Siblings with MAN1B1-CDG Showing Novel Biochemical Profiles

Analysis of carbohydrates and glycoconjugates by matrix-assisted laser desorption/ionization mass spectrometry: An update for 2021-2022

The use of matrix-assisted laser desorption/ionization (MALDI) mass spectrometry for the analysis of carbohydrates and glycoconjugates is a well-established technique and this review is the 12th update of the original article published in 1999 and brings coverage of the literature to the end of 2022. As with previous review, this review also includes a few papers that describe methods appropriate to analysis by MALDI, such as sample preparation, even though the ionization method is not MALDI. The review follows the same format as previous reviews. It is divided into three sections: (1) general aspects such as theory of the MALDI process, matrices, derivatization, MALDI imaging, fragmentation, quantification and the use of computer software for structural identification. (2) Applications to various structural types such as oligo- and polysaccharides, glycoproteins, glycolipids, glycosides and biopharmaceuticals, and (3) other general areas such as medicine, industrial processes, natural products and glycan synthesis where MALDI is extensively used. Much of the material relating to applications is presented in tabular form. MALDI is still an ideal technique for carbohydrate analysis, particularly in its ability to produce single ions from each analyte and advancements in the technique and range of applications show little sign of diminishing.

Congenital disorders of glycosylation and infantile epilepsy

Congenital disorders of glycosylation (CDG) are a group of rare inherited metabolic disorders caused by defects in various defects of protein or lipid glycosylation pathways. The symptoms and signs of CDG usually develop in infancy. Epilepsy is commonly observed in CDG individuals and is often a presenting symptom. These epilepsies can present across the lifespan, share features of refractoriness to antiseizure medications, and are often associated with comorbid developmental delay, psychomotor regression, intellectual disability, and behavioral problems. In this review, we discuss CDG and infantile epilepsy, focusing on an overview of clinical manifestations and electroencephalographic features. Finally, we propose a tiered approach that will permit a clinician to systematically investigate and identify CDG earlier, and furthermore, to provide genetic counseling for the family.

Pathophysiological Mechanism of Neurodevelopmental Disorders-Overview

Technological advancements in next-generation DNA sequencing have enabled elucidation of many genetic causes of neurodevelopmental disorders (NDDs) over the last two decades [...].

Case Report: Compound Heterozygous Variants of the MAN1B1 Gene in a Russian Patient with Rafiq Syndrome

Rafiq syndrome (RAFQS) is a congenital disorder of glycosylation (CDG) that is caused by mutations in the MAN1B1 gene and characterized by impaired protein and lipid glycosylation. RAFQS is characterized by a delay in intellectual and motor development, facial and other dysmorphism, truncal obesity, behavior problems, and hypotonia. We describe a Russian patient with delayed intellectual and motor development, a lack of speech, disorientation in space and time, impaired attention and memory, and episodes of aggression. Screening for lysosomal, amino acid, organic acid, and mitochondrial disorders was normal. The patient was referred for the targeted sequencing of the “Hereditary Metabolic Disorders” panel. The genetic testing revealed two heterozygous pathogenic variants in the MAN1B1 gene: the previously reported c.1000C > T (p.Arg334Cys) and the novel c.1065 + 1 G > C. Thus, the patient’s clinical picture and genetic analysis confirmed RAFQS in the patient.

Identification of MAN1B1 as a Novel Marker for Bladder Cancer and Its Relationship with Immune Cell Infiltration

Bladder cancer (BC) is a common malignant tumor of the genitourinary system, and there are not enough tumor biomarker tests that are specific, trustworthy, and noninvasive for the diagnosis and prognosis. The purpose of this study is to investigate the clinical relevance, prognostic value, and immunological signature of Mannosidase alpha class 1B member 1(MAN1B1) expressions in BC. The Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression (GTEx) databases provided the raw information that was used to analyze the expression of MAN1B1 in tumor patients. Then, a statistical study was carried out to assess the correlations of MAN1B1 expression with the clinical characteristics and the prognosis of BC. The correlation between MAN1B1 expression and tumor immune infiltration was explored via single-sample gene set enrichment analysis (ssGSEA). In human cancers, MAN1B1 expressions were shown to be generally higher in tumors than in normal specimens. We confirmed that MAN1B1 expression was distinctly increased in BC specimens compared with nontumor specimens. BC specimens with advanced T stage and M stage showed a higher level of MAN1B1. Survival analysis revealed that the overall survival (OS), disease-specific survival (DSS), and progression-free interval (PFI) of patients with high MAN1B1 expressions were distinctly worse than those with low MAN1B1 expressions. Importantly, multivariate analyses only confirmed that MAN1B1 expression was an independent prognostic factor for OS of the patients with BC. Furthermore, we observed that MAN1B1 expression level was significantly correlated with abundance of multiple immune infiltrates including Th2 cells, macrophages, Th1 cells, neutrophils, T helper cells, and NK CD56 bright cells. In conjunction with all of these findings, elevated MAN1B1 expression is associated with a poor prognosis and a higher number of immune cells in BC. MAN1B1 has the potential to act as a biomarker that can evaluate both the patient's prognosis and the degree of immune infiltration in BC.