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Your search keyword '"Massoud, Ahmed F."' showing total 4 results
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4 results on '"Massoud, Ahmed F."'

1. Functional consequence of a novel Y129C mutation in a patient with two contradictory melanocortin-2-receptor mutations.

Author

Chan LF, Chung TT, Massoud AF, Metherell LA, and Clark AJ

Subjects
Adrenocorticotropic Hormone physiology, Alleles, Animals, Blotting, Western, CHO Cells, Cell Line, Cricetinae, Cricetulus, DNA Mutational Analysis, Humans, Immunoprecipitation, Infant, Newborn, Microscopy, Confocal, Protein Folding, Receptors, Cell Surface metabolism, Mutation genetics, Mutation physiology, Receptor, Melanocortin, Type 2 genetics, Receptors, Glucocorticoid deficiency
Abstract

Context: Familial glucocorticoid deficiency (FGD) is a rare autosomal recessive disease, characterised by isolated glucocorticoid deficiency in the absence of mineralocorticoid deficiency. Inactivating mutations in the ACTH receptor (melanocortin-2-receptor, MC2R) are well described and account for approximately 25% of cases. By contrast, activating MC2R mutations are extremely rare., Patient: We report a child of Saudi Arabian origin who was diagnosed with FGD following hypoglycaemic episodes that resulted in spastic quadriplegia., Methods and Results: MC2R gene analysis revealed an unusual combination of two homozygous missense mutations, consisting of the novel mutation Y129C and the previously described F278C activating mutation. Parents were heterozygous at both of these sites. In vitro analysis of the Y129C mutation using a fluorescent cell surface assay showed that this mutant was unable to reach the cell surface in CHO cells stably transfected with MC2R accessory protein (MRAP), despite the demonstration of an interaction with MRAP by co-immunoprecipitation. The double mutant Y129C-F278C also failed to traffic to the cell surface., Conclusion: The tyrosine residue at position 129 in the second intracellular loop is critical in MC2R folding and/or trafficking to the cell surface. Furthermore, the absence of cell surface expression of MC2R would account for the lack of activation of the receptor due to the F278C mutation located at the C-terminal tail. We provide a novel molecular explanation for a child with two opposing mutations causing severe FGD.

Published
2009
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2. Comprehensive Screening of Eight Known Causative Genes in Congenital Hypothyroidism With Gland-in-Situ

Author

Nicholas, Adeline K, Serra, Eva G, Cangul, Hakan, Alyaarubi, Saif, Ullah, Irfan, Schoenmakers, Erik, Deeb, Asma, Habeb, Abdelhadi M, Almaghamsi, Mohammad, Peters, Catherine, Nathwani, Nisha, Aycan, Zehra, Saglam, Halil, Bober, Ece, Dattani, Mehul, Shenoy, Savitha, Murray, Philip G, Babiker, Amir, Willemsen, Ruben, Thankamony, Ajay, Lyons, Greta, Irwin, Rachael, Padidela, Raja, Tharian, Kavitha, Davies, Justin H, Puthi, Vijith, Park, Soo-Mi, Massoud, Ahmed F, Gregory, John W, Albanese, Assunta, Pease-Gevers, Evelien, Martin, Howard, Brugger, Kim, Maher, Eamonn R, Chatterjee, V Krishna K, Anderson, Carl A, Schoenmakers, Nadia, Schoenmakers, Erik [0000-0003-0674-8282], Maher, Eamonn [0000-0002-6226-6918], Chatterjee, Krishna [0000-0002-2654-8854], Schoenmakers, Nadia [0000-0002-0847-2884], and Apollo - University of Cambridge Repository

Subjects
Congenital Hypothyroidism/genetics, endocrine system, Genetic Screening, Iron-Binding Proteins/genetics, Receptors, Thyrotropin/genetics, Receptors, Thyrotropin, Original Articles, Autoantigens/genetics, Gene, R1, Iodide Peroxidase/genetics, Autoantigens, Iodide Peroxidase, Thyroglobulin, Pedigree, Phenotype, Thyroglobulin/genetics, Iron-Binding Proteins, Mutation, Congenital Hypothyroidism, Humans
Abstract

