@article {786, title = {Further delineation of the clinical spectrum of KAT6B disorders and allelic series of pathogenic variants.}, journal = {Genet Med}, volume = {22}, year = {2020}, month = {2020 08}, pages = {1338-1347}, abstract = {

PURPOSE: Genitopatellar syndrome and Say-Barber-Biesecker-Young-Simpson syndrome are caused by variants in the KAT6B gene and are part of a broad clinical spectrum called KAT6B disorders, whose variable expressivity is increasingly being recognized.

METHODS: We herein present the phenotypes of 32 previously unreported individuals with a molecularly confirmed diagnosis of a KAT6B disorder, report 24 new pathogenic KAT6B variants, and review phenotypic information available on all published individuals with this condition. We also suggest a classification of clinical subtypes within the KAT6B disorder spectrum.

RESULTS: We demonstrate that cerebral anomalies, optic nerve hypoplasia, neurobehavioral difficulties, and distal limb anomalies other than long thumbs and great toes, such as polydactyly, are more frequently observed than initially reported. Intestinal malrotation and its serious consequences can be present in affected individuals. Additionally, we identified four children with Pierre Robin sequence, four individuals who had increased nuchal translucency/cystic hygroma prenatally, and two fetuses with severe renal anomalies leading to renal failure. We also report an individual in which a pathogenic variant was inherited from a mildly affected parent.

CONCLUSION: Our work provides a comprehensive review and expansion of the genotypic and phenotypic spectrum of KAT6B disorders that will assist clinicians in the assessment, counseling, and management of affected individuals.

}, keywords = {Blepharophimosis, Exons, Histone Acetyltransferases, Humans, Intellectual Disability, Mutation}, issn = {1530-0366}, doi = {10.1038/s41436-020-0811-8}, author = {Zhang, Li Xin and Lemire, Gabrielle and Gonzaga-Jauregui, Claudia and Molidperee, Sirinart and Galaz-Montoya, Carolina and Liu, David S and Verloes, Alain and Shillington, Amelle G and Izumi, Kosuke and Ritter, Alyssa L and Keena, Beth and Zackai, Elaine and Li, Dong and Bhoj, Elizabeth and Tarpinian, Jennifer M and Bedoukian, Emma and Kukolich, Mary K and Innes, A Micheil and Ediae, Grace U and Sawyer, Sarah L and Nair, Karippoth Mohandas and Soumya, Para Chottil and Subbaraman, Kinattinkara R and Probst, Frank J and Bassetti, Jennifer A and Sutton, Reid V and Gibbs, Richard A and Brown, Chester and Boone, Philip M and Holm, Ingrid A and Tartaglia, Marco and Ferrero, Giovanni Battista and Niceta, Marcello and Dentici, Maria Lisa and Radio, Francesca Clementina and Keren, Boris and Wells, Constance F and Coubes, Christine and Laquerri{\`e}re, Annie and Aziza, Jacqueline and Dubucs, Charlotte and Nampoothiri, Sheela and Mowat, David and Patel, Millan S and Bracho, Ana and Cammarata-Scalisi, Francisco and Gezdirici, Alper and Fern{\'a}ndez-Ja{\'e}n, Alberto and Hauser, Natalie and Zarate, Yuri A and Bosanko, Katherine A and Dieterich, Klaus and Carey, John C and Chong, Jessica X and Nickerson, Deborah A and Bamshad, Michael J and Lee, Brendan H and Yang, Xiang-Jiao and Lupski, James R and Campeau, Philippe M} } @article {814, title = {Mutations in MYLPF Cause a Novel Segmental Amyoplasia that Manifests as Distal Arthrogryposis.}, journal = {Am J Hum Genet}, volume = {107}, year = {2020}, month = {2020 08 06}, pages = {293-310}, abstract = {

