Search Results (76)

Background/Objectives: Inborn errors of metabolism (IEM) are chronic, life-threatening genetic disorders with a significant cumulative prevalence worldwide. Advances in early diagnosis and treatment have significantly increased life expectancy, underscoring the need for specialised adult care units and the establishment of structured transition programmes from paediatric to adult services. We hereby present a functional transition model for IEM patients and share our implementation experience. Methods: Initiated in 2012, the partnership between the paediatric Hospital Sant Joan de Déu (HSJD) and the adult-care centre at Hospital Clinic of Barcelona (HCB) culminated in 2019 with the transference of the first IEM patients under the structured A10! Programme. This model is structured around the transition units of paediatric and adult centres to guarantee communication and functional management. Regular monthly meetings at each centre and joint quarterly sessions allowed for protocol harmonisation and personalised care planning. Coordinated engagement of the multidisciplinary health care teams with patients and families smoothed the transfer process. Results: Between 2019 and 2024, 94 IEM patients were successfully transferred. Diagnoses included intermediary metabolism defects (71.23%), lipid metabolism and transport disorders (4.25%), heterocyclic compound metabolism (2.12%), complex molecules and organelle dysfunction (6.37%), cofactor and mineral metabolism (2.12%), signalling defects (5.31%), and unclassified cases (8.51% of rare disorders, maybe non-IEM). Transition formats included 21 in-person joint visits in HSJD, 37 remote transitions during the COVID-19 pandemic, and 36 streamlined transfers via standardised protocols. Sessions, trainings, and meetings allowed the exchange of patients’ needs and protocols. Conclusions: The successful transference of IEM patients requires structured programmes with interdisciplinary paediatric and adult teams, joining efforts with the patient, families, and caregivers. Communication between paediatric and adult transition units is essential to promote continuity of care and patient empowerment. While constantly updated, this model has proven effective, gaining positive evaluations from healthcare professionals and patients alike, representing a scalable framework for lifelong management of IEM in adult care settings. Full article

Background/Objectives: Phenylketonuria (PKU) is an inborn error of metabolism (IEM) that requires a specialized medical nutrition therapy (MNT) to maintain blood phenylalanine concentrations within a safe range. This study aimed to assess nutrition practices, knowledge, and PKU diet adherence in patients with PKU. Methods: This cross-sectional study included 27 patients (n = 19 women) with PKU, recruited from clinics of IEM in Greece, ranging in age between 14 and 60 years, with PKU diagnosis via neonatal screening. Each participant completed the questionnaire independently. For the two patients with age below 18 years old, caregivers provided written informed consent. All participants were questioned regarding their dietary practices, nutritional knowledge, and perceptions. Results: More than half (66.7%) of patients complied with the PKU diet and the recommended daily protein substitutes. However, 25.9% reported being unaware of their blood phenylalanine levels, and 40.7% didn’t know how many PKU exchanges they consumed daily. Most patients (88.8%) perceived the recommended PKU diet as “healthy”, and reported feeling well when adhering to it. Several concerns were raised regarding protein substitutes, with 10.5% of patients feeling that the amount of prescribed protein substitutes was too high, while 25.9% perceived it as being too low. Additionally, 14.8% of patients expressed concerns regarding the protein amount required for building muscle mass. Overall, the majority of participants perceived the PKU diet as being adequate in energy, carbohydrates, lipids, and protein. Conclusions: Although patients with PKU generally possess a good understanding of PKU nutritional principles, significant potential for improvement in dietary education is apparent. To support optimal management of blood phenylalanine concentrations, it is essential to implement novel communication strategies that facilitate patient adherence to the MNT for PKU. Such strategies should also empower caregivers to provide effective support, including the proper use of protein substitutes and accurate protein exchanges. Full article

