Disease progression in Sanfilippo type B: Case series of Brazilian patients.

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.

Consecutive Liver and Bone Marrow Transplantation for Erythropoietic Protoporphyria: Case Report and Literature Review.

BACKGROUND: Erythropoietic protoporphyria (EPP) is a rare inherited disease of heme biosynthesis resulting in the accumulation of protoporphyrin, characterized by liver failure in a minority of cases. Although liver transplant (LT) is the therapeutic strategy for advanced hepatic disease, it does not correct the primary defect, which leads to recurrence in liver graft. Thus, hematopoietic stem cell transplantation (HSCT) is an approach for treating EPP. METHODS: We aim to describe the first sequential LT and HSCT for EPP performed in Latin America, besides reviewing the present-day literature. RESULTS: The patient, a 13-year-old female with a history of photosensitivity, presented with symptoms of cholestatic and hepatopulmonary syndrome and was diagnosed with EPP. Liver biopsy demonstrated cirrhosis. She was submitted to a successful LT and showed improvement of respiratory symptoms. However, she had disease recurrence on the liver graft. She underwent a myeloablative HSCT using a matched unrelated donor, conditioning with BuCy (busulfan and cyclophosphamide), and GvHD (graft vs. host disease) prophylaxis with ATG (thymoglobulin), tacrolimus and methotrexate. Neutrophil engraftment occurred on D+18. She has presented mixed chimerism, but normalization of PP levels, being 300 days after HSCT, in good state of health and normal liver function. CONCLUSIONS: Consecutive LT and HSCT for EPP is a procedure that has been described in 10 cases in the literature and, even though these patients are a highly diversified population, studies have shown favorable results. This concept of treatment should be considered in patients with established liver disease.

Efficacy and safety of empagliflozin in glycogen storage disease type Ib: Data from an international questionnaire.

PURPOSE: This paper aims to report collective information on safety and efficacy of empagliflozin drug repurposing in individuals with glycogen storage disease type Ib (GSD Ib). METHODS: This is an international retrospective questionnaire study on the safety and efficacy of empagliflozin use for management of neutropenia/neutrophil dysfunction in patients with GSD Ib, conducted among the respective health care providers from 24 countries across the globe. RESULTS: Clinical data from 112 individuals with GSD Ib were evaluated, representing a total of 94 treatment years. The median age at start of empagliflozin treatment was 10.5 years (range = 0-38 years). Empagliflozin showed positive effects on all neutrophil dysfunction-related symptoms, including oral and urogenital mucosal lesions, recurrent infections, skin abscesses, inflammatory bowel disease, and anemia. Before initiating empagliflozin, most patients with GSD Ib were on G-CSF (94/112; 84%). At the time of the survey, 49 of 89 (55%) patients previously treated with G-CSF had completely stopped G-CSF, and another 15 (17%) were able to reduce the dose. The most common adverse event during empagliflozin treatment was hypoglycemia, occurring in 18% of individuals. CONCLUSION: Empagliflozin has a favorable effect on neutropenia/neutrophil dysfunction-related symptoms and safety profile in individuals with GSD Ib.

Sanfilippo syndrome type B: Analysis of patients diagnosed by the MPS Brazil Network.

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.

SARS-CoV-2 pandemic in the Brazilian community of rare diseases: A patient reported survey.

