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Fabiano de Oliveira Poswar,1– 4 Johanna Henriques Nehm,1 Francyne Kubaski,5 Edina Poletto,6 Roberto Giugliani1– 4,7– 9 1Clinical Research Group in Medical Genetics, Clinical Research Center, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brazil; 2Medical Genetics Service, Hospital de Clinicas de Porto Alegre, Porto Alegre, RS, Brazil; 3Postgraduate Program in Genetics and Molecular Biology, UFRGS, Porto Alegre, RS, Brazil; 4DR Brasil Research Group, HCPA, Porto Alegre, RS, Brazil; 5Greenwood Genetic Center, Biochemical Genetics Laboratory, Greenwood, SC, USA; 6Department of Pediatrics, Stanford University School of Medicine, Stanford, CA, USA; 7Department of Genetics, UFRGS, Porto Alegre, RS, Brazil; 8DASA Genômica, São Paulo, SP, Brazil; 9Casa dos Raros, Porto Alegre, RS, BrazilCorrespondence: Roberto Giugliani, Medical Genetics Service- HCPA / Dep Genet UFRGS, 2350 Ramiro Barcelos, Porto Alegre, RS, 90035-903, Brazil, Tel +55 51 3359 6338, Email rgiugliani@hcpa.edu.brAbstract: Mucopolysaccharidosis VII (MPS VII, Sly syndrome) is an ultra-rare lysosomal disease caused by a deficiency of the enzyme β-glucuronidase (GUS). The diagnosis is suspected based on a range of symptoms that are common to many other MPS types, and it is confirmed through biochemical and molecular studies. Besides supportive treatment, current and emerging treatments include enzyme replacement therapy, hematopoietic stem cell transplantation, and gene therapy. This review summarizes the clinical manifestations, diagnosis, and emerging treatments for MPS VII.Keywords: lysosomal disorders, mucopolysaccharidosis type VII, Sly syndrome, enzyme replacement therapy, hematopoietic stem cell transplantation, gene therapy

Measurement of enzymatic activity in newborn dried blood spots (DBS) is the preferred first-tier method in newborn screening (NBS) for mucopolysaccharidosis (MPS) disorders. However, false positives are observed due mainly to the presence of pseudodeficiencies. Our previous publications on glycosaminoglycan (GAG) biomarker levels in dried blood spots (DBS) for mucopolysaccharidoses demonstrated that second-tier GAG biomarker analysis can dramatically reduce the false positive rate in NBS. In the present study, we extend this approach to the analysis of a large number of false positives for MPS-I obtained from the Illinois, New York, and Tennessee NBS programs and from Greenwood Genetics Center. Results show that GAG levels measured by the Endogenous-Non-Reducing End method (Endogenous-NRE) are in the normal reference range for all samples. In a second study, we analyzed 166 samples that showed below-cutoff MPS-I enzymatic activity level after testing 384,144 newborns in the Ontario, Canada NBS program. Both genotype and Endogenous-NRE GAG levels were determined for all 166 samples. Newborns at high risk for MPS-I based on genotype also showed elevated GAG levels and were clinically confirmed to be symptomatic for MPS-I. All newborns with pseudodeficiency or carrier status by genotyping all showed normal levels of the appropriate GAG biomarker. Samples found to be inconclusive based on one or more variants of unknown significance (VUS) all showed normal GAG biomarker levels and were found to be clinically normal during follow-up. These studies show that the Endogenous-NRE GAG second-tier NBS method is preferred over second-tier DNA analysis for the NBS of MPS-I with minimal false positives., Competing Interests: Declaration of competing interest Z.M.H. is a member of GelbChem, LLC. M.H.G. is a co-founder and member of GelbChem, LLC. The other authors declare no conflicts of interest., (Crown Copyright © 2024. Published by Elsevier Inc. All rights reserved.)

