SLC37A4-CDG: Second patient.
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ABSTRACT:
SUBMITTER: Wilson MP
PROVIDER: S-EPMC7932867 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:The conserved oligomeric Golgi (COG) complex is a hetero-octameric complex essential for normal glycosylation and intra-Golgi transport. An increasing number of congenital disorder of glycosylation type II (CDG-II) mutations are found in COG subunits indicating its importance in glycosylation. We report a new CDG-II patient harbouring a p.R729W missense mutation in COG4 combined with a submicroscopical deletion. The resulting downregulation of COG4 expression additionally affects expression or stability of other lobe A subunits. Despite this, full complex formation was maintained albeit to a lower extent as shown by glycerol gradient centrifugation. Moreover, our data indicate that subunits are present in a cytosolic pool and full complex formation assists tethering preceding membrane fusion. By extending this study to four other known COG-deficient patients, we now present the first comparative analysis on defects in transport, glycosylation and Golgi ultrastructure in these patients. The observed structural and biochemical abnormalities correlate with the severity of the mutation, with the COG4 mutant being the mildest. All together our results indicate that intact COG complexes are required to maintain Golgi dynamics and its associated functions. According to the current CDG nomenclature, this newly identified deficiency is designated CDG-IIj.
| S-EPMC2722986 | biostudies-literature
Project description:ABSTRACT For the first time the glycosylation of a patient with a MPI‐CDG during pregnancy is monitored. MPI‐CDG, is characterised by a deficiency in mannose‐6‐phosphate isomerase (MPI) leading to a reduced pool of glycosylation precursors, impairing the biosynthesis of N‐glycans leading to N‐glycosylation defects. The abnormal N‐glycosylation profile with an elevation of asialotransferrin and disialotransferrin, typical of CDG type I, is assessable by transferrin isoelectrofocusing. Oral D‐mannose supplementation for MPI‐CDG patients has been widely used and improves clinical manifestations. The glycosylation of a MPI‐CDG patient during pregnancy without mannose supplementation was studied using carbohydrate deficient transferrin (CDT) assay, transferrin isoelectrofocusing (IEF) and mass spectrometry of total serum N‐glycans. A general improvement of the glycosylation profile of the patient due to a better transfer of the glycan precursors as well as an increase of the triantennary glycans (and sialylation) was observed. In conclusion, in the absence of mannose supplementation, the previously observed glycosylation abnormality of the MPI‐CDG patient was corrected. The molecular mechanism underlying this N‐glycosylation rescue during MPI‐CDG pregnancy further needs to be investigated.
| S-EPMC8574185 | biostudies-literature
Project description:Background: SRD5A3-CDG is a rare N-glycosylation defect caused by steroid 5 alpha reductase type 3 deficiency. Its key feature is an early severe visual impairment with variable ocular anomalies often leading to diagnosis. Additional symptoms are still poorly defined. In this case study, we discuss 11 genetically confirmed cases, and report on emerging features involving other systems in addition to the eye phenotype. Methods: In total, 11 SRD5A3-CDG patients in five sets of sibships were included in the study. Data on 9 of 11 patients are as of yet unpublished. Patients' results on biochemical and genetic investigations and on in-depth phenotyping are presented. Results: Key diagnostic features of SRD5A3-CDG are ophthalmological abnormalities with early-onset retinal dystrophy and optic nerve hypoplasia. SRD5A3-CDG is also characterized by variable neurological symptoms including intellectual disability, ataxia, and hypotonia. Furthermore, ichthyosiform skin lesions, joint laxity, and scoliosis have been observed in our cohort. We also report additional findings including dystonia, anxiety disorder, gastrointestinal symptoms, and MRI findings of small basal ganglia and mal-rotated hippocampus, whereas previous publications described dysmorphic features as a common finding in SRD5A3, which could not be confirmed in our patient cohort. Conclusion: The detailed description of the phenotype of this large cohort of patients with SRD5A3-CDG highlights that the key clinical diagnostic features of SRD5A3-CDG are an early onset form of ophthalmological problems in patients with a multisystem disorder with variable symptoms evolving over time. This should aid earlier diagnosis and confirms the need for long-time follow-up of patients.
| S-EPMC8671882 | biostudies-literature
Project description:We report a Korean patient with glycogen storage disease type 1b (GSD-1b) whose diagnosis was confirmed by liver biopsy and laboratory results. The patient presented with delay of puberty and short stature on admission and had typical clinical symptoms of GSD as well as chronic neutropenia and inflammatory bowel disease. Mutation analysis of the glucose 6-phosphate translocase 6-phosphate translocase (SLC37A4) gene revealed that the patient was a compound heterozygote of two different mutations including a deletion mutation (c.1042_1043delCT; L348fs) and a missense mutation (A148V). The L348fs mutation was inherited from the patient's father and has been reported in an Italian family with GSD-1b, while the A148V mutation was transmitted from the patient's mother and was a novel mutation. To the best of our knowledge, this is the first report of genetically confirmed case of GSD-1b in Korean.