Context: Lower TSH screening cutoffs have doubled the ascertainment of congenital hypothyroidism (CH), particularly cases with a eutopically located gland-in-situ (GIS). Although mutations in known dyshormonogenesis genes or TSHR underlie some cases of CH with GIS, systematic screening of these eight genes has not previously been undertaken. Objective: Our objective was to evaluate the contribution and molecular spectrum of mutations in eight known causative genes (TG, TPO, DUOX2, DUOXA2, SLC5A5, SLC26A4, IYD, and TSHR) in CH cases with GIS. Patients, Design, and Setting: We screened 49 CH cases with GIS from 34 ethnically diverse families, using next-generation sequencing. Pathogenicity of novel mutations was assessed in silico. Results: Twenty-nine cases harbored likely disease-causing mutations. Monogenic defects (19 cases) most commonly involved TG (12), TPO (four), DUOX2 (two), and TSHR (one). Ten cases harbored triallelic (digenic) mutations: TG and TPO (one); SLC26A4 and TPO (three), and DUOX2 and TG (six cases). Novel variants overall included 15 TG, six TPO, and three DUOX2 mutations. Genetic basis was not ascertained in 20 patients, including 14 familial cases. Conclusions: The etiology of CH with GIS remains elusive, with only 59% attributable to mutations in TSHR or known dyshormonogenesis-associated genes in a cohort enriched for familial cases. Biallelic TG or TPO mutations most commonly underlie severe CH. Triallelic defects are frequent, mandating future segregation studies in larger kindreds to assess their contribution to variable phenotype. A high proportion (∼41%) of unsolved or ambiguous cases suggests novel genetic etiologies that remain to be elucidated., TG, TPO, DUOX2, DUOXA2, SLC5A5, SLC26A4, IYD and TSHR genes were screened in 49 cases of congenital hypothyroidism with eutopic gland-in-situ. 59% were solved including cases with triallelic mutations.

Published
2016
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3. Comprehensive screening of eight known causative genes in congenital hypothyroidism with gland-in-situ

Author

Nicholas, Adeline K., Serra, Eva G., Cangül, Hakan, Alyaarubi, Saif, Ullah, Irfan, Schoenmakers, Erik, Deeb, Asma, Habeb, Abdelhadi M., Almaghamsi, Mohammad, Peters, Catherine, Nathwani, Nisha, Aycan, Zehra, Bober, Ece, Dattani, Mehul, Shenoy, Savitha, Murray, Philip G., Babiker, Amir, Willemsen, Ruben, Thankamony, Ajay, Lyons, Greta, Irwin, Rachael, Padidela, Raja, Tharian, Kavitha, Davies, Justin H., Puthi, Vijith, Park, Soo-Mi, Massoud, Ahmed F., Gregory, John W., Albanese, Assunta, Pease-Gevers, Evelien, Martin, Howard, Brugger, Kim, Maher, Eamonn R., Chatterjee, V. Krishna K., Anderson, Carl A., Schoenmakers, Nadia, Uludağ Üniversitesi/Tıp Fakültesi/Çocuk Sağlığı ve Hastalıkları Anabilim Dalı., Sağlam, Halil, and C-7392-2019

Subjects
TPO protein, TG gene, Iodide peroxidase, Dual Oxidases, Congenital Hypothyroidism, Oxidoreductases, IYD gene, Autoantigens, Gene, Receptor gene, Thyroglobulin gene, Computer model, Phenomics, DUOX2 gene, Endocrinology & metabolism, Priority journal, Allele, Iodide organification defects, Goiter, Sequence analysis, TSHR gene, Pedigree, Phenotype, Iron-binding proteins, Cohort analysis, Human, TPO gene, Clinical article, Population, DNA sequence, Thyrotropin receptor, Guidelines, Thyroglobulin, Article, Autoantigen, Next generation sequencing, Genetic screening, Genetics, Humans, Pathogenicity, Genetic variation, Iron binding protein, Gene mutation, Receptors, thyrotropin, SLC5A5 gene, Congenital hypothyroidism, Japanese patients, DUOX2 mutations, Mutation, Genetic association, SLC26A4 gene, DUOXA2 gene, Dyshormonogenesis
Abstract

