@article {949, title = {A relatively common homozygous TRAPPC4 splicing variant is associated with an early-infantile neurodegenerative syndrome.}, journal = {Eur J Hum Genet}, volume = {29}, year = {2021}, month = {2021 Feb}, pages = {271-279}, abstract = {

Trafficking protein particle (TRAPP) complexes, which include the TRAPPC4 protein, regulate membrane trafficking between lipid organelles in a process termed vesicular tethering. TRAPPC4 was recently implicated in a recessive neurodevelopmental condition in four unrelated families due to a shared c.454+3A>G splice variant. Here, we report 23 patients from 17 independent families with an early-infantile-onset neurodegenerative presentation, where we also identified the homozygous variant hg38:11:119020256 A>G (NM_016146.5:c.454+3A>G) in TRAPPC4 through exome or genome sequencing. No other clinically relevant TRAPPC4 variants were identified among any of over 10,000 patients with neurodevelopmental conditions. We found the carrier frequency of TRAPPC4 c.454+3A>G was 2.4-5.4 per 10,000 healthy individuals. Affected individuals with the homozygous TRAPPC4 c.454+3A>G variant showed profound psychomotor delay, developmental regression, early-onset epilepsy, microcephaly and progressive spastic tetraplegia. Based upon RNA sequencing, the variant resulted in partial exon 3 skipping and generation of an aberrant transcript owing to use of a downstream cryptic splice donor site, predicting a premature stop codon and nonsense mediated decay. These data confirm the pathogenicity of the TRAPPC4 c.454+3A>G variant, and refine the clinical presentation of TRAPPC4-related encephalopathy.

}, issn = {1476-5438}, doi = {10.1038/s41431-020-00717-5}, author = {Ghosh, Shereen G and Scala, Marcello and Beetz, Christian and Helman, Guy and Stanley, Valentina and Yang, Xiaoxu and Breuss, Martin W and Mazaheri, Neda and Selim, Laila and Hadipour, Fatemeh and Pais, Lynn and Stutterd, Chloe A and Karageorgou, Vasiliki and Begtrup, Amber and Crunk, Amy and Juusola, Jane and Willaert, Rebecca and Flore, Leigh A and Kennelly, Kelly and Spencer, Christopher and Brown, Martha and Trapane, Pamela and Hurst, Anna C E and Lane Rutledge, S and Goodloe, Dana H and McDonald, Marie T and Shashi, Vandana and Schoch, Kelly and Tomoum, Hoda and Zaitoun, Raghda and Hadipour, Zahra and Galehdari, Hamid and Pagnamenta, Alistair T and Mojarrad, Majid and Sedaghat, Alireza and Dias, Patr{\'\i}cia and Quintas, Sofia and Eslahi, Atiyeh and Shariati, Gholamreza and Bauer, Peter and Simons, Cas and Houlden, Henry and Issa, Mahmoud Y and Zaki, MAH S and Maroofian, Reza and Gleeson, Joseph G} } @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 {46, title = {Congenital nephrotic syndrome in an infant with ALG1-congenital disorder of glycosylation.}, journal = {Pediatr Int}, volume = {58}, year = {2016}, month = {2016 Aug}, pages = {785-8}, abstract = {

Congenital nephrotic syndrome (NS) in the newborn is most frequently related to mutations in genes specific for structural integrity of the glomerular basement membrane and associated filtration structures within the kidney, resulting in massive leakage of plasma proteins into the urine. Occurrence of congenital NS in a multi-system syndrome is less common. We describe the case of an infant with deteriorating neurological status, seizures, edema, and proteinuria who was found to have a mutation in gene ALG1 and a renal biopsy consistent with congenital NS. Furthermore, we briefly review rare existing case reports documenting congenital NS in patients with mutations in ALG1, and treatment strategies, including novel use of peritoneal dialysis.

}, keywords = {Abnormalities, Multiple, Congenital Disorders of Glycosylation, DNA, DNA Mutational Analysis, Glycosylation, Humans, Infant, Newborn, Male, Mannosyltransferases, Mutation, Nephrotic Syndrome, Peritoneal Dialysis}, issn = {1442-200X}, doi = {10.1111/ped.12988}, author = {Harshman, Lyndsay A and Ng, Bobby G and Freeze, Hudson H and Trapane, Pamela and Dolezal, Anna and Brophy, Patrick D and Brumbaugh, Jane E} }