| S-EPMC2782211 | biostudies-literature
Project description:BackgroundMolecular techniques are fundamental for establishing an accurate diagnosis and therapeutic approach of glycogen storage diseases (GSDs). We aimed to evaluate SLC37A4 mutation spectrum in Korean GSD Ib patients.MethodsNine Korean patients from eight unrelated families with GSD Ib were included. SLC37A4 mutations were detected in all patients with direct sequencing using a PCR method and/or whole-exome sequencing. A comprehensive review of previously reported SLC37A4 mutations was also conducted.ResultsNine different pathogenic SLC37A4 mutations were identified in the nine patients with GSD Ib. Among them, four novel mutations were identified: c.148G>A (pGly50Arg), c.320G>A (p.Trp107*), c.412T>C (p.Trp138Arg), and c.818G>A (p.Gly273Asp). The most common mutation type was missense mutations (66.7%, 6/9), followed by nonsense mutations (22.2%, 2/9) and small deletion mutations (11.1%, 1/9). The most common mutation identified in the Korean population was c.443C>T (p.Ala148Val), which comprised 39.9% (7/18) of all tested alleles. This mutation has not been reported in GSD Ib patients in other ethnic populations.ConclusionsThis study expands knowledge of the SLC37A4 mutation spectrum in Korean patients with GSD Ib.
| S-EPMC5339099 | biostudies-literature
Project description:A boy presented at the age of 3.5 months with a developmental delay. He developed infantile spasms with hypsarrhytmia on EEG 1 month later. Additional symptoms were delayed visual development, asymmetrical hearing loss, hypotonia, and choreoathetoid movements. He also had some dysmorphic features and was vulnerable for infections. He was treated successively with vigabatrin, prednisolone, valproic acid, nitrazepam, and lamotrigine without a lasting clinical effect, but showed a treatment response to levetiracetam. Cerebral MRI showed hypoplasia of the corpus callosum and a mild delay in myelination. Further investigations including metabolic screening and glycosylation studies by transferrin isoelectric focusing were all considered to be normal. Whole-exome sequencing identified a de novo mutation in the ALG13 gene (c.320A>G, p.(Asn107Ser)). Mutations in this gene, which is located on the X-chromosome, are associated with congenital disorders of glycosylation type I (CDG-I). Mass spectrometric analysis of transferrin showed minor glycosylation abnormalities. The c.320A>G mutation in ALG13 has until now only been described in girls and was thought to be lethal for boys. All girls with this specific mutation presented with a similar phenotype of developmental delay and severe early onset epilepsy. In two girls glycosylation studies were performed which showed a normal glycosylation pattern. This is the first boy presenting with an epileptic encephalopathy caused by the c.320A>G mutation in the ALG13 gene. Since glycosylation studies are near-normal in patients with this mutation, the diagnosis of ALG13-CDG can be missed if genetic studies are not performed.
| S-EPMC6122024 | biostudies-other
Project description:BACKGROUND:Congenital disorder of glycosylation (CDG) type I is a group of rare disorders caused by recessive mutations in up to 25 genes that impair the N-glycan precursor formation and its transfer to proteins resulting in hypoglycosylation of multiple proteins. Congenital disorder of glycosylation causes multisystem defects usually with psychomotor delay that is diagnosed in the infancy. We aim to supply further evidences supporting that CDG may be underestimated. METHODS:Antithrombin and factor XI were studied by chromogenic and coagulometric methods. Hypoglycosylation of plasma proteins was evaluated by western blot, HPLC, Q-TOF, and RP-LC-MRM-MS. Genetic analysis included whole exome, Sanger sequencing, and PCR-allele specific assay. RESULTS:We here present an intriguing patient with an exceptional phenotype: 25-year-old women with a ventricular septal defect and severe idiopathic scoliosis but no facial dysmorphism, who dances as a professional, and has a University degree. Congenital disorder of glycosylation diagnosis started through the identification of antithrombin deficiency without SERPINC1 defect and the detection of hypoglycosylated forms. Increased levels of hypoglycosylated forms of F XI (also with significant deficiency) and transferrin were also detected. Whole exome analysis showed a novel homozygous ALG12 variant c.77T>A, p.(Val26Asp) supporting an ALG12-CDG diagnosis. It also showed three new variants in KMT2D, and a mild, known ALG6 variant. CONCLUSIONS:This novel ALG12-CDG patient (the 13th reported) underlines the heterogeneity of this CDG and broadens its phenotypical spectrum, supports that these disorders are underestimated, and suggests that combination of global hypoglycosylation with specific gene defects might determine the clinical manifestations of CDG patients.