Geographic and sociodemographic aspects may influence the natural history and epidemiology of mucopolysaccharidoses (MPS). The main objective in this work was to evaluate the clinical, molecular, and geographic profile of MPS in a population from Ceará (Northeast Brazil). For this, we have performed a descriptive cross-sectional study based on clinical evaluation, interviews with patients and/or family members, and review of medical records of 76 MPS patients. MPS II was the most common type, with the most affected individuals presenting missense pathogenic variants. Patients with MPS I proved to be the most severe clinical phenotype, presenting the first symptoms (mean: 7.1 months; SD = 4.5) and being diagnosed earlier (2.2 years; SD = 2.1) in comparison with the other types. In addition, we have shown that 13 individuals with MPS VI were born of consanguineous marriages in small, nearby cities, in a place where geographical isolation, consanguinity, and clusters of genetic diseases were previously reported. Ten of these individuals (at least, seven different families) presented a rare pathogenic variant in the ARSB gene, c.1143-8T > G in homozygosity, previously reported only among Iberian and South American patients. The results presented here provide a comprehensive picture of MPS in an important state of the Brazilian Northeast, a region that concentrates many risk factors for rare genetic diseases, such as endogamy, inbreeding, and reproductive isolation. We discuss the possible evolutionary processes and biosocial dynamics that can help to explain this finding in terms of population medical genetics and public health., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Mucopolysaccharidosis type IIIB (MPS IIIB) is caused by deficiency of alpha-N-acetylglucosaminidase, leading to storage of heparan sulphate. The disease is characterized by intellectual disability and hyperactivity, among other neurological and somatic features. Here we studied retrospective data from a total of 19 MPS IIIB patients from Brazil, aiming to evaluate disease progression. Mean age at diagnosis was 7.2 years. Speech delay was one of the first symptoms to be identified, around 2-3 years of age. Behavioral alterations include hyperactivity and aggressiveness, starting around age four. By the end of the first decade, patients lost acquired abilities such as speech and ability to walk. Furthermore, as disease progresses, respiratory, cardiovascular and joint abnormalities were found in more than 50% of the patients, along with organomegaly. Most common cause of death was respiratory problems. The disease progression was characterized in multiple systems, and hopefully these data will help the design of appropriate clinical trials and clinical management guidelines.

Gaucher disease (GD, OMIM 230800) is one of the most common lysosomal disorders, being caused by the deficient activity of the enzyme acid β-glucocerebrosidase (Gcase). Three clinical forms of Gaucher's disease (GD) are classified based on neurological involvement. Type 1 (GD1) is non-neuronopathic, while types 2 (GD2) and 3 (GD3) are neuronopathic forms. Gcase catalyzes the conversion of glucosylceramide (GlcCer) into ceramide and glucose. As GlcCer accumulates in lysosomal macrophages, it undergoes deacylation to become glycosylsphingosine (lyso-Gb1), which has shown to be a useful and reliable biomarker for the diagnosis and monitoring of treated and untreated patients with GD. Multiple myeloma (MM) is one of the leading causes of cancer-related death among patients with GD and monoclonal gammopathy of undetermined significance (MGUS) is a non-neoplastic condition that can be a telltale sign of a B clonal proliferation caused by the chronic activation of B cells. This study aimed to quantify Lyso-Gb1 levels in dried blood spots (DBS) and cerebrospinal fluid (CSF) as biomarkers for Gaucher disease (GD) and discuss the association of this biomarker with other clinical parameters. This is a mixed-methods study incorporating both cross-sectional and longitudinal elements within a cohort design with a convenience-sampling strategy. Data collection took place from January 2012 to March 2023. Lyso-Gb1 extraction from DBS involved the use of a methanol-acetonitrile-water mixture, followed by incubation and centrifugation. Analysis was performed using UPLC-MS/MS with MassLynx software version 4.2 and the control group for the DBS measurements included general newborns. CSF Lyso-Gb1 was extracted using ethyl acetate, analyzed by UPLC-MS/MS with a calibration curve, and expressed in pmol/L. Lysosomal activity in CSF was assessed by measuring chitotriosidase (Cht), and other lysosomal enzyme activities were assessed as previously described in the literature. Patients with metachromatic leukodystrophy (MLD) were used as controls. Thirty-two treated patients (twenty-nine GD1 and three GD3, all on ERT except for one GD type on SRT with eliglustat) and three untreated patients (one GD1, one GD2, and one GD3) were included. When analyzing only the treated GD1 group, a significant correlation was found between lyso-Gb1 and age (rho = -0.447, p = 0.001), ChT, and IgG levels (rho = 0.73, p < 0.001; and rho = 0.36, p = 0.03, respectively). Five GD1 patients (three females, mean age 40 years) also had their CSF collected and analyzed. The average measurement of lyso-Gb1 in CSF was 94 pmol/L (range: 57.1-157.9 pmol/L) versus <6.2 pmol/L in the control group (MLD). This is the first time, to the best of our knowledge, that lyso-Gb1 has been associated with IgG levels. While this finding reflects a risk for MGUS or MM and not only chronic plasma B-cell activation, it still requires further studies. Moreover, the analysis of CSF lyso-Gb1 levels in GD1 patients was demonstrated to be significantly higher than the control group. This raises the hypothesis that CSF lyso-Gb1 may serve as a valuable indicator for neurological involvement in GD, providing insights into the potential implications for neurological manifestations in GD, including GD1. The correlation between lyso-Gb1 and ChT levels in treated GD1 patients further underscores the interconnectedness of lysosomal markers and their relevance in monitoring.

