Publications by authors named "Santer R"

Objective: Maple syrup urine disease (MSUD), a life-threatening metabolic disorder, is included in newborn screening (NBS) programs worldwide. The study aims to evaluate the impact of NBS on the long-term outcome of MSUD patients.

Methods: We performed a prospective, national, multicenter, observational study.

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Together with its β-subunit OSTM1, ClC-7 performs 2Cl/H exchange across lysosomal membranes. Pathogenic variants in either gene cause lysosome-related pathologies, including osteopetrosis and lysosomal storage. CLCN7 variants can cause recessive or dominant disease.

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Renal proximal tubulopathy in Fanconi-Bickel syndrome is caused by impaired basolateral glucose transport via GLUT2 and consequently, intracellular accumulation of glucose and glycogen. SGLT2 inhibitors act on apical glucose reabsorption of renal proximal tubular cells. The purpose of this study was to retrospectively describe the first experiences with repurposing the SGLT2 inhibitor empagliflozin to treat the generalized tubulopathy in Fanconi-Bickel syndrome.

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Autosomal recessive pathogenetic variants in the gene cause deficiency of deoxyguanosine kinase activity and mitochondrial deoxynucleotides pool imbalance, consequently, leading to quantitative and/or qualitative impairment of mitochondrial DNA synthesis. Typically, patients present early-onset liver failure with or without neurological involvement and a clinical course rapidly progressing to death. This is an international multicentre study aiming to provide a retrospective natural history of deoxyguanosine kinase deficient patients.

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Background: Canavan disease is a devastating neurometabolic disorder caused by accumulation of N acetylaspartate in brain and body fluids due to genetic defects in the aspartoacylase gene (ASPA). New gene therapies are on the horizon but will require early presymptomatic diagnosis to be fully effective.

Methods: We therefore developed a fast and highly sensitive liquid chromatography mass spectrometry (LC-MS/MS)-based method for quantification of N-acetylaspartate in dried blood spots and established reference ranges for neonates and older controls.

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Objective: This study aims to elucidate the long-term benefit of newborn screening (NBS) for individuals with long-chain 3-hydroxy-acyl-CoA dehydrogenase (LCHAD) and mitochondrial trifunctional protein (MTP) deficiency, inherited metabolic diseases included in NBS programs worldwide.

Methods: German national multicenter study of individuals with confirmed LCHAD/MTP deficiency identified by NBS between 1999 and 2020 or selective metabolic screening. Analyses focused on NBS results, confirmatory diagnostics, and long-term clinical outcomes.

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Article Synopsis
  • - Pediatric acute liver failure (PALF) is a serious condition with up to 50% of cases remaining unexplained, hindering effective treatment options like liver transplantation.
  • - In a study involving 260 children from 19 countries, whole-exome sequencing (WES) identified genetic causes in 37% of indeterminate PALF cases, with a particularly high diagnostic rate in infants and those with recurrent liver failure.
  • - The research uncovered 36 distinct genes associated with PALF, highlighting mitochondrial diseases as the most common cause and underscoring the need for advanced genetic testing in diagnosing and treating this condition.
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Colour is a critical property of many traps used to control or monitor insect pests, and applied entomologists continue to devote time and effort to improving colour for greater trapping efficiency. This work has often been guided by human colour perceptions, which differ greatly from those of the pests being studied. As a result, trap development can be a laborious process that is heavily reliant on trial and error.

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Article Synopsis
  • Recessive variants in the NDUFAF3 gene are linked to serious mitochondrial disorders that often lead to severe neurological issues and early death in affected infants.
  • A case study of a 10-year-old patient presents atypical symptoms including neurodevelopmental disorders, progressive exercise intolerance, and high blood lactate levels, identified through advanced genetic analysis revealing specific pathogenic variants in NDUFAF3.
  • Investigations into mitochondrial function showed reduced complex I activity and unusual findings in mitochondrial complex assembly, contributing important new insights into the complexities of NDUFAF3-related mitochondrial diseases and highlighting the variability in patient symptoms.
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Newborn screening (NBS) allows early identification of individuals with rare disease, such as isovaleric aciduria (IVA). Reliable early prediction of disease severity of positively screened individuals with IVA is needed to guide therapeutic decision, prevent life-threatening neonatal disease manifestation in classic IVA and over-medicalization in attenuated IVA that may remain asymptomatic. We analyzed 84 individuals (median age at last study visit 8.

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Mucolipidosis type II (MLII), an ultra-rare lysosomal storage disorder, manifests as a fatal multi-systemic disease. Mental inhibition and progressive neurodegeneration are commonly reported disease manifestations. Nevertheless, longitudinal data on neurocognitive testing and neuroimaging lack in current literature.

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Diurnal biting flies are strongly attracted to blue objects. This behaviour is widely exploited for fly control, but its functional significance is debated. It is hypothesized that blue objects resemble animal hosts; blue surfaces resemble shaded resting places; and blue attraction is a by-product of attraction to polarized light.

