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Zhonghua Yi Xue Yi Chuan Xue Za Zhi =... Mar 2024To explore the clinical and genetic characteristics of a neonate with Microvillus inclusion disease (MVID). (Review)
Review
OBJECTIVE
To explore the clinical and genetic characteristics of a neonate with Microvillus inclusion disease (MVID).
METHODS
A neonate with MVID admitted to the First Affiliated Hospital of Zhengzhou University in May 2019 was selected as the study subject. Clinical data were collected. Whole exome sequencing (WES) was carried out, and candidate variants were verified by Sanger sequencing and multiple ligation-dependent probe amplification (MLPA). A literature was also carried out to summarize the clinical and genetic characteristics of MVID.
RESULTS
The prematurely born neonate had presented with unexplained refractory diarrhea and metabolic acidosis. Active symptomatic treatment was ineffective, and the child had died at 2 months old. WES revealed that he had harbored compound heterozygous variants of the MYO5B gene, namely c.1591C>T (p.R531W) and deletion of exon 9. Sanger sequencing showed that the R531W variant was inherited form his father, and MLPA confirmed that the exon 9 deletion was inherited from his mother. Seven children with MVID were reported in China, of which one was lost during follow-up and six had deceased. One hundred eighty eight patients were reported worldwide and only one was cured. The clinical features of MVID had included refractory diarrhea, metabolic acidosis and poor prognosis.
CONCLUSION
The child was diagnosed with MVID due to the compound heterozygous variants of the MYO5B gene, which has provided a basis for genetic counseling and prenatal diagnosis.
Topics: Female; Humans; Infant; Infant, Newborn; Male; Pregnancy; Acidosis; Diarrhea; Malabsorption Syndromes; Microvilli; Mucolipidoses; Myosin Heavy Chains; Myosin Type V
PubMed: 38448026
DOI: 10.3760/cma.j.cn511374-20221117-00796 -
JIMD Reports Mar 2024Mucopolysaccharidoses (MPS) screening is tedious and still performed by analysis of total glycosaminoglycans (GAG) using 1,9-dimethylmethylene blue (DMB) photometric...
Mucopolysaccharidoses (MPS) screening is tedious and still performed by analysis of total glycosaminoglycans (GAG) using 1,9-dimethylmethylene blue (DMB) photometric assay, although false positive and negative tests have been reported. Analysis of differentiated GAGs have been pursued classically by gel electrophoresis or more recently by quantitative LC-MS assays. Secondary elevations of GAGs have been reported in urinary tract infections (UTI). In this manuscript, we describe the diagnostic accuracy of urinary GAG measurements by LC-MS for MPS typing in 68 untreated MPS and mucolipidosis (ML) patients, 183 controls and 153 UTI samples. We report age-dependent reference values and cut-offs for chondroitin sulfate (CS), dermatan sulfate (DS), heparan sulfate (HS) and keratan sulfate (KS) and specific GAG ratios. The use of HS/DS ratio in combination to GAG concentrations normalized to creatinine improves the diagnostic accuracy in MPS type I, II, VI and VII. In total 15 samples classified to the wrong MPS type could be correctly assigned using HS/DS ratio. Increased KS/HS ratio in addition to increased KS improves discrimination of MPS type IV by excluding false positives. Some samples of UTI patients showed elevation of specific GAGs, mainly CS, KS and KS/HS ratio and could be misclassified as MPS type IV. Finally, DMB photometric assay performed in MPS and ML samples reveal four false negative tests (sensitivity of 94%). In conclusion, specific GAG ratios in complement to quantitative GAG values obtained by LC-MS enhance discrimination of MPS types. Exclusion of patients with UTI improve diagnostic accuracy in MPS IV but not in other types.
PubMed: 38444580
DOI: 10.1002/jmd2.12412 -
JIMD Reports Mar 2024Lysosomal storage disorders (LSDs) in adults have milder phenotype and variable age at presentation. Several studies have described the phenotype, genotype and treatment...
Lysosomal storage disorders (LSDs) in adults have milder phenotype and variable age at presentation. Several studies have described the phenotype, genotype and treatment outcomes for adult-onset LSDs like Gaucher, Fabry, Pompe disease and others. We describe the first systematic study on the occurrence of LSDs in an adult population from India. It describes, the key clinical signs seen in these patients and those from literature review that can aid in early detection. Of 2102 biochemically diagnosed LSDs cases, 32 adult patients were identified with LSDs. Based on the clinical suspicion, screening test and enzyme study was carried out. Twenty-two patients were subjected to a genetic study to identify the causative variant in a respective gene. Of the 32 adult patients, we observed a maximum percentage of 37.5% ( = 12) cases with Gaucher disease, followed by 13% ( = 4) with Fabry disease. We found 10% of cases with MPS IVA and MPS I, and 9% cases with Pompe. Single case of adult mucolipidosis III and two cases each of Type 1 Sialidosis, Niemann-Pick disease B and metachromatic leukodystrophy were identified. We observed two common variants p.Leu483Pro and p.Ala487Thr in the gene in 23% of Indian patients with adult Gaucher disease. No common variants were observed in other aforementioned LSDs. Study identified 50% of Fabry patients and 4% of Gaucher patients diagnosed at our centre to be adults. The prevalence of adult Pompe patients was low (3.4%) as compared to 80% reported in the Caucasian population. Adult LSDs such as, MPS III, GM1/GM2 gangliosidosis and Krabbe disease were not identified in our cohort.