Background and Aim: Mucopolysaccharidosis type III (MPS III) is a rare autosomal recessive lysosomal storage disease (LSD) caused by a deficiency of lysosomal enzymes required for the catabolism of glycosaminoglycans (GAGs), mainly in the central nervous system. Trehalose has been proposed as a potential therapeutic agent to attenuate neuropathology in MPS III. We conducted a single- arm, open-label study to evaluate the efficacy of trehalose treatment in patients with MPS IIIA and MPS IIIB., Methods: Five patients with MPS III were enrolled. Trehalose was administrated intravenously (15 g/week) for 12 weeks. Health-related quality of life and cognitive function, serum biomarkers, liver, spleen, and lung imaging were assessed to evaluate trehalose efficacy at baseline and trial end (week 12)., Results: TNO-AZL Preschool children Quality of Life (TAPQOL) scores increased in all patients, and the mean scores for quality of life were increased after the intervention. Serum GAG levels were reduced in all treated patients (however, the differences were not statistically significant). Alanine aminotransferase (ALT) levels were reduced in all patients post-treatment (p=0.0039). The mean levels of aspartate transaminase (AST) were also decreased after 12 weeks of treatment with Trehalose. Decreased serum pro-oxidant-antioxidant balance and increased GPX activity were observed at the end of the study. Decreases in mean splenic length were observed, whereas the liver volume did not change., Conclusion: Improvements in health-related quality of life and serum biomarkers (GAGs, liver aminotransferase levels, antioxidant status), as well as liver and spleen size, were found following 3 months of trehalose administration in patients with MPS IIIA and MPS IIIB., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Background: Parkinson's disease (PD) is the second most common neurodegenerative disease worldwide. Its classic motor symptoms may be preceded by non-motor symptoms (NMS). Population studies have identified GBA variants as risk factors for idiopathic PD. The increased risk of PD has also been suggested in other Lysosomal Storage Disorders (LSDs)., Objective: To assess the evolution of the prevalence of NMS compatible with PD in a cohort of South Brazilian adult patients with Gaucher Disease (GD) type 1, already evaluated 3 years ago (2018). Cerebrospinal Fluid (CSF) was collected to assess the levels of LSD enzymes (beta-hexosaminidases, beta-glucuronidase) and biomarker of macrophage activation (chitotriosidase, ChT), compared to controls (metachromatic leukodystrophy, MLD). Cognition was evaluated by the Montreal Cognitive Assessment (MoCA) questionnaire, daytime sleepiness by the Epworth Sleepiness Scale (ESS), depression by Beck´s Inventory, constipation by the Unified Multiple System Atrophy Rating Scale (UMSARS) scale, and REM sleep behavior disorder by the single-question screen. Hyposmia was assessed with Sniffin' Sticks (SST)., Results: Nineteen patients completed the follow-up (mean age of the sample was 44 years; range, 26-71). The patient with the highest number of NMS at the baseline (4 including the lowest SST score) was diagnosed with PD four years later. Apart from an improvement in the ESS score, no other statistical significance was found between the number of NMS between the first and second evaluation, nor between patients with one L444P variant (n = 5) and the rest of the cohort. CSF was collected in five patients (mean age of the sample was 40 years, range 30-53. A significant difference was found in the mean CSF activity levels of beta-hexosaminidases and beta-glucuronidase between GD1 and MLD patients. Mean ChT (CSF) was 62 nmol/h/mL in GD patients and 142 in MLD (n = 6) patients., Conclusions: The patient with the highest number of NMS in our 2018 cohort was the one that developed PD, corroborating with the importance of this longitudinal follow-up. CSF and plasma analysis might allow a better understanding of the neurodegenerative processes connecting PD and the lysosomal environment. Further analysis is needed to understand this relationship., (© 2023. Institut National de la Santé et de la Recherche Médicale (INSERM).)

