents clinical experience from a single-centre cohort of patients with PA and MMA who received continuous long-term treatment with NCG., Methods: The effect of oral NCG treatment (initial dose: 50 mg/kg/day) was investigated in patients with PA or MMA who were experiencing frequent progressive episodes of metabolic decompensation, who had pathological levels of ammonia, and who were referred to the Division of Metabolic Diseases, University Hospital of Padova between August 2014 and December 2015. Clinical and biochemical data, including the number of metabolic decompensations, lactic acid, uric acid and plasma ammonia levels, protein intake and body weight, were collected before and after the initiation of NCG treatment., Results: Eight patients with PA (n = 4) and MMA (n = 4) aged 2-20 years were treated with NCG (50 mg/kg/day) for 7-16 months. Metabolic decompensation episodes decreased in number and severity, with three of the patients having no episodes (pre-treatment: 24 episodes; post-treatment: 9 episodes). After NCG treatment, all episodes were treated at home and none required hospitalisation, lactic acid values were 1.3-2.1 mmol/L and uric acid values were 0.21-0.36 mmol/L. Significant reductions in blood ammonia levels after NCG initiation were observed in five patients, whereas levels were reduced or maintained in the normal range in the remainder. Over the treatment period, patients had an increase in natural protein intake of 20-50% and gained 0-6.5 kg in bodyweight., Conclusion: These observations suggest that, in addition to short-term benefits for the acute treatment of hyperammonaemia, NCG may be effective and well tolerated as a long-term treatment in patients with severe PA and MMA, and that further prospective studies are warranted.

Background: Phenylketonuria (PKU) is a chronic inborn error of amino acid metabolism that requires lifelong follow-up and intervention, which may represent strains on Quality of Life (QoL). This observational study evaluated QoL in a cohort of PKU patients, using updated and detailed instruments., Methods: 22 patients with mild PKU respondent to BH4 and 21 patients with classical PKU treated with diet were recruited in this study. Adult patients completed WHOQOL questionnaire-100 (WHOQOL-100) and pediatric patients the Pediatric QoL inventory (PedsQL(TM)). Psychiatric and mood disorders were also evaluated using TAD or BDI and STAI-Y inventories. A multivariable linear regression model was fitted to investigate the predictors of QoL, including age, sex, treatment type, length of current treatment, educational level and employment status (only for adults) as covariates. Results were presented as regression coefficients with 95% confidence interval., Results: Global QoL scores were within normal range both in patients with mild and classical disease but global QoL scores were significantly higher in patients with mild PKU under BH4 treatment as compared to those affected by classical disease who were under diet regimen. Furthermore, QoL significantly increased in long treated PKU patients. Among adult patients, QoL scores were significantly lower in males, in patients with lower education and in those employed or unemployed as compared to students (baseline)., Conclusions: Both diet and medical treatment based upon BH4 seem to be associated with higher QoL in the long run. However, patients with mild PKU can rely on BH4 to achieve a higher Phe tolerance and a better compliance to therapy due to diet relaxation/avoidance. Some specific categories of patients with a lower QoL should be investigated more in depth, engaging with those at risk of lower treatment compliance. The questionnaires employed in the present study seemed to be able to effectively detect criticalities in QoL assessment and represent an advance from previous inventories employed in the past.

