Impact of missense mutations in the ALDH7A1 gene on enzyme structure and catalytic function

SummaryType 2B of von Willebrand disease (vWD) refers to qualitative variants with increased affinity of von Willebrand factor (vWF) for platelet glycoprotein Ib (GPIb). All the mutations responsible for type 2B vWD have been located in the A1 domain of vWF. In this study, various recombinant von Willebrand factors (rvWF) reproducing four type 2B vWD missense mutations were compared to wild-type rvWF (WT-rvWF) for their spontaneous binding to platelets and their capacity to induce platelet activation and aggregation. Our data show that the multimeric pattern of each mutated rvWF is similar to that of WT-rvWF but the extent of spontaneous binding and the capacity to induce platelet activation and aggregation are more important for the R543Q and V553M mutations than for the L697V and A698V mutations. Both the binding of mutated rvWFs to platelets and platelet aggregation induced by type 2B rvWFs are inhibited by monoclonal anti-GPIb and anti-vWF antibodies, inhibitors of vWF binding to platelets in the presence of ristocetin, as well as by aurin tricarboxylic acid. On the other hand, EDTA and a monoclonal antibody directed against GPIIb/IIIa only inhibit platelet aggregation. Furthermore, the incubation of type 2B rvWFs with platelets, under stirring conditions, results in the decrease in high molecular weight vWF multimers in solution, the extent of which appears correlated with that of plasma vWF from type 2B vWD patients harboring the corresponding missense mutation. This study supports that the binding of different mutated type 2B vWFs onto platelet GPIb induces various degrees of platelet activation and aggregation and thus suggests that the phenotypic heterogeneity of type 2B vWD may be related to the nature and/or location of the causative point mutation.

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A Novel Mutation Glyl672→Arg in Type 2A and a Homozygous Mutation in Type 2B von Willebrand Disease

Thrombosis and Haemostasis ◽

10.1055/s-0038-1650564 ◽

1996 ◽

Vol 76 (02) ◽

pp. 253-257 ◽

Cited By ~ 14

Author(s):

Takeshi Hagiwara ◽

Hiroshi Inaba ◽

Shinichi Yoshida ◽

Keiko Nagaizumi ◽

Morio Arai ◽

...

Keyword(s):

Missense Mutation ◽

Novel Mutation ◽

Point Mutations ◽

Japanese Patients ◽

Von Willebrand Disease ◽

Homozygous Mutation ◽

Missense Mutations ◽

Reaction Products ◽

Type 3 ◽

Von Willebrand

SummaryGenetic materials from 16 unrelated Japanese patients with von Willebrand disease (vWD) were analyzed for mutations. Exon 28 of the von Willebrand factor (vWF) gene, where point mutations have been found most frequent, was screened by various restriction-enzyme analyses. Six patients were observed to have abnormal restriction patterns. By sequence analyses of the polymerase chain-reaction products, we identified a homozygous R1308C missense mutation in a patient with type 2B vWD; R1597W, R1597Q, G1609R and G1672R missense mutations in five patients with type 2A; and a G1659ter nonsense mutation in a patient with type 3 vWD. The G1672R was a novel missense mutation of the carboxyl-terminal end of the A2 domain. In addition, we detected an A/C polymorphism at nucleotide 4915 with HaeIII. There was no particular linkage disequilibrium of the A/C polymorphism, either with the G/A polymorphism at nucleotide 4391 detected with Hphl or with the C/T at 4891 detected with BstEll.

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Mutation Spectrum in Patients with Wiskott-Aldrich Syndrome and X-linked Thrombocytopenia: Identification of Twelve Different Mutations in the WASP Gene

Thrombosis and Haemostasis ◽

10.1055/s-0038-1650318 ◽

1996 ◽

Vol 75 (04) ◽

pp. 546-550 ◽

Cited By ~ 21

Author(s):

Marianne Schwartz ◽

Albert Békássy ◽

Mikael Donnér ◽

Thomas Hertel ◽

Stefan Hreidarson ◽

...

Keyword(s):

Base Pair ◽

Hot Spot ◽

Missense Mutations ◽

Nucleotide Substitutions ◽

Exon 2 ◽

Wiskott Aldrich Syndrome ◽

Base Pair Deletion ◽

Reliable Diagnosis ◽

Wasp Gene ◽

Detection Of Mutations

SummaryTwelve different mutations in the WASP gene were found in twelve unrelated families with Wiskott-Aldrich syndrome (WAS) or X-linked thrombocytopenia (XLT). Four frameshift, one splice, one nonsense mutation, and one 18-base-pair deletion were detected in seven patients with WAS. Only missense mutations were found in five patients diagnosed as having XLT. One of the nucleotide substitutions in exon 2 (codon 86) results in an Arg to Cys replacement. Two other nucleotide substitutions in this codon, R86L and R86H, have been reported previously, both giving rise to typical WAS symptoms, indicating a mutational hot spot in this codon. The finding of mutations in the WASP gene in both WAS and XLT gives further evidence of these syndromes being allelic. The relatively small size of the WASP gene facilitates the detection of mutations and a reliable diagnosis of both carriers and affected fetuses in families with WAS or XLT.

