-
Journal of Cellular and Molecular... Apr 2024Mucopolysaccharidosis type IIIC (MPS IIIC) is one of inherited lysosomal storage disorders, caused by deficiencies in lysosomal hydrolases degrading acidic...
Mucopolysaccharidosis type IIIC (MPS IIIC) is one of inherited lysosomal storage disorders, caused by deficiencies in lysosomal hydrolases degrading acidic mucopolysaccharides. The gene responsible for MPS IIIC is HGSNAT, which encodes an enzyme that catalyses the acetylation of the terminal glucosamine residues of heparan sulfate. So far, few studies have focused on the genetic landscape of MPS IIIC in China, where IIIA and IIIB were the major subtypes. In this study, we utilized whole-exome sequencing (WES) to identify novel compound heterozygous variants in the HGSNAT gene from a Chinese patient with typical MPS IIIC symptoms: c.743G>A; p.Gly248Glu and c.1030C>T; p.Arg344Cys. We performed in silico analysis and experimental validation, which confirmed the deleterious pathogenic nature of both variants, as evidenced by the loss of HGSNAT activity and failure of lysosomal localization. To the best of our knowledge, the MPS IIIC is first confirmed by clinical, biochemical and molecular genetic findings in China. Our study thus expands the spectrum of MPS IIIC pathogenic variants, which is of importance to dissect the pathogenesis and to carry out clinical diagnosis of MPS IIIC. Moreover, this study helps to depict the natural history of Chinese MPS IIIC populations.
Topics: Humans; Acetylation; Acetyltransferases; Asian People; China; Mucopolysaccharidoses; Mucopolysaccharidosis III
PubMed: 38613342
DOI: 10.1111/jcmm.18307 -
Orphanet Journal of Rare Diseases Apr 2024Mucopolysaccharidosis II (MPS II) is a rare lysosomal storage disease characterized by iduronate-2-sulfatase gene (IDS) deficiency and downstream glycosaminoglycan...
BACKGROUND
Mucopolysaccharidosis II (MPS II) is a rare lysosomal storage disease characterized by iduronate-2-sulfatase gene (IDS) deficiency and downstream glycosaminoglycan accumulation. Two-thirds of patients present with neuronopathic disease and evaluating cognitive function in these patients is challenging owing to limitations of currently available tests. During the clinical development of intrathecal idursulfase (idursulfase-IT), regulatory authorities requested qualitative data to further understand the neurocognitive changes observed by the investigators through the clinical trials.
RESULTS
This qualitative study consisted of semi-structured interviews with all nine of the principal investigators who participated in the idursulfase-IT phase 2/3 (NCT02055118) and extension (NCT02412787) trials. These investigators enrolled the 56 patients with neuronopathic MPS II who qualified for the extension phase of the trial. The investigators were asked to rate the disease status of their patients. Of the 56 patients, 49 (88%) were rated as having disease that was improved/improving, stabilized or slowing progression compared with the expected outcomes with no treatment. Three patients were rated as worsening, while the remaining four patients were considered to have slowing progression or worsening disease. Similar results were demonstrated for patients aged from 3 to under 6 years at baseline, with 33 of 39 patients (85%) rated as having disease that was improved/improving, stabilized or slowing progression. Of the seven patients rated with slowing progression/worsening or worsening disease, five of them had an IDS variant other than missense, while two had a missense class variant. All the assigned improved/improving ratings were in patients receiving idursulfase-IT from the start of the phase 2/3 trial. Moreover, patients under 3 years of age at baseline were all rated as either improved/improving or stabilized disease. In a blinded review of patient profiles, investigators were requested to assign a disease status rating to 18 patients with large IDS deletions; 67% of these patients were rated as improved/improving or stabilized disease.
CONCLUSIONS
This qualitative analysis provides a snapshot of clinicians' considerations when evaluating treatment in patients with neuronopathic MPS II, compared with the expected decline in cognitive function in the absence of treatment. The results highlight the importance of robust assessment tools in treatment evaluation.
