@article {997, title = {Expanding the phenotype, genotype and biochemical knowledge of ALG3-CDG.}, journal = {J Inherit Metab Dis}, year = {2021}, month = {2021 Feb 13}, abstract = {

Congenital disorders of glycosylation (CDGs) are a continuously expanding group of monogenic disorders of glycoprotein and glycolipid biosynthesis that cause multisystem diseases. Individuals with ALG3-CDG frequently exhibit severe neurological involvement (epilepsy, microcephaly, and hypotonia), ocular anomalies, dysmorphic features, skeletal anomalies, and feeding difficulties. We present 10 unreported individuals diagnosed with ALG3-CDG based on molecular and biochemical testing with 11 novel variants in ALG3, bringing the total to 40 reported individuals. In addition to the typical multisystem disease seen in ALG3-CDG, we expand the symptomatology of ALG3-CDG to now include endocrine abnormalities, neural tube defects, mild aortic root dilatation, immunodeficiency, and renal anomalies. N-glycan analyses of these individuals showed combined deficiencies of hybrid glycans and glycan extension beyond Man GlcNAc consistent with their truncated lipid-linked precursor oligosaccharides. This spectrum of N-glycan changes is unique to ALG3-CDG. These expanded features of ALG3-CDG facilitate diagnosis and suggest that optimal management should include baseline endocrine, renal, cardiac, and immunological evaluation at the time of diagnosis and with ongoing monitoring.

}, issn = {1573-2665}, doi = {10.1002/jimd.12367}, author = {Alsharhan, Hind and Ng, Bobby G and Daniel, Earnest James Paul and Friedman, Jennifer and Pivnick, Eniko K and Al-Hashem, Amal and Faqeih, Eissa Ali and Liu, Pengfei and Engelhardt, Nicole M and Keller, Kierstin N and Chen, Jie and Mazzeo, Pamela A and Rosenfeld, Jill A and Bamshad, Michael J and Nickerson, Deborah A and Raymond, Kimiyo M and Freeze, Hudson H and He, Miao and Edmondson, Andrew C and Lam, Christina} } @article {77, title = {ALG1-CDG: Clinical and Molecular Characterization of 39 Unreported Patients.}, journal = {Hum Mutat}, volume = {37}, year = {2016}, month = {2016 07}, pages = {653-60}, abstract = {

Congenital disorders of glycosylation (CDG) arise from pathogenic mutations in over 100 genes leading to impaired protein or lipid glycosylation. ALG1 encodes a β1,4 mannosyltransferase that catalyzes the addition of the first of nine mannose moieties to form a dolichol-lipid linked oligosaccharide intermediate required for proper N-linked glycosylation. ALG1 mutations cause a rare autosomal recessive disorder termed ALG1-CDG. To date 13 mutations in 18 patients from 14 families have been described with varying degrees of clinical severity. We identified and characterized 39 previously unreported cases of ALG1-CDG from 32 families and add 26 new mutations. Pathogenicity of each mutation was confirmed based on its inability to rescue impaired growth or hypoglycosylation of a standard biomarker in an alg1-deficient yeast strain. Using this approach we could not establish a rank order comparison of biomarker glycosylation and patient phenotype, but we identified mutations with a lethal outcome in the first two years of life. The recently identified protein-linked xeno-tetrasaccharide biomarker, NeuAc-Gal-GlcNAc2 , was seen in all 27 patients tested. Our study triples the number of known patients and expands the molecular and clinical correlates of this disorder.

}, keywords = {Biomarkers, Congenital Disorders of Glycosylation, Female, Genes, Lethal, Glycosylation, Humans, Male, Mannosyltransferases, Mutation, Polysaccharides, Sequence Analysis, DNA, Survival Analysis}, issn = {1098-1004}, doi = {10.1002/humu.22983}, author = {Ng, Bobby G and Shiryaev, Sergey A and Rymen, Daisy and Eklund, Erik A and Raymond, Kimiyo and Kircher, Martin and Abdenur, Jose E and Alehan, Fusun and Midro, Alina T and Bamshad, Michael J and Barone, Rita and Berry, Gerard T and Brumbaugh, Jane E and Buckingham, Kati J and Clarkson, Katie and Cole, F Sessions and O{\textquoteright}Connor, Shawn and Cooper, Gregory M and Van Coster, Rudy and Demmer, Laurie A and Diogo, Luisa and Fay, Alexander J and Ficicioglu, Can and Fiumara, Agata and Gahl, William A and Ganetzky, Rebecca and Goel, Himanshu and Harshman, Lyndsay A and He, Miao and Jaeken, Jaak and James, Philip M and Katz, Daniel and Keldermans, Liesbeth and Kibaek, Maria and Kornberg, Andrew J and Lachlan, Katherine and Lam, Christina and Yaplito-Lee, Joy and Nickerson, Deborah A and Peters, Heidi L and Race, Valerie and R{\'e}gal, Luc and Rush, Jeffrey S and Rutledge, S Lane and Shendure, Jay and Souche, Erika and Sparks, Susan E and Trapane, Pamela and Sanchez-Valle, Amarilis and Vilain, Eric and V{\o}llo, Arve and Waechter, Charles J and Wang, Raymond Y and Wolfe, Lynne A and Wong, Derek A and Wood, Tim and Yang, Amy C and Matthijs, Gert and Freeze, Hudson H} } @article {305, title = {Mosaicism of the UDP-galactose transporter SLC35A2 causes a congenital disorder of glycosylation.}, journal = {Am J Hum Genet}, volume = {92}, year = {2013}, month = {2013 Apr 04}, pages = {632-6}, abstract = {

Biochemical analysis and whole-exome sequencing identified mutations in the Golgi-localized UDP-galactose transporter SLC35A2 that define an undiagnosed X-linked congenital disorder of glycosylation (CDG) in three unrelated families. Each mutation reduced UDP-galactose transport, leading to galactose-deficient glycoproteins. Two affected males were somatic mosaics, suggesting that a wild-type SLC35A2 allele may be required for survival. In infancy, the commonly used biomarker transferrin showed abnormal glycosylation, but its appearance became normal later in childhood, without any corresponding clinical improvement. This may indicate selection against cells carrying the mutant allele. To detect other individuals with such mutations, we suggest transferrin testing in infancy. Here, we report somatic mosaicism in CDG, and our work stresses the importance of combining both genetic and biochemical diagnoses.

}, keywords = {Biological Transport, Case-Control Studies, Child, Child, Preschool, Congenital Disorders of Glycosylation, Exome, Female, Glycosylation, Humans, Male, Monosaccharide Transport Proteins, Mosaicism, Mutation, Spectrometry, Mass, Electrospray Ionization, Transferrin, Uridine Diphosphate Galactose}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2013.03.012}, author = {Ng, Bobby G and Buckingham, Kati J and Raymond, Kimiyo and Kircher, Martin and Turner, Emily H and He, Miao and Smith, Joshua D and Eroshkin, Alexey and Szybowska, Marta and Losfeld, Marie E and Chong, Jessica X and Kozenko, Mariya and Li, Chumei and Patterson, Marc C and Gilbert, Rodney D and Nickerson, Deborah A and Shendure, Jay and Bamshad, Michael J and Freeze, Hudson H} }