Background: Lysosomal diseases (LDs) are progressive life-threatening disorders that are usually asymptomatic at birth. Specific treatments are available for several LDs, and early intervention improves patient's outcomes. Thus, these diseases benefit from newborn screening (NBS). We have performed a pilot study for six LDs in Brazil by tandem mass spectrometry., Methods: Dried blood spot (DBS) samples of unselected newborns were analyzed by the Neo-LSD™ kit (Perkin-Elmer) by MS/MS. Samples with low enzyme activity were submitted to the evaluation of specific biomarkers by ultra-performance liquid chromatography tandem-mass spectrometry as the second-tier, and were analyzed by a next-generation sequencing (NGS) multi-gene panel as the third-tier. All tests were performed in the same DBS sample., Results: In 20,066 newborns analyzed, 15 samples showed activity of one enzyme below the cutoff. Two newborns had biochemical and molecular results compatible with Fabry disease, and five newborns had biochemical results and pathogenic variants or variants of unknown significance (VUS) in GAA., Conclusions: This study indicates that the use of enzyme assay as the first-tier test gives an acceptably low number of positive results that requires second/third tier testing. The possibility to run all tests in a DBS sample makes this protocol applicable to large-scale NBS programs., Competing Interests: Declaration of Competing Interest The authors declare no confliefhe writing of the manuscript, or in the decision to publish the results., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Measurement of enzymatic activity in newborn dried blood spots (DBS) is the preferred first-tier method in newborn screening (NBS) for mucopolysaccharidoses (MPSs). Our previous publications on glycosaminoglycan (GAG) biomarker levels in DBS for mucopolysaccharidosis type 1 (MPS-I) and MPS-II demonstrated that second-tier GAG biomarker analysis can dramatically reduce the false positive rate in NBS. In the present study, we evaluate two methods for measuring GAG biomarkers in seven MPS types and GM1 gangliosidosis. We obtained newborn DBS from patients with MPS-IIIA-D, -IVA, -VI, -VII, and GM1 gangliosidosis. These samples were analyzed via two GAG mass spectrometry methods: (1) The internal disaccharide biomarker method; (2) The endogenous non-reducing end (NRE) biomarker method. This study supports the use of second-tier GAG analysis of newborn DBS by the endogenous NRE biomarker method, as part of NBS to reduce the false positive rate., Competing Interests: Declaration of Competing Interest Z.M.H. is a member of GelbChem, LLC. M.H.G. is a co-founder and member of GelbChem, LLC. The other authors declare no conflicts of interest., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Tandem mass spectrometry (MS/MS) is the most universal platform currently available for the analysis of enzymatic activities and biomarkers in dried blood spots (DBS) for applications in newborn screening (NBS). Among the MS/MS applications in NBS, the most common is flow-injection analysis (FIA-) MS/MS, where the sample is introduced as a bolus injection into the mass spectrometer without the prior fractionation of analytes. Liquid chromatography combined with MS/MS (LC-MS/MS) has been employed for second-tier tests to reduce the false-positive rate associated with several nonspecific screening markers, beginning two decades ago. More recently, LC-MS/MS has been applied to primary screening for new conditions for which FIA-MS/MS or other methods, including genomic screening, are not yet adequate. In addition to providing a list of the currently used LC-MS/MS-based assays for NBS, the authors share their experience regarding the maintenance requirements of LC-MS/MS vs. FIA-MS/MS systems. The consensus is that the maintenance of LC-MS/MS and FIA-MS/MS instrumentation is similar, and LC-MS/MS has the advantage of allowing for a larger number of diseases to be screened for in a multiplex, cost-effective fashion with a high throughput and an adequate turnaround time.