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Anti-Myelin Oligodendrocyte Glycoprotein Encephalomyelitis and Extensive Longitudinal Transverse Myelitis Associated with Compound Heterozygous NLRP3 Missense Mutations in a Young Child

Journal of Pediatric Neurology ◽

10.1055/s-0040-1721434 ◽

2020 ◽

Author(s):

Deirdre O'Sullivan ◽

Michael Moore ◽

Susan Byrne ◽

Andreas O. Reiff ◽

Susanna Felsenstein

Keyword(s):

Young Child ◽

Genetic Basis ◽

Transverse Myelitis ◽

Acute Disseminated Encephalomyelitis ◽

Myelin Oligodendrocyte Glycoprotein ◽

Compound Heterozygous ◽

Missense Mutations ◽

Childhood Onset

AbstractAcute disseminated encephalomyelitis in association with extensive longitudinal transverse myelitis is reported in a young child with positive anti-myelin oligodendrocyte glycoprotein (MOG) antibody with heterozygous NLRP3 missense mutations; p.(Arg488Lys) and p.(Ser159Ile). This case may well present an exceptional coincidence, but may describe a yet unrecognized feature of the spectrum of childhood onset cryopyrinopathies that contribute to the understanding of the genetic basis for anti-MOG antibody positive encephalomyelitis. Based on this observation, a larger scale study investigating the role of NLRP3 and other inflammasomes in this entity would provide important pathophysiological insights and potentially novel avenues for treatment.

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Recessive osteogenesis imperfecta caused by missense mutations in SPARC

Bone Abstracts ◽

10.1530/boneabs.4.lb2 ◽

2015 ◽

Author(s):

Roberto Mendoza ◽

Somayyeh Fahiminiya ◽

Jacek Majewski ◽

Martine Tetreault ◽

Javad Nadaf ◽

...

Keyword(s):

Osteogenesis Imperfecta ◽

Missense Mutations

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Identification of new ARMC5 missense mutations in Primary Bilateral Macronodular Adrenal Hyperplasia (PBMAH) and their functional studies in vitro

Endocrine Abstracts ◽

10.1530/endoabs.56.gp36 ◽

2018 ◽

Author(s):

Anna Vaczlavik ◽

Stephanie Espiard ◽

Marie-Odile North ◽

Ludivine Drougat ◽

Marthe Rizk-Rabin ◽

...

Keyword(s):

Missense Mutations ◽

Adrenal Hyperplasia ◽

Functional Studies

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Characteristics of BCR/ABL1 kinase domain mutations in the patients with chronic myeloid leukemia who are primary resistant to the imatinib therapy

Biolohichni systemy ◽

10.31861/biosystems2019.01.027 ◽

2019 ◽

Vol 11 (1) ◽

pp. 27-33

Author(s):

I Dmytrenko ◽

J Minchenko ◽

I Dyagil

Keyword(s):

Overall Survival ◽

Chronic Myeloid Leukemia ◽

Tyrosine Kinase ◽

Myeloid Leukemia ◽

High Efficiency ◽

Kinase Domain ◽

Imatinib Therapy ◽

Missense Mutations ◽

Primary Resistance ◽

Kinase Domain Mutations

The chronic myeloid leukemia (CML) development is associated with the formation of the BCR/ABL1 fusion gene and the BCR/ABL1 protein with increased tyrosine kinase activity. Despite the high efficiency of targeted therapy, up to 30% of patients do not respond on such therapy i.e. are primary resistant. The presence of BCR/ABL1 kinase domain mutations is considered to be one of the reasons of tyrosin kinase inhibitors resistance. To evaluate the frequency of BCR/ABL1 kinase domain mutations in Ukrainian cohort of CML patients with primary resistance to imatinib therapy, we retrospectively studied BCR/ABL1 kinase domain mutations in peripheral blood of 107 CML patients. The nucleotide sequence was determined by direct sequencing by Sanger. Mutations were reported in 45 of 107 (41.7%) CML patients. Two mutations at a time were revealed in 8 patients. So a total of 53 mutations were found out. Among them 49 were missense-mutations and 4 - deletions of different regions of the BCR/ABL1 kinase domain gene. The missense-mutations F359I/V (12 patients), T315I (8 patients) and G250E (6 patients) were most common. By localization, the mutations majority (23 of 53) was in the P-loop, 10 mutations - in the contact site, 13 mutations - in the catalytic domain and 6 – in the A-loop. Of the detected mutations, 26 (49%) resulted in a disruption of the hydrogen bond between BCR/ABL1-tyrosine kinase and imatinib. Significant reduction in overall survival was found in patients with BCR/ABL1 kinase domain mutations compared with patients with wild-type of BCR/ABL1 gene (p=0.018). The estimated 3-year overall survival was 83.4% (95% CI: 77.0%-89.8%) and 94.3% (95% CI: 91.0%-97.3%), respectively. Therefore, mutations of the BCR/ABL1 kinase domain are one of the mechanisms of primary resistance in CML patients on imatinib therapy. The occurrence of BCR/ABL1 gene mutations impairs the prognosis of imatinib therapy response.

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