PubMed: 38444573
DOI: 10.1002/jmd2.12407 -
Indian Journal of Pediatrics Feb 2024I-cell disease (Mucolipidosis Type II) is a rare lysosomal storage disorder caused by GNPTAB gene defects, leading to severe morbidity and mortality. The authors present...
I-cell disease (Mucolipidosis Type II) is a rare lysosomal storage disorder caused by GNPTAB gene defects, leading to severe morbidity and mortality. The authors present the case of a neonate born at 38 wk gestational age, with suspected skeletal dysplasia during pregnancy and a complex clinical and laboratory presentation after birth. This is a rare case, and its diagnosis was made through placental pathology, which revealed the condition called mucolipidosis Type II. To the best of authors' knowledge, this is one of the few cases diagnosed in the neonatal period with placental pathology globally and the first in Canada, highlighting the significance of placental pathology for the diagnosis of these rare conditions and future counseling of the parents. In conclusion, mucolipidosis Type II is a rare condition in neonates. Early diagnosis in neonates can be made through placental pathology for parental counseling.
PubMed: 38376646
DOI: 10.1007/s12098-024-05073-6 -
Gene Therapy May 2024Patients with sialidosis (mucolipidosis type I) type I typically present with myoclonus, seizures, ataxia, cherry-red spots, and blindness because of mutations in the...
Patients with sialidosis (mucolipidosis type I) type I typically present with myoclonus, seizures, ataxia, cherry-red spots, and blindness because of mutations in the neuraminidase 1 (NEU1) gene. Currently, there is no treatment for sialidosis. In this study, we developed an adeno-associated virus (AAV)-mediated gene therapy for a Neu1 knockout (Neu1) mouse model of sialidosis. The vector, AAV9-P3-NP, included the human NEU1 promoter, NEU1 cDNA, IRES, and CTSA cDNA. Untreated Neu1 mice showed astrogliosis and microglial LAMP1 accumulation in the nervous system, including brain, spinal cord, and dorsal root ganglion, together with impaired motor function. Coexpression of NEU1 and protective protein/cathepsin A (PPCA) in neonatal Neu1 mice by intracerebroventricular injection, and less effective by facial vein injection, decreased astrogliosis and LAMP1 accumulation in the nervous system and improved rotarod performance of the treated mice. Facial vein injection also improved the grip strength and survival of Neu1 mice. Therefore, cerebrospinal fluid delivery of AAV9-P3-NP, which corrects the neurological deficits of mice with sialidosis, could be a suitable treatment for patients with sialidosis type I. After intracerebroventricular or facial vein injection of AAV vectors, NEU1 and PPCA are expressed together. PPCA-protected NEU1 is then sent to lysosomes, where β-Gal binds to this complex to form a multienzyme complex in order to execute its function.
Topics: Animals; Genetic Therapy; Neuraminidase; Mice; Dependovirus; Mucolipidoses; Mice, Knockout; Genetic Vectors; Disease Models, Animal; Cathepsin A; Humans; Brain
PubMed: 38321198
DOI: 10.1038/s41434-024-00443-3 -
Cellular and Molecular Gastroenterology... 2024Microvillus inclusion disease (MVID) is a rare condition that is present from birth and affects the digestive system. People with MVID experience severe diarrhea that is... (Review)
Review
Microvillus inclusion disease (MVID) is a rare condition that is present from birth and affects the digestive system. People with MVID experience severe diarrhea that is difficult to control, cannot absorb dietary nutrients, and struggle to grow and thrive. In addition, diverse clinical manifestations, some of which are life-threatening, have been reported in cases of MVID. MVID can be caused by variants in the MYO5B, STX3, STXBP2, or UNC45A gene. These genes produce proteins that have been functionally linked to each other in intestinal epithelial cells. MVID associated with STXBP2 variants presents in a subset of patients diagnosed with familial hemophagocytic lymphohistiocytosis type 5. MVID associated with UNC45A variants presents in most patients diagnosed with osteo-oto-hepato-enteric syndrome. Furthermore, variants in MYO5B or STX3 can also cause other diseases that are characterized by phenotypes that can co-occur in subsets of patients diagnosed with MVID. Recent studies involving clinical data and experiments with cells and animals revealed connections between specific phenotypes occurring outside of the digestive system and the type of gene variants that cause MVID. Here, we have reviewed these patterns and correlations, which are expected to be valuable for healthcare professionals in managing the disease and providing personalized care for patients and their families.