Topics: Child; Humans; Mucopolysaccharidosis II; Research Personnel; Iduronate Sulfatase; Lysosomal Storage Diseases
PubMed: 38610004
DOI: 10.1186/s13023-024-03147-4 -
The American Journal of Case Reports Apr 2024BACKGROUND Bow hunter syndrome is a rare disease that is often overlooked. It presents with complex and variable clinical symptoms and causes, making diagnosis and...
BACKGROUND Bow hunter syndrome is a rare disease that is often overlooked. It presents with complex and variable clinical symptoms and causes, making diagnosis and treatment challenging. This case report focuses on a young patient with bilateral bow hunter syndrome, possibly caused by the loss of cervical physiological curvature. The aim is to enhance understanding and awareness of the disease. It is important to consider the possibility of bow hunter syndrome in young patients with long-term poor neck posture and symptoms such as dizziness, nausea, vomiting, and neck rotation-related symptoms. In such cases, thorough examination of posterior circulation hemodynamics and vascular morphology is recommended. CASE REPORT A 25-year-old woman was admitted to the hospital mainly because of "dizziness for 10 hours." The dizziness was aggravated when the right side of the neck was turned and the body position changed. This was accompanied by visual rotation, nausea, and vomiting. Bow hunter syndrome was diagnosed based on the clinical symptoms and hemodynamic examination of the posterior circulation. The patient was given a cervical collar to limit excessive twisting of the neck and instructed to avoid large-angle deflection of the neck after discharge. During the 3-month follow-up, no characteristic symptoms (such as dizziness) reappeared. CONCLUSIONS Bow hunter syndrome is a rare clinical posterior circulation compression syndrome with complex etiology. This case suggests that the simple disappearance of cervical curvature may be related to the occurrence of bow hunter syndrome. The dynamic monitoring of blood flow by color Doppler ultrasound and transcranial Doppler in different head positions provides clear clues to suspected bow hunter syndrome. With the help of computed tomography angiography, the diagnosis of bow hunter syndrome may be obtained by noninvasive examination.
Topics: Adult; Female; Humans; Cerebral Angiography; Dizziness; Mucopolysaccharidosis II; Nausea; Syndrome; Vertebral Artery; Vertebrobasilar Insufficiency; Vomiting
PubMed: 38605499
DOI: 10.12659/AJCR.942609 -
Clinical Chemistry Jun 2024Mucopolysaccharidosis (MPS) and glycoproteinosis are 2 groups of heterogenous lysosomal storage disorders (LSDs) caused by defective degradation of glycosaminoglycans...
Ultra-Performance Liquid Chromatography-Tandem Mass Spectrometry Analysis of Urinary Oligosaccharides and Glycoamino Acids for the Diagnosis of Mucopolysaccharidosis and Glycoproteinosis.
BACKGROUND
Mucopolysaccharidosis (MPS) and glycoproteinosis are 2 groups of heterogenous lysosomal storage disorders (LSDs) caused by defective degradation of glycosaminoglycans (GAGs) and glycoproteins, respectively. Oligosaccharides and glycoamino acids have been recognized as biomarkers for MPS and glycoproteinosis. Given that both groups of LSDs have overlapping clinical features, a multiplexed assay capable of unambiguous subtyping is desired for accurate diagnosis, and potentially for severity stratification and treatment monitoring.
METHODS
Urinary oligosaccharides were derivatized with 3-methyl-1-phenyl-2-pyrazoline-5-one (PMP) and analyzed by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) together with the underivatized glycoamino acids. Novel biomarkers were identified with a semi-targeted approach with precursor mass scanning, the fragmentation pattern (if applicable), and the biochemical basis of the condition.