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We report on liver transplantation in two patients with GSD Ib on treatment with empagliflozin. The use of this SGLT2 inhibitor resulted in a marked decrease of 1,5-anhydroglucitol which has an important role in the development of neutropenia in this condition. As intended, this caused a significant rise of neutrophil numbers.

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Article Synopsis
  • Superoxide dismutase-1 (SOD1) is an important antioxidant enzyme, and mutations in its gene can lead to amyotrophic lateral sclerosis (ALS) by causing toxic protein aggregation.
  • Researchers studied eight children with a specific mutation (p.C112Wfs*11) that resulted in SOD1 deficiency, finding that they experienced progressive motor neuron dysfunction and brain atrophy starting around 8 months of age.
  • Despite motor system deterioration, other organs showed normal integrity and resilience, indicating a unique vulnerability of the motor system to changes in SOD1 function.
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Newborn screening (NBS) for isovaleric acidemia (IVA) is performed by flow injection tandem mass spectrometry quantifying C5 carnitines (C5). Isovalerylcarnitine, however, is isomeric with pivaloylcarnitine which can be present in blood due to maternal use of pivaloylester-containing antibiotics, available in Germany since late 2016. During a 36-month period (January 19-December 21), all newborns screened in Hamburg with a C5 above cutoff (NeoGram®: 0.

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Hypophosphatasia (HPP) is an inherited, systemic disorder, caused by loss-of-function variants of the ALPL gene encoding the enzyme tissue non-specific alkaline phosphatase (TNSALP). HPP is characterized by low serum TNSALP concentrations associated with defective bone mineralization and increased fracture risk. Dental manifestations have been reported as the exclusive feature (odontohypophosphatasia) and in combination with skeletal complications.

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  • Regulation of hydrogen sulfide (HS) homeostasis in humans is not well understood, prompting a study of patients with rare enzyme deficiencies related to HS synthesis and catabolism.
  • Analysis of sulfur compounds in these patients revealed unexpected results, such as increased bioavailable sulfide levels in those with cystathionine β-synthase (CBS) deficiency, suggesting compensatory mechanisms at play.
  • The study highlights the complexity of HS regulation, showing that various genetic defects can lead to altered levels of sulfur compounds, underscoring the need for a thorough understanding of HS homeostasis in metabolic disorders.
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  • The study investigated the causes and effects of reversible acute liver failure (ALF) in infants due to harmful TRMU gene variants, focusing on the potential benefits of cysteine supplementation for treatment.
  • Among 62 individuals studied, 47 pathogenic TRMU variants were identified, with nearly all patients experiencing liver issues and many surviving beyond early childhood despite severe ALF cases in infancy, including some who underwent liver transplants.
  • Results indicated that liver failure was generally reversible in patients associated with TRMU variants, and cysteine supplementation significantly enhanced survival rates, although neurodevelopmental challenges persisted in some survivors.
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The SARS-CoV-2 pandemic challenges healthcare systems worldwide. Within inherited metabolic disorders (IMDs) the vulnerable subgroup of intoxication-type IMDs such as organic acidurias (OA) and urea cycle disorders (UCD) show risk for infection-induced morbidity and mortality. This study (observation period February 2020 to December 2021) evaluates impact on medical health care as well as disease course and outcome of SARS-CoV-2 infections in patients with intoxication-type IMDs managed by participants of the European Registry and Network for intoxication type metabolic diseases Consortium (E-IMD).

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Article Synopsis
  • Protein lipoylation is crucial for cell metabolism, with the H-protein (GCSH) playing a key role in this process for important enzymes and one-carbon metabolism.
  • A study of six patients with pathogenic variants in GCSH showed a range of clinical issues, from severe neonatal encephalopathy to milder developmental delays and movement disorders.
  • Functional analyses revealed that most mutations led to reduced mitochondrial activity and metabolic deficiencies, highlighting the importance of understanding these variants to guide treatment options.
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The mitochondrial malate aspartate shuttle system (MAS) maintains the cytosolic NAD+/NADH redox balance, thereby sustaining cytosolic redox-dependent pathways, such as glycolysis and serine biosynthesis. Human disease has been associated with defects in four MAS-proteins (encoded by , , , ) sharing a neurological/epileptic phenotype, as well as citrin deficiency () with a complex hepatopathic-neuropsychiatric phenotype. Ketogenic diets (KD) are high-fat/low-carbohydrate diets, which decrease glycolysis thus bypassing the mentioned defects.

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To prevent maternal phenylketonuria (PKU) syndrome low phenylalanine concentrations (target range, 120-360 μmol/L) during pregnancy are recommended for women with PKU. We evaluated the feasibility and effectiveness of current recommendations and identified factors influencing maternal metabolic control and children's outcome. Retrospective study of first successfully completed pregnancies of 85 women with PKU from 12 German centers using historical data and interviews with the women.

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Mucolipidosis (ML) type II, intermediate, and III are lysosomal storage disorders with progressive multiorgan manifestations predisposing patients to a high risk of perioperative morbidity. The aims of the study were to systematically assess disease manifestations relevant to anaesthesia as well as anaesthesia-related complications. This retrospective study includes ML patients who underwent anaesthesia in two centres between 2008 and 2022.

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