| S-EPMC7434597 | biostudies-literature
Project description:Pattern recognition, using a group of characteristic, or discriminating features, is a powerful tool in metabolic diagnostic. A classic example of this approach is used in biochemical analysis of urine organic acid analysis, where the reporting depends more on the correlation of pertinent positive and negative findings, rather than on the absolute values of specific markers. Similar uses of pattern recognition in the field of biochemical genetics include the interpretation of data obtained by metabolomics, like glycomics, where a recognizable pattern or the presence of a specific glycan sub-fraction can lead to the direct diagnosis of certain types of congenital disorders of glycosylation. Another indispensable tool is the use of clinical pattern recognition-or syndromology-relying on careful phenotyping. While genomics might uncover variants not essential in the final clinical expression of disease, and metabolomics could point to a mixture of primary but also secondary changes in biochemical pathways, phenomics describes the clinically relevant manifestations and the full expression of the disease. In the current review we apply phenomics to the field of congenital disorders of glycosylation, focusing on recognizable differentiating findings in glycosylation disorders, characteristic dysmorphic features and malformations in PMM2-CDG, and overlapping patterns among the currently known glycosylation disorders based on their pathophysiological basis.
| S-EPMC5960425 | biostudies-literature
Project description:A recent gamma-retroviral clinical Chronic Granulomatous Disease (CGD) gene therapy (GT) trial achieved proof-of-concept but was accompanied by activation of oncogenes and transgene silencing. The ubiquitous chromatin opening element (UCOE) comprises the sequences of two divergently oriented house-keeping gene promoters and is known to have anti-silencing properties. In a screen we identified two novel UCOE constructs that prevent adjacent promoter methylation in P19 cells. Experiments were continued with the shorter UCOE constructs in induced pluripotent stem cells (iPSC) derived from a p47phox-deficient CGD patient. The iPSC line was transduced with the lentiviral GT vectors expressing P47 under the constitutively active SFFV promoter with UCOE element (UCOE_SF) and without UCOE element (SF) adjacent to the SFFV promoter. The iPSC were expanded before propagation towards neutrophils. 20 days after transduction the UCOE_SF vector was protected from methylation in iPSC as previously shown in P19 cells, whereas the SF vector was heavily methylated in iPSC. The UCOE_SF vector maintained stable transgene expression in iPSC, macrophages and neutrophils, whereas the SF vector was strongly silenced. The UCOE_SF vector stably restored ROS production in neutrophils, whereas for the SF vector the count of ROS producing cells was marginal. To conclude, we have shown that the prevention of transgene silencing by UCOE is functionally and mechanistically preserved upon terminal neutrophil differentiation.
| S-EPMC6472893 | biostudies-literature
Project description:BackgroundAlthough patient-driven second opinions are increasingly sought in oncology, the desirability of this trend remains unknown. Therefore, this systematic review assesses evidence on the motivation for and frequency of requests for second opinions and examines how they evolve and their consequences for oncological practice.Materials and methodsRelevant databases were sought using the terms "cancer," "second opinion," and "self-initiated." Included were peer-reviewed articles that reported on patient-initiated second opinions within oncology. Selection, data extraction, and quality assessment were performed and discussed by two researchers.ResultsOf the 25 included studies, the methodological designs were qualitative (n?=?4), mixed (n?=?1), or quantitative (n?=?20). Study quality was rated high for 10 studies, moderate for eight, and low for seven studies. Reported rates of second opinion seeking ranged from 1%-88%. Higher education was most consistently related to seeking a second opinion. Patients' primary motivations were a perceived need for certainty or confirmation, a lack of trust, dissatisfaction with communication, and/or a need for more (personalized) information. Reported rates of diagnostic or therapeutic discrepancies between the first and second opinions ranged from 2%-51%.DiscussionAdditional studies are required to further examine the medical, practical, and psychological consequences of second opinions for patients and oncologists. Future studies could compare the potential advantages and disadvantages of second opinion seeking, and might offer guidance to patients and physicians to better facilitate the second opinion process. Some practical recommendations are provided for oncologists to optimally discuss and conduct second opinions with their patients. The Oncologist 2017;22:1197-1211 IMPLICATIONS FOR PRACTICE: Although cancer patients increasingly seek a second opinion, the benefits of this process remain unclear. Results of this systematic review suggest that the available studies on this topic are highly variable in both methodology and quality. Moreover, reported rates for a second opinion (1%-88%) as well as for disagreement between the first and second opinion (2%-51%) range widely. The primary motivations of patients are a need for certainty, lack of trust, dissatisfaction with communication, and/or a need for more (personalized) information. Additional research should evaluate how unnecessary second opinions might be avoided. Practical suggestions are provided for oncologists to optimize second opinions.
| S-EPMC5634767 | biostudies-literature