Background: Acid sphingomyelinase deficiency (ASMD) is a lysosomal disorder caused by deficiency of acid sphingomyelinase (ASM) leading to the accumulation of sphingomyelin (SM) in a variety of cell types. Lysosphingomyelin (LysoSM) is the de-acetylated form of SM and it has been shown as a biomarker for ASMD in tissues, plasma, and dried blood spots (DBS) and lysosphingomyelin-509 (LysoSM509) is the carboxylated analogue of LysoSM. High levels of Lysosphingomyelin 509 (LysoSM509) have also been shown in ASMD patients. In this study, we report the utility of the quantification of LysoSM and LysoSM509 in DBS of patients from Latin America with ASMD by ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS)., Results: DBS samples from 14 ASMD patients were compared with 15 controls, and 44 general newborns. All patients had their diagnosis confirmed by the quantification of ASM and the measurement of the activity of chitotriosidase. All patients had significantly higher levels of lysoSM and lysoSM509 compared to controls and general newborns., Conclusions: The quantification of lysosphingolipids in DBS is a valuable tool for the diagnosis of ASMD patients and lysoSM can be useful in the differential diagnosis with NPC. This method is also valuable in the ASMD newborn screening process., (© 2022. The Author(s).)

Background and Objectives: Fragile X syndrome (FXS) is a neurodevelopmental disorder, identified as the most common cause of hereditary intellectual disability and monogenic cause of autism spectrum disorders (ASDs), caused by the loss of fragile X mental retardation protein (FMRP). FMRP is an RNA-binding protein, a regulator of translation that plays an important role in neurodevelopment, and its loss causes cognitive and behavioral deficits. MicroRNAs (miRNAs) are small molecules that regulate gene expression in diverse biological processes. Previous studies found that the interaction of FMRP with miR-125b and miR-132 regulates the maturation and synaptic plasticity in animal models and miRNA dysregulation plays a role in the pathophysiology of FXS. The present study aimed to analyze the expression of miR-125b-5p and miR-132-3p in the serum of patients with FXS., Methods: The expressions of circulating miRNAs were studied in the serum of 10 patients with FXS and 20 controls using the real-time quantitative retrotranscribed method analyzed by relative quantification. Receiver operating characteristic (ROC) curves and the area under the ROC curve (AUC) were generated to assess the diagnostic values of the miRNAs., Results: We found that both miR-125b and miR-132 were increased in the serum of patients with FXS compared with controls and likely involved with FMRP loss. The AUC (95% confidence interval) of miR-125b and miR-132 was 0.94 (0.86-1.0) and 0.89 (0.77-1.0), respectively. Databases allowed for the identification of possible target genes for miR-125b and miR-132, whose products play an important role in the homeostasis of the nervous system., Discussion: Our results indicate that serum miR-125b and miR-132 may serve as potential biomarkers for FXS. The increased expression of circulating miR-125b and miR-132 seems to be associated with the genotype of FXS. Predicted gene targets of the differentially regulated miRNAs are involved in cognitive performance and ASD phenotype., Classification of Evidence: This study provides Class III evidence that miR-125b and miR-132 distinguish men with FXS from normal controls., (Copyright © 2022 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Neurology.)