Background/Objectives: The transition from pediatric to adult care in inborn errors of metabolism (IEM) is considered important to ensure continuity of care, adherence to treatment, and long-term metabolic control. However, transition processes are often delayed, and standardized protocols are lacking, which can negatively impact patient outcomes. This study aimed to evaluate the impact of structured transition consultations on adult care engagement, nutritional management, and follow-up adherence in patients with IEM. Methods: This retrospective study included 160 patients (59.4% women) diagnosed with IEM and with a mean age of 36.2 ± 11.6 years. Patients were divided into two groups: those who underwent a structured transition consultation (n = 41) and those who did not (n = 119). Data on demographic and clinical characteristics, dietary management, and follow-up adherence were collected. Results: Patients who underwent structured transition consultations were significantly younger at diagnosis (1 [IQR 131] months vs. 66 [IQR 359] months, p = 0.001) and at their first adult visit (24.4 ± 9.5 vs. 32.3 ± 10.6 years, p < 0.001) compared to those who did not. Neonatal screening (45% of the overall cohort) was more common among these patients (65.9% vs. 37.8%, p = 0.007) suggesting a trend toward smoother integration into adult care. The absence of dietary records was considerably more frequent in the non-transition group (43.7% vs. 17.1%), with a significant crude association (p = 0.007) that was attenuated after age adjustment (p = 0.064). Overall follow-up adherence was high (88.1%) and comparable between groups. Conclusions: Structured transition consultations in patients with IEM were associated with earlier participation in adult care, better maintenance of dietary records, and high overall follow-up adherence, even among younger patients typically at higher risk of disengagement. Full article

Background: The primary treatment for inborn errors of metabolism (IEM) involves restricted intake of natural protein. Inadequate diets can lead to an increased risk of inflammation and susceptibility to infections. The Dietary Inflammatory Index (DII) is used to estimate whether a diet has anti-inflammatory or pro-inflammatory properties. This study aimed to investigate the relationship between the inflammatory index score of natural protein-restricted diets used in medical nutrition therapy for IEM intoxication, the anthropometric measurements and nutritional status of affected children. Method: The study included 20 patients (5 organic acidemia, 5 urea cycle disorders, 10 phenylketonuria) and 20 healthy children. Patients followed a natural protein-restricted diet, while the healthy control group maintained their usual dietary habits. Dietary records were collected for both groups, and the DII and macro-micronutrient intakes were calculated. Result: DII scores were similar between the patient and control groups. Anthropometric measurements did not differ significantly between the groups. However, carbohydrate and fat intakes were higher in the patient group compared to the control group (p < 0.05). Additionally, comparative analyses revealed that vitamin B1, C and E, iron, and magnesium intakes were higher in the patient group than in the control group. Conclusions: Children on a natural protein-restricted diet showed growth patterns comparable to their healthy peers. This study demonstrated that nutritional deficiencies can be prevented in amino acid metabolism disorders treated with a natural protein-restricted diet by carefully controlling nutrition with vitamin and mineral-fortified formulas. Full article

Organic acidurias, a subgroup of inborn errors of metabolism (IEMs), are characterized by the accumulation of non-amine-containing, low-molecular-weight organic acids (OAs) in urine and/or plasma due to defects in specific metabolic pathways. Early diagnosis can be critical to enable timely intervention to prevent irreversible neurological injury or death. Therefore, urine organic acid (UOA) testing plays an indispensable role in the differential diagnosis of symptomatic individuals and the follow-up of abnormal newborn screen results. Historically, gas chromatography-mass spectrometry (GC-MS) has been the gold standard method, with well-established protocols for sample preparation and result interpretation. Recent advances in liquid chromatography-mass spectrometry (LC-MS), including both triple quadrupole and high-resolution Quadrupole Time-of-Flight (QTOF) platforms, have enabled UOA analysis with simplified workflows and improved coverage to diagnose a broader array of IEMs. This review summarizes the evolution of UOA testing from manual colorimetric assays to mass spectrometry-based platforms, highlights the analytical and interpretative considerations of GC-MS, and explores emerging LC-MS technologies and bioinformatics tools that offer enhanced diagnostic capabilities and efficiency for the future of IEM testing. Full article