Topics: Humans; Mucolipidoses; Microvilli; Malabsorption Syndromes; Phenotype; Animals; Myosin Type V; Mutation; Genetic Predisposition to Disease
PubMed: 38307491
DOI: 10.1016/j.jcmgh.2024.01.015 -
Pediatrics and Neonatology Mar 2024
Topics: Female; Humans; Hydrops Fetalis; Mucolipidoses
PubMed: 38296756
DOI: 10.1016/j.pedneo.2022.05.023 -
American Journal of Medical Genetics.... Jun 2024Mucolipidosis type-II (ML-II) is an ultra-rare disorder caused by deficiency of N-acetylglucosaminyl-1-phosphotransferase enzyme due to biallelic pathogenic variants in...
Mucolipidosis type-II (ML-II) is an ultra-rare disorder caused by deficiency of N-acetylglucosaminyl-1-phosphotransferase enzyme due to biallelic pathogenic variants in GNPTAB gene. There are a few known about the natural history of ML-II. In this study, we presented the natural course of 24 patients diagnosed with ML-II. Mean age at diagnosis was 9.3 ± 5.7 months. All patients had coarse face, developmental delay, and hypotonia. The mean survival time was 3.01 ± 1.4 years. The oldest patient was 6.5 years old. Twelve patients died due to lung infection and respiratory failure. We observed early and significant radiological findings of ML-II were different from typical dysostosis multiplex such as femoral cloaking, rickets-like changes, and talocalcaneal stippling. These are significant findings observed in the fetal or newborn period which is considered to be highly characteristic of ML-II and disappears in the first year. Cloaking, rickets-like changes, and stippling were not observed in patients older than three months of age and this suggests that these findings disappear within the first year. These radiological features can be used as important clues for diagnosis. We detected eight different pathogenic variants in GNPTAB gene, three of them were novel.
Topics: Humans; Mucolipidoses; Male; Female; Infant; Child, Preschool; Child; Transferases (Other Substituted Phosphate Groups); Mutation; Radiography; Early Diagnosis; Infant, Newborn; Phenotype
PubMed: 38264826
DOI: 10.1002/ajmg.a.63545 -
Glycoconjugate Journal Dec 2023Neuraminidase 1 (NEU1) is a lysosomal sialidase that cleaves terminal α-linked sialic acid residues from sialylglycans. NEU1 is biosynthesized in the rough endoplasmic... (Review)
Review
Neuraminidase 1 (NEU1) is a lysosomal sialidase that cleaves terminal α-linked sialic acid residues from sialylglycans. NEU1 is biosynthesized in the rough endoplasmic reticulum (RER) lumen as an N-glycosylated protein to associate with its protective protein/cathepsin A (CTSA) and then form a lysosomal multienzyme complex (LMC) also containing β-galactosidase 1 (GLB1). Unlike other mammalian sialidases, including NEU2 to NEU4, NEU1 transport to lysosomes requires association of NEU1 with CTSA, binding of the CTSA carrying terminal mannose 6-phosphate (M6P)-type N-glycan with M6P receptor (M6PR), and intralysosomal NEU1 activation at acidic pH. In contrast, overexpression of the single NEU1 gene in mammalian cells causes intracellular NEU1 protein crystallization in the RER due to self-aggregation when intracellular CTSA is reduced to a relatively low level. Sialidosis (SiD) and galactosialidosis (GS) are autosomal recessive lysosomal storage diseases caused by the gene mutations of NEU1 and CTSA, respectively. These incurable diseases associate with the NEU1 deficiency, excessive accumulation of sialylglycans in neurovisceral organs, and systemic manifestations. We established a novel GS model mouse carrying homozygotic Ctsa IVS6 + 1 g/a mutation causing partial exon 6 skipping with simultaneous deficiency of Ctsa and Neu1. Symptoms developed in the GS mice like those in juvenile/adult GS patients, such as myoclonic seizures, suppressed behavior, gargoyle-like face, edema, proctoptosis due to Neu1 deficiency, and sialylglycan accumulation associated with neurovisceral inflammation. We developed a modified NEU1 (modNEU1), which does not form protein crystals but is transported to lysosomes by co-expressed CTSA. In vivo gene therapy for GS and SiD utilizing a single adeno-associated virus (AAV) carrying modNEU1 and CTSA genes under dual promoter control will be created.
Topics: Animals; Humans; Mice; Neuraminidase; Mucolipidoses; Lysosomes; Mammals; Lysosomal Storage Diseases
PubMed: 38147151
DOI: 10.1007/s10719-023-10135-6 -
Bioorganic & Medicinal Chemistry Letters Jan 2024Screening a library of >100,000 compounds identified the substituted tetrazole compound 1 as a selective TRPML1 agonist. Both enantiomers of compound 1 were separated...
Screening a library of >100,000 compounds identified the substituted tetrazole compound 1 as a selective TRPML1 agonist. Both enantiomers of compound 1 were separated and profiled in vitro and in vivo. Their selectivity, ready availability and CNS penetration should enable them to serve as the tool compounds of choice in future TRPML1 channel activation studies. SAR studies on conformationally locked macrocyclic analogs further improved the TRPML1 agonist potency while retaining the selectivity.
Topics: Transient Receptor Potential Channels; Structure-Activity Relationship; Tetrazoles
PubMed: 38141860
DOI: 10.1016/j.bmcl.2023.129595