We report the first case of late-onset isolated sulfite oxidase deficiency (ISOD) presenting with a stroke-like episode. Clinical, biochemical and neuroradiological features at diagnosis and during follow-up after dietary treatment intervention are described. Furthermore, pathogenic mechanisms possibly leading to stroke in ISOD are discussed., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Background: As advances in neonatal and pediatric care for patients affected by inherited metabolic diseases (IMD) improve their outcome and allow for better survival rates, there is a growing interest in the quality of life (QoL) of patients reaching adulthood. In order to address this subject we designed a study to evaluate the QoL of a group of adult IMD patients who are receiving various treatments, in a comprehensive manner., Methods: A mixed-method study was conducted to assess the QoL in adult IMD patients. The multidimensional World Health Organization Quality of Life questionnaire (WHOQOL-100) was applied for quantitative evaluations, and an additional semi-standardized interview, was conducted for qualitative measurement of patients' perceptions of the impact of illness on their daily life, and the perceived adherence to their treatment recommendations. A total of 82 patients affected by IMD were enrolled. The inherited metabolic disorders included principally amino acids disorders, urea cycle defects, organic acidurias, carbohydrates disorders, and lysosomal disorders. The WHOQOL-100 and the semi-standardized interview were administered in a clinical setting to adult patients with IMD., Results: The mean for the whole group indicates that adult patients with IMD can have a normal value of General QoL. Despite this value, the results of each domain show lower scores in the domains of perception of independence and quality of social relationships. We made a further analysis to compare the patients with dietary treatment with the patients with pharmacological treatment, and we observed a statistically significant difference in General QoL, in the Physical, Independence, Spiritual domains and in the facet of Medication. These results suggest that Global QoL measures might not be sufficient to assess the QoL for adult patients with IMD. Furthermore, the implementation of a qualitative semi-standardized interview, especially suitable for adult patients, added important features on illness perception and on perceived adherence to the treatment by adult IMD patients., Conclusion: In this study we underlined the importance of applying multidimensional instruments, like WHOQOL-100, to evaluate the quality of life of adult patients with IMD. The WHOQOL-100 has been demonstrated to be a valid instrument to measure the QoL of IMD patients. Moreover, the administration of a tailored psychometric instrument in combination with a qualitative interview may help us to better characterize special issues related to IMD. Indeed, other factors beyond the physical manifestations of the disease, such as psychological wellbeing, social behavior, illness perception and adherence to the treatment, strongly influence QoL and may serve as valid targets for intervention to improve patients' care. We believe this kind of approach is especially useful for adult patients with inherited metabolic diseases., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Pompe disease (PD) is a metabolic myopathy caused by a deficiency of acid-alpha glucosidase (GAA), a lysosomal enzyme that cleaves glycogen. The classic infantile-onset form is characterised by severe hypotonia and cardiomyopathy. Untreated patients usually die within the first year of life due to cardiorespiratory failure. Several studies involving patients with infantile-onset PD have shown that enzyme replacement therapy (ERT) with alglucosidase alfa, recombinant human GAA (rhGAA), significantly prolongs survival, decreases cardiomegaly, and improves cardiac function and conduction abnormalities. However, the efficacy on motor, cognitive and social milestones appears to be more related to the condition of the patient before the start of treatment. To date, the sample of early diagnosed and treated patients is small and the length of follow-up is still limited. We report the results of a long-term follow-up of one patient presenting severe bradycardia and cardiomyopathy at birth, diagnosed in the third day of life and successfully treated by ERT. Serum muscle enzymes at diagnosis were AST 200 U/L, ALT 99 U/L and CPK 731 U/L (n.v. 0-295); the molecular study identified the homozygous missense mutation c.1933 G> A p.Asp645Asn (GAA exon 14). Left Ventricular Mass Index (LVMI) at baseline was 171 g/m(2) (Z-score = 4.3) and decreased to normal values since the 3-month follow-up. A muscle biopsy performed at 18 months after the start of therapy, showed only a low degree of muscle involvement. To our knowledge, this is the longest ERT treatment follow-up in a symptomatic neonatal patient with Pompe disease.

Purpose: To evaluate the effect of agalsidase beta on longitudinal health-related quality of life in patients with Fabry disease., Methods: The SF-36® Health Survey was used to measure health-related quality of life in Fabry Registry patients. Seventy-one men and 59 women who were treated with agalsidase beta (median dose: 1.0 mg/kg/² weeks) and who had baseline and at least 2 yearly posttreatment health-related quality of life measurements were included in these analyses. A repeated measures model was used to analyze change in score from baseline., Results: Men improved in the physical component summary and in all eight scales of the SF-36 after 1 and 2 years and in the mental component summary after 1 year of agalsidase beta treatment (P < 0.05). Women improved in the mental component summary and in six of the eight scales after 1 and/or 2 years of treatment. Patients whose baseline SF-36 scores were below the median showed the greatest improvements. These responses were comparable with or greater than the published effects of various treatments for multiple sclerosis, rheumatoid arthritis, central neuropathic pain, and Gaucher disease., Conclusion: Long-term treatment with agalsidase beta resulted in substantial improvements in health-related quality of life in both men and women; the effect was more pronounced in men.