RESULTS
A UPLC-MS/MS analysis with improved chromatographic separation was developed. Novel biomarkers for MPS-IIIA, IIIB, IIIC, and VII were identified and validated. A total of 28 oligosaccharides, 2 glycoamino acids, and 2 ratios were selected as key diagnostic biomarkers. Validation studies including linearity, lower limit of quantitation (LLOQ), and precision were carried out with the assay performance meeting the required criteria. Age-specific reference ranges were collected. In the 76 untreated patients, unambiguous diagnosis was achieved with 100% sensitivity and specificity. Additionally, the levels of disease-specific biomarkers were substantially reduced in the treated patients.
CONCLUSIONS
A multiplexed UPLC-MS/MS assay for urinary oligosaccharides and glycoamino acids measurement was developed and validated. The assay is suitable for the accurate diagnosis and subtyping of MPS and glycoproteinosis, and potentially for severity stratification and monitoring response to treatment.
Topics: Humans; Tandem Mass Spectrometry; Oligosaccharides; Child; Chromatography, High Pressure Liquid; Child, Preschool; Biomarkers; Mucopolysaccharidoses; Adolescent; Glycoproteins; Infant; Male; Female; Adult; Amino Acids; Young Adult
PubMed: 38597162
DOI: 10.1093/clinchem/hvae043 -
Journal of Clinical Medicine Feb 2024Mucopolysaccharidoses (MPSs) are rare congenital lysosomal storage disorders due to a deficiency of enzymes metabolising glycosaminoglycans, leading to their...
Mucopolysaccharidoses (MPSs) are rare congenital lysosomal storage disorders due to a deficiency of enzymes metabolising glycosaminoglycans, leading to their accumulation in tissues. This multisystem disease often requires surgical intervention, including valvular cardiac surgery. Adult MPSs have complex airways making anaesthesia risky. We report novel three-dimensional (3D) modelling airway assessments and multidisciplinary peri-operative airway management. Five MPS adults underwent cardiac surgery at the national MPS cardiac centre (type I = 4, type II = 1; ages 20, 24, 33, 35, 37 years; two males, three females). All had complex airway abnormalities. Assessments involved examination, nasendoscopy, imaging, functional studies, 3D reconstruction, virtual endoscopy, virtual reality and simulation using computerised, physical modelling. Awake oral fibre-optic intubation was achieved via airway conduit. Staged extubation was performed on the first post-operative day under laryngo-tracheoscopic guidance. The post-operative period involved chest physiotherapy and occupational therapy. All patients had safe intubation, ventilation and extubation. Four had good cardiac surgical outcomes, one (MPS type I; age 35 years) was inoperable due to endocarditis. None had post-operative airway complications. Expertise from cardiovascular-heart team, multidisciplinary airway management, use of novel techniques is vital. Traditional airway assessments are insufficient, so ENT input, radiology and computerised methods to assess and simulate the airway in 3D by collaboration with clinical engineering is essential.
PubMed: 38592237
DOI: 10.3390/jcm13051366 -
Molecular Therapy : the Journal of the... Jun 2024Gene therapy in hematopoietic stem and progenitor cells (HSPCs) shows great potential for the treatment of inborn metabolic diseases. Typical HSPC gene therapy...
Gene therapy in hematopoietic stem and progenitor cells (HSPCs) shows great potential for the treatment of inborn metabolic diseases. Typical HSPC gene therapy approaches rely on constitutive promoters to express a therapeutic transgene, which is associated with multiple disadvantages. Here, we propose a novel promoterless intronic gene editing approach that triggers transgene expression only after cellular differentiation into the myeloid lineage. We integrated a splicing-competent eGFP cassette into the first intron of CD11b and observed expression of eGFP in the myeloid lineage but minimal to no expression in HSPCs or differentiated non-myeloid lineages. In vivo, edited HSPCs successfully engrafted in immunodeficient mice and displayed transgene expression in the myeloid compartment of multiple tissues. Using the same approach, we expressed alpha-L-iduronidase (IDUA), the defective enzyme in Mucopolysaccharidosis type I, and observed a 10-fold supraendogenous IDUA expression exclusively after myeloid differentiation. Edited cells efficiently populated bone marrow, blood, and spleen of immunodeficient mice, and retained the capacity to secrete IDUA ex vivo. Importantly, cells edited with the eGFP and IDUA transgenes were also found in the brain. This approach may unlock new therapeutic strategies for inborn metabolic and neurological diseases that require the delivery of therapeutics in brain.