Context: Lower TSH screening cutoffs have doubled the ascertainment of congenital hypothyroidism (CH), particularly cases with a eutopically located gland-in-situ (GIS). Although mutations in known dyshormonogenesis genes or TSHR underlie some cases of CH with GIS, systematic screening of these eight genes has not previously been undertaken. Objective: Our objective was to evaluate the contribution and molecular spectrum of mutations in eight known causative genes (TG, TPO, DUOX2, DUOXA2, SLC5A5, SLC26A4, IYD, and TSHR) in CH cases with GIS. Patients, Design, and Setting:We screened 49 CH cases with GIS from 34 ethnically diverse families, using next-generation sequencing. Pathogenicity of novel mutations was assessed in silica. Results: Twenty-nine cases harbored likely disease-causing mutations. Monogenic defects (19 cases) most commonly involved TG (12), TPO (four), DUOX2 (two), and TSHR (one). Ten cases harbored triallelic (digenic) mutations: TG and TPO (one); SLC26A4 and TPO (three), and DUOX2 and TG (six cases). Novel variants overall included 15 TG, six TPO, and three DUOX2 mutations. Genetic basis was not ascertained in 20 patients, including 14 familial cases. Conclusions: The etiology of CH with GIS remains elusive, with only 59% attributable to mutations in TSHR or known dyshormonogenesis-associated genes in a cohort enriched for familial cases. Biallelic TG or TPO mutations most commonly underlie severe CH. Triallelic defects are frequent, mandating future segregation studies in larger kindreds to assess their contribution to variable phenotype. A high proportion (-41%) of unsolved or ambiguous cases suggests novel genetic etiologies that remain to be elucidated. Wellcome Trust European Commission - 100585/Z/12/Z - 095564/Z/11/Z - 098051 - WT091310 UK Research & Innovation (UKRI) Medical Research Council UK (MRC) - MC_UU_12012/5/B European Commission National Institute for Health Research (NIHR) - (NF-SI-0514-10176) NIHR (CL-2012-06-005)

Published
2016

4. Comprehensive Screening of Eight Known Causative Genes in Congenital Hypothyroidism With Gland-in-Situ

Author

Nicholas, Adeline K, Serra, Eva G, Cangul, Hakan, Alyaarubi, Saif, Ullah, Irfan, Schoenmakers, Erik, Deeb, Asma, Habeb, Abdelhadi M, Almaghamsi, Mohammad, Peters, Catherine, Nathwani, Nisha, Aycan, Zehra, Saglam, Halil, Bober, Ece, Dattani, Mehul, Shenoy, Savitha, Murray, Philip G, Babiker, Amir, Willemsen, Ruben, Thankamony, Ajay, Lyons, Greta, Irwin, Rachael, Padidela, Raja, Tharian, Kavitha, Davies, Justin H, Puthi, Vijith, Park, Soo-Mi, Massoud, Ahmed F, Gregory, John W, Albanese, Assunta, Pease-Gevers, Evelien, Martin, Howard, Brugger, Kim, Maher, Eamonn R, Chatterjee, V Krishna K, Anderson, Carl A, and Schoenmakers, Nadia

Subjects
Phenotype, Iron-Binding Proteins, Mutation, Congenital Hypothyroidism, Humans, Receptors, Thyrotropin, Autoantigens, Iodide Peroxidase, Thyroglobulin, 3. Good health, Pedigree
Abstract

CONTEXT: Lower TSH screening cutoffs have doubled the ascertainment of congenital hypothyroidism (CH), particularly cases with a eutopically located gland-in-situ (GIS). Although mutations in known dyshormonogenesis genes or TSHR underlie some cases of CH with GIS, systematic screening of these eight genes has not previously been undertaken. OBJECTIVE: Our objective was to evaluate the contribution and molecular spectrum of mutations in eight known causative genes (TG, TPO, DUOX2, DUOXA2, SLC5A5, SLC26A4, IYD, and TSHR) in CH cases with GIS. Patients, Design, and Setting: We screened 49 CH cases with GIS from 34 ethnically diverse families, using next-generation sequencing. Pathogenicity of novel mutations was assessed in silico. PATIENTS, DESIGN, AND SETTING: We screened 49 CH cases with GIS from 34 ethnically diverse families, using next-generation sequencing. Pathogenicity of novel mutations was assessed in silico. RESULTS: Twenty-nine cases harbored likely disease-causing mutations. Monogenic defects (19 cases) most commonly involved TG (12), TPO (four), DUOX2 (two), and TSHR (one). Ten cases harbored triallelic (digenic) mutations: TG and TPO (one); SLC26A4 and TPO (three), and DUOX2 and TG (six cases). Novel variants overall included 15 TG, six TPO, and three DUOX2 mutations. Genetic basis was not ascertained in 20 patients, including 14 familial cases. CONCLUSIONS: The etiology of CH with GIS remains elusive, with only 59% attributable to mutations in TSHR or known dyshormonogenesis-associated genes in a cohort enriched for familial cases. Biallelic TG or TPO mutations most commonly underlie severe CH. Triallelic defects are frequent, mandating future segregation studies in larger kindreds to assess their contribution to variable phenotype. A high proportion (∼41%) of unsolved or ambiguous cases suggests novel genetic etiologies that remain to be elucidated.

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