Introduction: Thromboembolic events occur due to an imbalance in the hemostasis and some factors associated with this condition can be inherited. In order to evaluate the frequency of genotypes considered to be common hereditary risk factors for thrombophilia associated with venous thrombosis (g.1691G > A and g.20210G > A) and hyperhomocysteinemia (g.677C > T and g.1298A > C), samples from voluntary healthy blood donors at the Hospital de Clínicas de Porto Alegre were tested., Methods: We examined 325 blood samples from blood donors collected from October 2017 to July 2018. Blood was collected on filter paper and the DNA was extracted for single nucleotide polymorphisms (SNPs) analysis using the qualitative real time polymerase chain reaction., Results: The calculated frequencies of each genetic variant in heterozygosity were 4% for the FV gene (g.1691G > A), 4% for the F2 gene (g.20210G > A) and 42% and 39% for methylenetetrahydrofolate reductase (MTHFR), g.677C > T and g.1298A > C, respectively. Only the genetic variants of MTHFR were found in homozygosity, with frequencies of 14% and 6% (g.677C > T and g.1298A > C), respectively., Discussion: Altogether, these results describe the frequencies of genetic variants associated with venous thrombosis and hyperhomocysteinemia in the analyzed group and are important to enhance our current knowledge about the genetic profiles of Brazilian blood donors., (Copyright © 2021 Associação Brasileira de Hematologia, Hemoterapia e Terapia Celular. Published by Elsevier España, S.L.U. All rights reserved.)

Niemann-Pick disease type C (NPC) is a lysosomal disorder caused by impaired cholesterol metabolism. Levels of lysosphingomyelin 509 (LysoSM509) have been shown elevated in dried blood spots (DBS) of NPC and acid sphingomyelinase deficiency patients. In this study, we report our experience using a two-tier approach (1st tier is the quantification of lysoSM509 by ultra-performance liquid chromatography tandem mass spectrometry followed by the 2nd tier with next-generation sequencing of the NPC1 and NPC2 genes). DBS samples from 450 suspected patients were received by the NPC Brazil network. Of these, 33 samples had elevated levels of lysoSM509, and in 25 of them, variants classified as pathogenic, likely pathogenic, or of unknown significance were identified in the NPC1 or NPC2 genes by next-generation sequencing. The quantification of lysoSM509 in DBS as a first-tier test for the diagnosis of NPC followed by molecular analysis of the NPC1 and NPC2 genes almost doubled the detection rate when compared to the performance of chitotriosidase activity as a first-tier biomarker, and it could likely be increased with the addition of a third tier with MLPA of the two genes involved. This strategy seems suitable for the neonatal screening (NBS) of NPC if this disease is eventually adopted by NBS programs.

Aromatic l-amino acid decarboxylase (AADC, EC 4.1.1.28) deficiency is a rare genetic disorder characterized by developmental delay, oculogyric crises, autonomic dysfunction and other problems, caused by biallelic mutations in the DDC gene leading to deficient activity of aromatic l-amino acid decarboxylase, an enzyme involved in the formation of important neurotransmitters, such as dopamine and serotonin. A clinical development program of gene therapy for AADC deficiency is ongoing. An important step for the success of this therapy is the early and precise identification of the affected individuals, but it has been estimated that around 90% of the cases remain undiagnosed. The availability measurement of the AADC activity is mandatory for an accurate biochemical diagnosis. Based on these statements, our objectives were to develop a liquid chromatography tandem mass spectrometry (LC-MS/MS) method suitable for the determination of the AADC activity, and to evaluate its capacity to confirm the deficiency of AADC in potential patients in Brazil. The AADC activities were measured in plasma samples of seven AADC deficient patients and 35 healthy controls, after enzymatic reaction and LC-MS/MS analysis of dopamine, the main reaction product. The results obtained showed clear discrimination between confirmed AADC deficient patients and healthy controls. The method presented here could be incorporated in the IEM laboratories for confirmation of the diagnosis of when a suspicion of AADC deficiency is present due to clinical signs and/or abnormal biomarkers, including when an increased level of 3- O -methyldopa (3-OMD) is found in dried blood spots (DBS) samples from high-risk patients or from newborn screening programs., (© 2022 The Authors.)