The COVID-19 pandemic has led to a reorganization of health systems to prioritize the fight against the virus. The adoption of social distancing interfered with the flow of existing policies, and may thus negatively affect the most vulnerable groups, such as the rare disease community. Aimming at characterizing the perception of the impact of COVID-19 on the health care of the Brazilian rare disease community, an online questionnaire addressed to patients with rare diseases and their caregivers was disseminated in the Brazilian territory between June 1st to July 5th, 2020. The questions dealt with the sanitary measures adopted; access to medical services; and mental suffering during the pandemic. The survey was answered by 1,466 participants (<18 yo = 53.3%) representing 192 rare diseases. Regarding physical distancing, 1,372 (93.6%) participants did not leave their residence, or did so only when essential; 1,321 (90.1%) always wore masks when leaving home. 1,042 (71.1%) and 995 (67.9%) participants, respectively, referred medical genetics appointments and rehabilitation therapies were postponed/canceled. Telemedicine was experienced by 1,026 (70%), and 68.3% agreed this is a good strategy for health care. Patients with Inborn Errors of Metabolism (IEM, n = 624, 42.5%) appear to have more access to information and ability to overcome difficulties, and feel less threatened, lonely and depressed than the non-IEM group (p < .05). There was an increment of the rare disease patients' vulnerability in the pandemic scenario. The cooperation of patients/caregivers along with adaptation of the health system is crucial and may be so even post-pandemic.

Genotype-phenotype studies in a large cohort of Brazilian patients with Hunter syndrome.

Mucopolysaccharidosis type II (MPS II) is an X-linked inherited disease caused by pathogenic variants in the IDS gene, leading to deficiency of the lysosomal enzyme iduronate-2-sulfatase and consequent widespread storage of glycosaminoglycans, leading to several clinical consequences, with progressive manifestations which most times includes cognitive decline. MPS II has wide allelic and clinical heterogeneity and a complex genotype-phenotype correlation. We evaluated data from 501 Brazilian patients diagnosed with MPS II from 1982 to 2020. We genotyped 280 of these patients (55.9%), which were assigned to 206 different families. Point mutations were present in 70% of our patients, being missense variants the most frequent. We correlated the IDS pathogenic variants identified with the phenotype (neuronophatic or non-neuronopathic). Except for two half-brothers, there was no discordance in the genotype-phenotype correlation among family members, nor among MPS II patients from different families with the same single base-pair substitution variant. Mothers were carriers in 82.0% of the cases. This comprehensive study of the molecular profile of the MPS II cases in Brazil sheds light on the genotype-phenotype correlation and helps the better understanding of the disease and the prediction of its clinical course, enabling the provision of a more refined genetic counseling to the affected families.

The fructose-1,6-bisphosphatase deficiency and the p.(Lys204ArgfsTer72) variant.

Fructose-1,6-bisphosphatase (FBPase) deficiency is a rare inborn error of fructose metabolism caused by pathogenic variants in the FBP1 gene. As gluconeogenesis is affected, catabolic episodes can induce ketotic hypoglycemia in patients. FBP1 analysis is the most commonly used approach for the diagnosis of this disorder. Herein, a Brazilian patient is reported. The proband, a girl born to a consanguineous couple, presented with severe hypoglycemia crisis in the neonatal period. At the age 17 months, presented a new crisis accompanied by metabolic acidosis associated with a feverish episode. Genetic analysis was performed by next-generation sequencing (NGS), identifying the NM_000507.3:c.611_614del variant in homozygosis in the FBP1 gene. In silico analysis and 3D modeling were performed, suggesting that this variant is associated with a loss of sites for substrate and Mg2+ binding and for posttranslational modifications of FBPase. The c.611_614del variant is located in a repetitive region of the FBP1 gene that appears to be a hotspot for mutational events. This frameshift creates a premature termination codon in the last coding exon which escapes the nonsense-mediated decay mechanism, according to in silico analysis. This variant results in an intrinsically disordered protein with loss of substrate recognition and post-translational modification sites.

Lessons learned from 40 novel PIGA patients and a review of the literature.