Acetoacetyl-CoA thiolase deficiency, also known as Beta-ketothiolase deficiency (BKTD), is an autosomal recessive organic aciduria included in the Italian newborn screening (NBS) panel. It is caused by mutations in the ACAT1 gene, which encodes the mitochondrial acetyl-CoA acetyltransferase. Its deficiency impairs the degradation of isoleucine and acetoacetyl-CoA, leading to the accumulation of toxic metabolites. We describe three cases of BKTD. The first newborn showed increase in C5:1, C4DC/C5OH, C3DC/C4OH in the NBS. Urinary organic acids (uOAs) revealed marked excretion of 2-methyl-3-hydroxybutyrate. Tiglylglycine was absent. Genetic testing identified the compound heterozygosity for two pathogenic ACAT1 variants. The second patient showed increased levels of C5:1, C4DC/C5OH, C3DC/C4OH in the NBS. uOAs revealed 2-methyl-3-hydroxybutyrate and tiglylglycine. A homozygous VUS in ACAT1 was identified. The third case showed elevation of C4DC/C5OH, C3DC/C4OH in the NBS, with a slight increase in C5:1. uOAs showed 2-methyl-3-hydroxybutyrate and tiglylglycine. A homozygous missense VUS was identified in the ACAT1 gene. BKTD exhibited variable NBS biochemical phenotypes across the three cases. While C5OH and C5:1, the primary markers, were not consistently elevated in all our cases, C4OH strongly increased in all three. Our findings support the use of C4OH in a combined marker strategy to improve BKTD NBS. Full article

Sweden has one neonatal screening laboratory and two centers conducting diagnostic workup for inborn errors of metabolism (IEM). Next-generation sequencing (NGS) has been gradually introduced as a confirmatory diagnostic test in the Swedish newborn screening program. Here, we describe the use of NGS in the diagnostic workup of IEM in screening-detected babies in Sweden between 2015 and 2023. During this period, 1,023,344 newborn children were screened, and 81 of 290 IEM cases were genetically confirmed using NGS. Planned improvements to the program are to perform genetic validation directly on the initial dried blood spot (DBS). As whole-genome sequencing (WGS) is superior in detecting causative genetic variants compared to Sanger sequencing, targeted NGS, and whole-exome sequencing (WES), it will likely become the method of choice more broadly in the future. A strong focus is to consolidate the nationally coordinated DBS newborn screening program, with all its individual components, including screening, targeted diagnostics, individualized treatment, and follow-up. This challenges the current regionalized organization of Swedish healthcare, which hinders close national collaboration between experts and sharing of data, as well as equal access to advanced treatments for identified patients, regardless of their place of birth. Full article

In Brazil, dried blood spots (DBSs) for newborn screening (NBS) should be collected between the 3rd and 5th days of life at local Basic Health Units (BHUs). This study reports the experience of face-to-face training at BHUs in southern Brazil during a pilot study for tandem mass spectrometry (MS/MS) inclusion in the NBS program. The pilot project involved screening for 22 inborn errors of metabolism (IEMs). The professionals at the BHUs were instructed to carry out the following: (a) explain the study to parents or guardians; (b) collect additional DBS samples on a different collection card (research card); and (c) deliver results to families. In-person visits were conducted at all 137 BHUs. These visits included an overview of the pilot project and distribution of educational materials, including a list of the 22 IEMs and informational leaflets on MS/MS-based NBS. Among the 486 healthcare professionals who participated, 91.2% were women. Overall, 97.1% of the BHUs reported being satisfied with the project. Questions regarding IEMs were raised in 40.1% of BHUs, and 13.1% reported complaints about the research card due to its lighter texture and drying difficulty. Training primary healthcare professionals in IEMs remains an urgent priority in Brazil, particularly in the context of expanded NBS using MS/MS, since they are the frontline professionals in the NBS program. Full article

Background: Newborn screening is an essential public health strategy that aims to detect a range of conditions, including inborn errors of metabolism, in neonates shortly after birth. The timely identification is crucial due to the asymptomatic nature of many conditions at birth, but which can lead to significant health complications if left untreated. Through this study, we aimed to investigate the incidence of IEMs screened by the Qatar National Newborn Screening Program. Methods: We retrospectively analyzed a total of 351,223 newborns screened from 2010 to 2023. The incidence for the studied IEMs was calculated and correlated with demographics, consanguinity, and family history. In addition, the diagnostic yield of different tests utilized was assessed. Results: Our study revealed a total of 318 positive cases with IEMs, and a significantly high incidence of 1:1105 for IEMs in Qatar. Classical Homocystinuria was the most frequently detected condition, with a cumulative incidence of 1:6754 live births, linked to the founder variant p. Arg336Cys in the CBS gene. Aminoacidopathies were the most prevalent category, followed by fatty acid oxidation disorders, organic acidurias, biotinidase deficiency, and urea cycle disorders. Genetic testing showed a high diagnostic yield of 90%. Of the 60 cases that underwent targeted variant testing, 98% were confirmed, while 90% of the 59 cases tested by single gene testing were confirmed. Conclusions: Our study provides the incidence rates of IEMs in Qatar and novel insights that could facilitate setting up/developing IEM incidence-reducing strategies and improving outcomes for affected newborns and their families. Full article