Background: Mucopolysaccharidosis type I (MPS I) is an inherited disease caused by deficiency of the enzyme alpha-l-iduronidase (IDUA). MPS I affects several tissues, including the brain, leading to cognitive impairment in the severe form of the disease. Currently available treatments do not reach the brain. Therefore, in this study, we performed nasal administration (NA) of liposomal complexes carrying two plasmids encoding for the CRISPR/Cas9 system and for the IDUA gene targeting the ROSA26 locus, aiming at brain delivery in MPS I mice., Methods: Liposomes were prepared by microfluidization, and the plasmids were complexed to the formulations by adsorption. Physicochemical characterization of the formulations and complexes, in vitro permeation, and mucoadhesion in porcine nasal mucosa (PNM) were assessed. We performed NA repeatedly for 30 days in young MPS I mice, which were euthanized at 6 months of age after performing behavioral tasks, and biochemical and molecular aspects were evaluated., Results: Monodisperse mucoadhesive complexes around 110 nm, which are able to efficiently permeate the PNM. In animals, the treatment led to a modest increase in IDUA activity in the lung, heart, and brain areas, with reduction of glycosaminoglycan (GAG) levels in serum, urine, tissues, and brain cortex. Furthermore, treated mice showed improvement in behavioral tests, suggesting prevention of the cognitive damage., Conclusion: Nonviral gene editing performed through nasal route represents a potential therapeutic alternative for the somatic and neurologic symptoms of MPS I and possibly for other neurological disorders., (© 2022 John Wiley & Sons, Ltd.)

Mucopolysaccharidosis type IIIB is a rare autosomal recessive disorder characterized by deficiency of the enzyme N-acetyl-alpha-d-glucosaminidase (NAGLU), caused by biallelic pathogenic variants in the NAGLU gene, which leads to storage of heparan sulfate and a series of clinical consequences which hallmark is neurodegeneration. In this study clinical, epidemiological, and biochemical data were obtained from MPS IIIB patients diagnosed from 2004-2019 by the MPS Brazil Network ("Rede MPS Brasil"), which was created with the goal to provide an easily accessible and comprehensive investigation of all MPS types. One hundred and ten MPS IIIB patients were diagnosed during this period. Mean age at diagnosis was 10.9 years. Patients were from all over Brazil, with a few from abroad, with a possible cluster of MPS IIIB identified in Ecuador. All patients had increased urinary levels of glycosaminoglycans and low NAGLU activity in blood. Main clinical symptoms reported at diagnosis were coarse facies and neurocognitive regression. The most common variant was p.Leu496Pro (30% of alleles). MPS IIIB seems to be relatively frequent in Brazil, but patients are diagnosed later than in other countries, and reasons for that probably include the limited awareness about the disease by health professionals and the difficulties to access diagnostic tests, factors that the MPS Brazil Network is trying to mitigate., (© 2021 Wiley Periodicals LLC.)