Topics: Animals; Gene Editing; Transgenes; Mice; Hematopoietic Stem Cells; Introns; Humans; Myeloid Cells; Transcription Activator-Like Effector Nucleases; Cell Differentiation; Genetic Therapy; Iduronidase; Green Fluorescent Proteins; Gene Expression; Cell Lineage; CD11b Antigen; Hematopoietic Stem Cell Transplantation; Mucopolysaccharidosis I
PubMed: 38582963
DOI: 10.1016/j.ymthe.2024.04.001 -
Journal of Children's Orthopaedics Apr 2024Literature regarding total hip arthroplasty for pediatric hip diseases is scarce. This review aims to portray the various orthopedic conditions of childhood that can... (Review)
Review
PURPOSE
Literature regarding total hip arthroplasty for pediatric hip diseases is scarce. This review aims to portray the various orthopedic conditions of childhood that can lead to significant impairment of the hip joint and, ultimately, to total hip arthroplasty in adolescence and adulthood.
METHODS
In total, 61 out of 3666 articles were selected according to (1) the diagnosis of one of the 12 pediatric hip pathologies (Legg-Perthes-Calvé disease, developmental dysplasia of the hip, slipped capital femoral epiphysis, neuromuscular hip dysplasia, post-traumatic avascular necrosis of the proximal femur, juvenile rheumatoid arthritis, achondroplasia, spondyloepiphyseal dysplasia, mucopolysaccharidosis, mucolipidosis, hip infections, and tumors) that required total hip arthroplasty; (2) minimum follow-up of 16 months; (3) assessed outcome with a clinical or radiologic score; (4) Methodological Items for Non-Randomized Studies quality score of 9 or higher. The following information for each pathology was retrieved: mean age at total hip arthroplasty, reason for total hip arthroplasty, type of total hip arthroplasty, surgical technique, mean follow-up, and outcomes.
RESULTS
Overall, the mean age at total hip arthroplasty for pediatric hip disease is in the sixth and seventh decade, except for tumors and skeletal dysplasias. The reason for performing total hip arthroplasty is often osteoarthrosis and abnormal anatomy. Prosthesis types change based on patient's conditions and technological advances; custom-made implants are used for tumors, juvenile rheumatoid arthritis, and skeletal dysplasias; for other diseases, the most frequent are modular cementless implants. Outcomes are generally good, and all studies portray functional and pain improvements.
CONCLUSION
Total hip arthroplasty is performed more frequently than in the past in patients with pediatric hip pathologies; it enhances patients' quality of life by reducing pain and improving function. However, revision rate in these patients is not negligible.
PubMed: 38567046
DOI: 10.1177/18632521241229608 -
The Indian Journal of Radiology &... Apr 2024Skeletal dysplasias or osteochondrodysplasias comprise a large heterogeneous group of genetic disorders and possess significant overlap on imaging, which adds to the... (Review)
Review
Skeletal dysplasias or osteochondrodysplasias comprise a large heterogeneous group of genetic disorders and possess significant overlap on imaging, which adds to the dilemma of the reporting radiologist. These entities are routinely evaluated with a detailed skeletal survey and hand radiographs form a crucial part of a complete survey. Certain conditions have characteristic imaging findings that enable a diagnosis be made on hand radiograph alone. Additionally, hand radiographs may also demonstrate findings that may be suggestive of a particular diagnosis/differential diagnoses and would warrant further assessment for proving the same. We aim to demonstrate the use of hand radiographs in diagnosis of various such entities through this review. Although they cannot replace a complete skeletal survey in the diagnosis, hand radiographs performed for other indications might alert a radiologist to the diagnosis of an unsuspected skeletal dysplasia.
PubMed: 38549896
DOI: 10.1055/s-0043-1777320