OBJECTIVE: To define the phenotypic spectrum of phosphatidylinositol glycan class A protein (PIGA)-related congenital disorder of glycosylation (PIGA-CDG) and evaluate genotype-phenotype correlations. METHODS: Our cohort encompasses 40 affected males with a pathogenic PIGA variant. We performed a detailed phenotypic assessment, and in addition, we reviewed the available clinical data of 36 previously published cases and assessed the variant pathogenicity using bioinformatical approaches. RESULTS: Most individuals had hypotonia, moderate to profound global developmental delay, and intractable seizures. We found that PIGA-CDG spans from a pure neurological phenotype at the mild end to a Fryns syndrome-like phenotype. We found a high frequency of cardiac anomalies including structural anomalies and cardiomyopathy, and a high frequency of spontaneous death, especially in childhood. Comparative bioinformatical analysis of common variants, found in the healthy population, and pathogenic variants, identified in affected individuals, revealed a profound physiochemical dissimilarity of the substituted amino acids in variant constrained regions of the protein. SIGNIFICANCE: Our comprehensive analysis of the largest cohort of published and novel PIGA patients broadens the spectrum of PIGA-CDG. Our genotype-phenotype correlation facilitates the estimation on pathogenicity of variants with unknown clinical significance and prognosis for individuals with pathogenic variants in PIGA.

GNB5 Mutations Cause an Autosomal-Recessive Multisystem Syndrome with Sinus Bradycardia and Cognitive Disability.

GNB5 encodes the G protein ß subunit 5 and is involved in inhibitory G protein signaling. Here, we report mutations in GNB5 that are associated with heart-rate disturbance, eye disease, intellectual disability, gastric problems, hypotonia, and seizures in nine individuals from six families. We observed an association between the nature of the variants and clinical severity; individuals with loss-of-function alleles had more severe symptoms, including substantial developmental delay, speech defects, severe hypotonia, pathological gastro-esophageal reflux, retinal disease, and sinus-node dysfunction, whereas related heterozygotes harboring missense variants presented with a clinically milder phenotype. Zebrafish gnb5 knockouts recapitulated the phenotypic spectrum of affected individuals, including cardiac, neurological, and ophthalmological abnormalities, supporting a direct role of GNB5 in the control of heart rate, hypotonia, and vision.

Aortic root dilatation in patients with mucopolysaccharidoses and the impact of enzyme replacement therapy.

Mucopolysaccharidoses (MPS) are disorders characterized by impaired glycosaminoglycan (GAG) catabolism as a consequence of a deficiency or the absence of lysosomal enzymes directly involved in their degradation. Multiple organ systems are involved in MPS, including the cardiovascular system. Recently, aortic root dilatation (ARD) has been described in these patients. Thus, we reviewed aortic root diameter measurements in 69 MPS patients from a single center from 2000 to 2016. Aortic root diameter z scores were calculated based on data published by Colan et al. according to the body surface area (BSA) determined using the Haycock formula. The overall incidence of ARD in MPS patients was 39.1%. Higher mean z scores were present in patients with MPS IVA and VI when compared to MPS I and II. Aortic root z scores were higher in older MPS IVA patients, which may suggest a progressive ARD change in this MPS type. No significant differences were found before and after enzyme replacement therapy (ERT) in 11 patients with available data (2 with MPS I; 4 with MPS II; 2 with MPS IVA, and 3 with MPS VI). This work provides further evidence that ARD is common in different types of MPS, being especially evident in MPS IVA, but with a significant occurrence also in MPS VI.

Lysosomal diseases: Overview on current diagnosis and treatment.

Lysosomal diseases (LDs), also known as lysosomal storage diseases (LSDs), are a heterogeneous group of conditions caused by defects in lysosomal function. LDs may result from deficiency of lysosomal hydrolases, membrane-associated transporters or other non-enzymatic proteins. Interest in the LD field is growing each year, as more conditions are, or will soon be treatable. In this article, we review the diagnosis of LDs, from clinical suspicion and screening tests to the identification of enzyme or protein deficiencies and molecular genetic diagnosis. We also cover the treatment approaches that are currently available or in development, including hematopoietic stem cell transplantation, enzyme replacement therapy, small molecules, and gene therapy.