Metachromatic leukodystrophy (MLD) is an autosomal recessive lysosomal disorder caused by deficiency of arylsulfatase A (ARSA), leading to an accumulation of sulfatides. Sulfatides have been quantified in urine, dried blood spots (DBS), and tissues of patients with MLD. Newborn screening (NBS) for MLD has already been proposed based on a two-tier approach with the quantification of sulfatides in DBS followed by the quantification of ARSA by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Prenatal screening for MLD is also crucial, and sulfatide quantification in amniotic fluid (AF) can aid diagnosis. The prenatal study was initiated due to a family history of MLD at 19 weeks of gestation. ARSA was quantified in cultured amniocytes. C16:0 sulfatide was quantified by LC-MS/MS in the supernatant of AF. Molecular analysis of the ARSA gene was performed in cultured amniocytes. ARSA was deficient in fetal cells, and C16:0 sulfatides were significantly elevated in comparison to age-matched controls (3-fold higher). Genetic studies identified the c.465+1G>A variant in homozygosis in the ARSA gene. Our study shows that sulfatides can be quantified in the supernatant of AF of MLD fetuses, and it could potentially aid in a faster and more accurate diagnosis of MLD patients., Competing Interests: Francyne Kubaski, Maira Graeff Burin, Kristiane Michelin‐Tirelli, Franciele B. Trapp, Rejane Gus, Alice B. O. Netto, Ana Carolina Brusius‐Facchin, Sandra Leistner‐Segal, Maria Teresa Sanseverino, Carolina Moura Fischinger de Souza, Matheus V. M. B. Wilke, Thiago Oliveira, Jose A. A. Magalhães, Roberto Giugliani declare that they have no conflict of interest. Zackary M. Herbst is a consultant for GelbChem, LLC., (© 2022 The Authors. JIMD Reports published by John Wiley & Sons Ltd on behalf of SSIEM.)

Background and Aims: Niemann-Pick disease (NPD) types A (NPA) and B (NPB) are caused by deficiency of the acid sphingomyelinase enzyme, which is encoded by the SMPD1 gene, resulting in progressive pathogenic accumulation of lipids in tissues. Trehalose has been suggested as an autophagy inducer with therapeutic neuroprotective effects. We performed a single-arm, open-label pilot study to assess the potential efficacy of trehalose treatment in patients with NPA and NPB patients., Methods: Five patients with NPD type A and B were enrolled in an open-label, single-arm clinical trial. Trehalose was administrated intravenously (IV) (15 g/week) for three months. The efficacy of trehalose in the management of clinical symptoms was evaluated in patients by assessing the quality of life, serum biomarkers, and high-resolution computed tomography (HRCT) of the lungs at the baseline and end of the interventional trial (day 0 and week 12)., Results: The mean of TNO-AZL Preschool children Quality of Life (TAPQOL) scores increased in all patients after intervention at W12 compared to the baseline W0, although the difference was not statistically significant. The serum levels of lyso-SM-509 and lyso-SM were decreased in three and four patients out of five, respectively, compared with baseline. Elevated ALT and AST levels were decreased in all patients after 12 weeks of treatment; however, changes were not statistically significant. Pro-oxidant antioxidant balance (PAB) was also decreased and glutathione peroxidase (GPX) activity was increased in serum of patients at the end of the study. Imaging studies of spleen and lung HRCT showed improvement of symptoms in two patients., Conclusions: Positive trends in health-related quality of life (HRQoL), serum biomarkers, and organomegaly were observed after 3 months of treatment with trehalose in patients with NPA and NPB. Although not statistically significant, due to the small number of patients enrolled, these results are encouraging and should be further explored.

The COVID-19 pandemic led to the reorganization of health care in several countries, including Brazil. Inborn Errors of Metabolism (IEM) are a group of rare and difficult to diagnose genetic diseases caused by pathogenic variants in genes that code for enzymes, cofactors, or structural proteins affecting different metabolic pathways. The aim of this study was to evaluate how COVID-19 affected the diagnosis of patients with IEM during the first year of the pandemic in Brazil comparing two distinct periods: from March 1st, 2019 to February 29th, 2020 (TIME A) and from March 1st, 2020 to February 28th, 2021 (TIME B), by the analysis of the number of tests and diagnoses performed in a Reference Center in South of Brazil. In the comparison TIME A with TIME B, we observe a reduction in the total number of tests performed (46%) and in the number of diagnoses (34%). In both periods analyzed, mucopolysaccharidoses (all subtypes combined) was the most frequent LD suspected and/or confirmed. Our data indicates a large reduction in the number of tests requested for the investigation of IEM and consequently a large reduction in the number of diagnoses caused by the COVID-19 pandemic leading to a significant underdiagnosis of IEM.