Background: The advent of tandem mass spectrometry (MS/MS) had an essential role in the expansion of newborn screening (NBS) for different inborn errors of metabolism (IEMs). Nowadays, almost 50 IEMs are screened in Italy. The use of second-tier tests (2-TTs) in NBS minimizes the false positive rate; nevertheless, the metabolic profile is influenced not only by the genome but also by environmental factors and clinical variables. We reviewed the MS/MS NBS data from over 37,000 newborns (of which 8% required 2-TTs) screened in the Italian Abruzzo region to evaluate the impact of neonatal and maternal variables on propionate-related primary biomarker levels. Methods: Expanded NBS and 2-TT analyses were performed using MS/MS and liquid chromatography–MS/MS methods. We set up layered cut-offs dividing all 37,000 newborns into categories. Statistical analysis was used to create alarm thresholds for NBS-positive samples. Statistically significant differences were found in both neonatal and maternal conditions based on the 2-TTs carried out. According to the stratified cut-offs, only 1.47% of the newborns would have required a 2-TT while still retaining the ability to recognize the true-positive case of methylmalonic acidemia with homocystinuria, which has been identified by NBS. To further support the clinical applicability, we performed an external evaluation considering nine positive cases from an extra-regional neonatal population, confirming the potential of our model. Interestingly, the setting of alarm thresholds and their application would allow for establishing the degree of priority/urgency for 2-TTs. Conclusions: Tailoring NBS by customized cut-offs may enhance the application of precision medicine, focusing on true-positive cases and also reducing analysis costs and times. Full article

Inborn errors of metabolism (IEMs) are a group of disorders resulting from defects in enzymes in metabolic pathways. These disorders impact the processing of metabolites, leading to a wide array of effects on each organ system. Advances in genetic screening have allowed for the early identification and intervention of IEMs, traditionally in the form of enzyme replacement or vitamin supplementation. However, many IEMs disrupt essential metabolic pathways where simple supplementation proves ineffective, resulting in substantial disease burden. In the case of renal IEMs, metabolic pathway disruption leads to the onset of chronic kidney disease (CKD). For these diseases, genetic therapy provides hope. Over the past few decades, the technology for genetic therapy has emerged as a promising solution to these disorders. These therapies aim to correct the source of the defect in the genetic code so that patients may live full, unencumbered lives. In this review, we searched a large database to identify IEMs that affect the kidney and investigated the current landscape and progression of gene therapy technology. Multiple promising genetic therapies were identified for IEMs affecting the kidney, including primary hyperoxaluria, argininemia, glycogen storage diseases Ia and Ib, and Fabry disease. Emerging gene therapy approaches using adeno-associated virus (AAV) vectors, lentiviral vectors, and CRISPR/Cas9 techniques hold promising potential to provide curative treatments for additional single-mutation disorders. Full article

Newborn Bloodspot Screening (NBS) can detect severe treatable health conditions with onset during infancy. The parents of a newborn baby are vulnerable in the days after birth, and the optimal way to deliver the shocking and distressing news of a potential serious diagnosis is yet to be defined. More data are needed to determine whether access to a genetic counsellor (GC) improves families’ experiences with genetic conditions identified by NBS. This study aimed to explore the similarities and differences for parents who received a positive NBS result for Spinal Muscular Atrophy (SMA) and received access to a GC (GC cohort), to a cohort of parents who received a diagnosis for inborn errors of metabolism (IEM) and did not have access to a GC (non-GC cohort). Semi-structured interviews explored the retrospective experiences of receiving the NBS result, including diagnosis implications and subsequent adaptation to respective genetic diagnoses. Inductive thematic analysis was used from group comparison. 7 SMA families and 5 IEM families were included in the study. Four themes were identified: 1. minimal pre-test counselling; 2. perceived lack of local healthcare team knowledge; 3. enabling factors for adaptation; 4. implications for both individuals and their families. Both the GC and non-GC cohorts reported insufficient counselling in the pre-test period and described feeling traumatised at the time of the diagnosis delivery. Families without subsequent GC input described limited understanding of the disease due to the use of medicalized terms, as well as a decreased understanding of reproductive options, familial communication and subsequent cascade screening. GCs can support information needs and adaptation following a NBS diagnosis. Full article