Information and Diagnosis Networks - tools to improve diagnosis and treatment for patients with rare genetic diseases.

Brazil is a country of continental dimensions and most genetic services are concentrated in the Southeast and South, including the Medical Genetics Service of the Hospital de Clínicas de Porto Alegre (MGS/HCPA). As many areas on the country do not have adequate medical genetics support, networks were designed to extend the service of the MGS/HCPA reference center. This paper presents the information and diagnosis networks that have their headquarters at MGS/HCPA: SIAT (National Information System on Teratogenic Agents), SIEM (Information Service on Inborn Errors of Metabolism), Alô Genética (Hello Genetics - Medical Genetics Information Service for Primary Health Care Professionals); Rede MPS Brasil (MPS-Mucopolysaccharidosis Brazil Network); Rede EIM Brasil (IEM-Inborn Errors of Metabolism Brazil Network), Rede NPC Brasil (Niemann-Pick C - NPC Brazil Network), Rede DLD Brasil (LSD-Lysosomal Storage Disorders Brazil Network), Rede DXB (MSUD-Maple Syrup Urine Disease Network), RedeBRIM (Brazilian Network of Reference and Information in Microdeletion Syndromes Project), Rede Neurogenética (Neurogenetics Network), and Rede Brasileira de Câncer Hereditário (Brazilian Hereditary Cancer Network). These tools are very useful to provide access to a qualified information and/or diagnostic service for specialized and non-specialized health services, bypassing difficulties that preclude patients to access reference centers.

ALG6-CDG: a recognizable phenotype with epilepsy, proximal muscle weakness, ataxia and behavioral and limb anomalies.

INTRODUCTION: Alpha-1,3-glucosyltransferase congenital disorder of glycosylation (ALG6-CDG) is a congenital disorder of glycosylation. The original patients were described with hypotonia, developmental disability, epilepsy, and increased bleeding tendency. METHODS: Based on Euroglycan database registration, we approached referring clinicians and collected comprehensive data on 41 patients. RESULTS: We found hypotonia and developmental delay in all ALG6-CDG patients and epilepsy, ataxia, proximal muscle weakness, and, in the majority of cases, failure to thrive. Nine patients developed intractable seizures. Coagulation anomalies were present in <50 % of cases, without spontaneous bleedings. Facial dysmorphism was rare, but seven patients showed missing phalanges and brachydactyly. Cyclic behavioral change, with autistic features and depressive episodes, was one of the most significant complaints. Eleven children died before the age of 4 years due to protein losing enteropathy (PLE), sepsis, or seizures. The oldest patient was a 40 year-old Dutch woman. The most common pathogenic protein alterations were p.A333V and p.I299Del, without any clear genotype-phenotype correlation. DISCUSSION: ALG6-CDG has been now described in 89 patients, making it the second most common type of CDG. It has a recognizable phenotype and a primary neurologic presentation.

Neuroimaging Findings in Patients with Mucopolysaccharidosis: What You Really Need to Know.

Mucopolysaccharidosis (MPS) is an inherited metabolic disease and a member of the group of lysosomal storage disorders. Its hallmark is a deficiency of lysosomal enzymes involved in the degradation of mucopolysaccharides, also known as glycosaminoglycans (GAGs). The products of GAG degradation accumulate within lysosomes and in the extracellular space, thereby interfering with the degradation of other macromolecules. This process leads to chronic degeneration of cells, which in turn affects multiple organs and systems. There are seven distinct types of MPS (I, II, III, IV, VI, VII, and IX), which are divided into subtypes according to the deficient enzyme and the severity of the clinical picture. Although clinical manifestations vary considerably among the different types of MPS, the central nervous system (CNS) is characteristically affected, and magnetic resonance (MR) imaging is the method of choice to evaluate brain and spinal cord abnormalities. Enlarged perivascular spaces, white matter lesions, hydrocephalus, brain atrophy, cervical spinal canal stenosis with or without spinal cord compression and myelopathy, and bone abnormalities in the skull and spine (dysostosis multiplex) are typical imaging findings described in the literature and reviewed in this article. The differential diagnosis of MPS is limited because the constellation of imaging findings is highly suggestive. Thus, radiologists should be aware of its typical neuroimaging findings so they can recognize cases not yet diagnosed, exclude other metabolic diseases, monitor CNS findings over time, and assess treatment response. (©)RSNA, 2016.

c.G2114A MYH9 mutation (DFNA17) causes non-syndromic autosomal dominant hearing loss in a Brazilian family.

