@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 {381, title = {Encephalopathy caused by novel mutations in the CMP-sialic acid transporter, SLC35A1.}, journal = {Am J Med Genet A}, volume = {173}, year = {2017}, month = {2017 Nov}, pages = {2906-2911}, abstract = {

Transport of activated nucleotide-sugars into the Golgi is critical for proper glycosylation and mutations in these transporters cause a group of rare genetic disorders termed congenital disorders of glycosylation. We performed exome sequencing on an individual with a profound neurological presentation and identified rare compound heterozygous mutations, p.Thr156Arg and p.Glu196Lys, in the CMP-sialic acid transporter, SLC35A1. Patient primary fibroblasts and serum showed a considerable decrease in the amount of N- and O-glycans terminating in sialic acid. Direct measurement of CMP-sialic acid transport into the Golgi showed a substantial decrease in overall rate of transport. Here we report the identification of the third patient with CMP-sialic acid transporter deficiency, who presented with severe neurological phenotype, but without hematological abnormalities.

}, keywords = {Animals, Brain Diseases, Child, CHO Cells, Cricetinae, Cricetulus, Female, Flow Cytometry, Golgi Apparatus, Humans, Mutation, N-Acetylneuraminic Acid, Nucleotide Transport Proteins, Whole Exome Sequencing}, issn = {1552-4833}, doi = {10.1002/ajmg.a.38412}, author = {Ng, Bobby G and Asteggiano, Carla G and Kircher, Martin and Buckingham, Kati J and Raymond, Kimiyo and Nickerson, Deborah A and Shendure, Jay and Bamshad, Michael J and Ensslen, Matthias and Freeze, Hudson H} } @article {134, title = {Expanding the Molecular and Clinical Phenotype of SSR4-CDG.}, journal = {Hum Mutat}, volume = {36}, year = {2015}, month = {2015 Nov}, pages = {1048-51}, abstract = {

Congenital disorders of glycosylation (CDG) are a group of mostly autosomal recessive disorders primarily characterized by neurological abnormalities. Recently, we described a single CDG patient with a de novo mutation in the X-linked gene, Signal Sequence Receptor 4 (SSR4). We performed whole-exome sequencing to identify causal variants in several affected individuals who had either an undifferentiated neurological disorder or unsolved CDG of unknown etiology based on abnormal transferrin glycosylation. We now report eight affected males with either de novo (4) or inherited (4) loss of function mutations in SSR4. Western blot analysis revealed that the mutations caused a complete loss of SSR4 protein. In nearly all cases, the abnormal glycosylation of serum transferrin was only slightly above the accepted normal cutoff range.

}, keywords = {Calcium-Binding Proteins, Congenital Disorders of Glycosylation, DNA Mutational Analysis, Exome, Gene Order, Genes, X-Linked, Genetic Loci, Humans, Male, Membrane Glycoproteins, Mutation, Phenotype, Receptors, Cytoplasmic and Nuclear, Receptors, Peptide}, issn = {1098-1004}, doi = {10.1002/humu.22856}, author = {Ng, Bobby G and Raymond, Kimiyo and Kircher, Martin and Buckingham, Kati J and Wood, Tim and Shendure, Jay and Nickerson, Deborah A and Bamshad, Michael J and Wong, Jonathan T S and Monteiro, Fabiola Paoli and Graham, Brett H and Jackson, Sheryl and Sparkes, Rebecca and Scheuerle, Angela E and Cathey, Sara and Kok, Fernando and Gibson, James B and Freeze, Hudson H} }