Background: Newborn screening (NBS) is a preventive healthcare program aiming at identifying the inborn errors of metabolism (IEMs) in asymptomatic infants to reduce the risk of severe complications. The aim of this study was to report the first years (2016–2020) of the expanded NBS program in the Lombardy region, Italy. Methods: Dried blood spots were collected from newborns’ heels at 48–72 h after birth. FIA-MS/MS was performed to evaluate specific biochemical markers. Genetic confirmation was achieved via Sanger or NGS on newborns and reported to a clinical reference center (CRC). Results: A total of 343,507 newborns were tested; 1414/343,507 resulted as positive to NBS and were reported to the CRC. A total of 209 newborns were diagnosed with IEMs: 206 infants received a diagnosis of IEM through NBS, confirmed by genetic analysis; three neonates were not positive to NBS but were subsequentially diagnosed with IEMs. A total of 1208/343,507 were false positive cases. Twenty-seven types of IEMs were diagnosed in 209 patients: 111 newborns were affected by aminoacidemias, 11 by urea cycle disorders, 27 by organic acidemias, 34 by fatty acid oxidation disorders, and 26 by secondary conditions. Conclusions: We report here for the first time the IEM incidence and distribution in the Lombardy region in the first five years of NBS. Full article

Expanded newborn screening (NBS) programs are essential for early detection and treatment. This study highlights the implementation of an expanded NBS program for inborn errors of metabolism (IEMs) and congenital hypothyroidism (CH) in rural Thailand, focusing on Health Regions 7 and 8 as a model for resource-limited settings. Using the KKU-IEM web-based platform, the program streamlined workflows, integrating logistics, real-time sample tracking, and electronic data management. Regular training sessions, continuous feedback, and systematic monitoring improved outcomes. Starting from October 2022, the program covered 98.6% of 123,692 live births, identifying 101 CH cases (1 in 1208 live births) and 20 IEM cases (1 in 6100 live births). The CH incidence was slightly higher than Thailand’s national average, while the IEM incidence was double that found in a previous Bangkok pilot study. Six cases highlighted maternal conditions affecting outcomes. Process improvements reduced the average reporting time from 9.13 days in 2023 to 8.4 days in 2024, with a 19% reduction in Bueng Kan Province. Efficiencies were driven by electronic ordering, real-time tracking, and stakeholder collaboration. This program demonstrates a scalable model for rural settings, emphasizing technology integration, collaboration, and quality control. Future efforts should refine diagnostics, expand disease coverage, and enhance long-term outcomes. Full article

Background/Objectives: Inborn errors of metabolism (IEMs) represent a diverse group of genetic disorders characterized by enzymatic defects that disrupt metabolic pathways, leading to toxic metabolite accumulation, deficits, or impaired macromolecule synthesis. While strict dietary interventions are critical for managing many of these conditions, hormonal and metabolic changes during puberty introduce new challenges. Advancements in early diagnosis and treatment have significantly extended the lifespan of individuals with IEMs. However, this increased longevity is associated with heightened risks of new medical problems, including obesity, insulin resistance, and type 2 diabetes mellitus (T2DM), as these complications share mechanistic features with those seen in obesity and T2DM. Methods: This mini-review examines current knowledge of the intricate interplay between pubertal hormones and metabolic pathways in IEM patients. Results: We address critical questions, such as if puberty intensifies the risk of metabolic derangements in these individuals and if there is a metabolic intersection where these disorders converge, leading to shared complications. We highlight the impact of puberty-induced hormonal fluctuations, such as growth hormone (GH) surges and sex steroid activity, on disorders like phenylketonuria, urea cycle defects, and fatty acid oxidation disorders. Moreover, we explore the role of dietary interventions in mitigating or exacerbating these effects, emphasizing the importance of balancing nutritional needs during growth spurts. Conclusions: A multidisciplinary approach integrating endocrinology, nutrition, and emerging therapies is advocated to optimize metabolic health during puberty. Addressing these challenges is critical for improving long-term outcomes for individuals with IEMs, particularly during this pivotal developmental phase. Full article