We studied a family presenting 10 individuals affected by autosomal dominant deafness in all frequencies and three individuals affected by high frequency hearing loss. Genomic scanning using the 50k Affymetrix microarray technology yielded a Lod Score of 2.1 in chromosome 14 and a Lod Score of 1.9 in chromosome 22. Mapping refinement using microsatellites placed the chromosome 14 candidate region between markers D14S288 and D14S276 (8.85 cM) and the chromosome 22 near marker D22S283. Exome sequencing identified two candidate variants to explain hearing loss in chromosome 14 [PTGDR - c.G894A:p.R298R and PTGER2 - c.T247G:p.C83G], and one in chromosome 22 [MYH9, c.G2114A:p.R705H]. Pedigree segregation analysis allowed exclusion of the PTGDR and PTGER2 variants as the cause of deafness. However, the MYH9 variant segregated with the phenotype in all affected members, except the three individuals with different phenotype. This gene has been previously described as mutated in autosomal dominant hereditary hearing loss and corresponds to DFNA17. The mutation identified in our study is the same described in the prior report. Thus, although linkage studies suggested a candidate gene in chromosome 14, we concluded that the mutation in chromosome 22 better explains the hearing loss phenotype in the Brazilian family.

Clinical Characterization and Underlying Genetic Findings in Brazilian Patients with Syndromic Microcephaly Associated with Neurodevelopmental Disorders.

Microcephaly is characterized by an occipitofrontal circumference at least two standard deviations below the mean for age and sex. Neurodevelopmental disorders (NDD) are commonly associated with microcephaly, due to perturbations in brain development and functioning. Given the extensive genetic heterogeneity of microcephaly, managing patients is hindered by the broad spectrum of diagnostic possibilities that exist before conducting molecular testing. We investigated the genetic basis of syndromic microcephaly accompanied by NDD in a Brazilian cohort of 45 individuals and characterized associated clinical features, as well as evaluated the effectiveness of whole-exome sequencing (WES) as a diagnostic tool for this condition. Patients previously negative for pathogenic copy number variants underwent WES, which was performed using a trio approach for isolated index cases (n = 31), only the index in isolated cases with parental consanguinity (n = 8) or affected siblings in familial cases (n = 3). Pathogenic/likely pathogenic variants were identified in 19 families (18 genes) with a diagnostic yield of approximately 45%. Nearly 86% of the individuals had global developmental delay/intellectual disability and 51% presented with behavioral disturbances. Additional frequent clinical features included facial dysmorphisms (80%), brain malformations (67%), musculoskeletal (71%) or cardiovascular (47%) defects, and short stature (54%). Our findings unraveled the underlying genetic basis of microcephaly in half of the patients, demonstrating a high diagnostic yield of WES for microcephaly and reinforcing its genetic heterogeneity. We expanded the phenotypic spectrum associated with the condition and identified a potentially novel gene (CCDC17) for congenital microcephaly.

Cannabidiol Add-On in Glycosylphosphatidylinositol-Related Drug-Resistant Epilepsy.

Background: Glycosylphosphatidylinositol-anchored protein deficiencies (GPI-ADs) are commonly associated with drug-resistant epilepsy (DRE). Cannabidiol (CBD) is approved for the adjunctive treatment of seizures in Dravet/Lennox-Gastaut Syndromes and Tuberous Sclerosis Complex. We report on the efficacy and safety of CBD for the treatment of DRE in patients with genetically proven GPI-AD. Patients and Methods: Patients received add-on treatment with purified GW-pharma CBD (Epidyolex®). Efficacy endpoints were the percentage of patients with ≥50% (responders) or >25<50% (partial responders) reduction in monthly seizures from baseline and at 12 (M12) months of follow-up. Safety was evaluated through adverse events (AEs) monitoring. Results: Six patients (5 males) were enrolled. The median age at seizures onset was 5 months and the syndromic diagnosis was early infantile developmental and epileptic encephalopathy in 4 patients and focal non-lesional epilepsy or GEFS+ in one patient each. Five out of six (83%) patients were responders at M12, while one was a partial responder. No severe AEs were reported. Mean prescribed CBD dose was 17.85 mg/kg/day and median treatment duration is currently 27 months. Conclusions: In summary, off-label treatment with CBD was effective and safe in patients with DRE due to GPI-ADs.

Leigh syndrome global patient registry: uniting patients and researchers worldwide.

BACKGROUND: Leigh Syndrome (LS) is a rare genetic neurometabolic disorder, that leads to the degeneration of the central nervous system and subsequently, early death. LS can be caused by over 80 mutations in mitochondrial or nuclear DNA. Patient registries are important for many reasons, such as studying the natural history of the disease, improving the quality of care, and understanding the healthcare burden. For rare diseases, patient registries are significantly important as patient numbers are small, and funding is limited. Cure Mito Foundation started a global patient registry for LS in September 2021 to identify and learn about the LS patient population, facilitate clinical trial recruitment, and unite international patients and researchers. Priorities were to allow researchers and industry partners to access data at no cost through a clear and transparent process, active patient engagement, and sharing of results back to the community. RESULTS: Patient registry platform, survey design, data analysis process, and patient recruitment strategies are described. Reported results include demographics, diagnostic information, symptom history, loss of milestones, disease management, healthcare utilization, quality of life, and caregiver burden for 116 participants. Results show a high disease burden, but a relatively short time to diagnosis. Despite the challenges faced by families impacted by Leigh syndrome, participants, in general, are described as having a good quality of life and caregivers are overall resilient, while also reporting a significant amount of stress. CONCLUSION: This registry provides a straightforward, no-cost mechanism for data sharing and contacting patients for clinical trials or research participation, which is important given the recruitment challenges for clinical trials for rare diseases. This is the first publication to present results from a global patient registry for Leigh Syndrome, with details on a variety of patient-specific and caregiver outcomes reported for the first time. Additionally, this registry is the first for any mitochondrial disease with nearly 70% of participants residing outside of the United States. Future efforts include continued publication of results and further collaboration with patients, industry partners, and researchers.

Oral Dantrolene Reduces Myalgia and Hyperckemia in a Child with RYR1-Related Exertional Myalgia/Rhabdomyolysis.

RYR1-related exertional myalgia/rhabdomyolysis (ERM) is an underrecognized condition, which can cause limiting muscle symptoms, and may account for more than one-third of undiagnosed rhabdomyolysis cases. Dantrolene has shown promising results in controlling muscle symptoms in individuals with ERM, however, its use in children remains poorly documented. This case report presents the successful treatment of a 5-year-old patient with ERM using oral dantrolene. The patient experienced notable improvements, including a reduction in the frequency and intensity of myalgia episodes, no hospitalizations due to rhabdomyolysis, a substantial decrease in creatine phosphokinase (CPK) levels, and enhanced performance on the 6-minute walk test. The use of dantrolene was well-tolerated, and no significant adverse effects were observed. This report adds to the existing evidence supporting the effectiveness of oral dantrolene in managing ERM, and, to the best of our knowledge, this is the first report of the use of dantrolene in a pediatric patient for controlling anesthesia-independent muscle symptoms.