We identified ten persons in six consanguineous families with distal arthrogryposis (DA) who had congenital contractures, scoliosis, and short stature. Exome sequencing revealed that each affected person was homozygous for one of two different rare variants (c.470G>T [p.Cys157Phe] or c.469T>C [p.Cys157Arg]) affecting the same residue of myosin light chain, phosphorylatable, fast skeletal muscle (MYLPF). In a seventh family, a c.487G>A (p.Gly163Ser) variant in MYLPF arose de novo in a father, who transmitted it to his son. In an eighth family comprised of seven individuals with dominantly inherited DA, a c.98C>T (p.Ala33Val) variant segregated in all four persons tested. Variants in MYLPF underlie both dominant and recessively inherited DA. Mylpf protein models suggest that the residues associated with dominant DA interact with myosin whereas the residues altered in families with recessive DA only indirectly impair this interaction. Pathological and histological exam of a foot amputated from an affected child revealed complete absence of skeletal muscle (i.e., segmental amyoplasia). To investigate the mechanism for this finding, we generated an animal model for partial MYLPF impairment by knocking out zebrafish mylpfa. The mylpfa mutant had reduced trunk contractile force and complete pectoral fin paralysis, demonstrating that mylpf impairment most severely affects limb movement. mylpfa mutant muscle weakness was most pronounced in an appendicular muscle and was explained by reduced myosin activity and fiber degeneration. Collectively, our findings demonstrate that partial loss of MYLPF function can lead to congenital contractures, likely as a result of degeneration of skeletal muscle in the distal limb.

}, keywords = {Adolescent, Amino Acid Sequence, Animals, Arthrogryposis, Child, Contracture, Extremities, Female, Humans, Male, Muscle, Skeletal, Musculoskeletal Abnormalities, Mutation, Myosin Light Chains, Myosins, Pedigree, Young Adult, Zebrafish}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2020.06.014}, author = {Chong, Jessica X and Talbot, Jared C and Teets, Emily M and Previs, Samantha and Martin, Brit L and Shively, Kathryn M and Marvin, Colby T and Aylsworth, Arthur S and Saadeh-Haddad, Reem and Schatz, Ulrich A and Inzana, Francesca and Ben-Omran, Tawfeg and Almusafri, Fatima and Al-Mulla, Mariam and Buckingham, Kati J and Harel, Tamar and Mor-Shaked, Hagar and Radhakrishnan, Periyasamy and Girisha, Katta M and Nayak, Shalini S and Shukla, Anju and Dieterich, Klaus and Faure, Julien and Rendu, John and Capri, Yline and Latypova, X{\'e}nia and Nickerson, Deborah A and Warshaw, David M and Janssen, Paul M L and Amacher, Sharon L and Bamshad, Michael J} } @article {431, title = {Genetic analysis of CHARGE syndrome identifies overlapping molecular biology.}, journal = {Genet Med}, volume = {20}, year = {2018}, month = {2018 09}, pages = {1022-1029}, abstract = {

PURPOSE: CHARGE syndrome is an autosomal-dominant, multiple congenital anomaly condition characterized by vision and hearing loss, congenital heart disease, and malformations of craniofacial and other structures. Pathogenic variants in CHD7, encoding adenosine triphosphate-dependent chromodomain helicase DNA binding protein 7, are present in the majority of affected individuals. However, no causal variant can be found in 5-30\% (depending on the cohort) of individuals with a clinical diagnosis of CHARGE syndrome.

METHODS: We performed whole-exome sequencing (WES) on 28 families from which at least one individual presented with features highly suggestive of CHARGE syndrome.

RESULTS: Pathogenic variants in CHD7 were present in 15 of 28 individuals (53.6\%), whereas 4 (14.3\%) individuals had pathogenic variants in other genes (RERE, KMT2D, EP300, or PUF60). A variant of uncertain clinical significance in KDM6A was identified in one (3.5\%) individual. The remaining eight (28.6\%) individuals were not found to have pathogenic variants by WES.

CONCLUSION: These results demonstrate that the phenotypic features of CHARGE syndrome overlap with multiple other rare single-gene syndromes. Additionally, they implicate a shared molecular pathology that disrupts epigenetic regulation of multiple-organ development.

}, keywords = {Adolescent, Adult, Carrier Proteins, CHARGE Syndrome, Child, Child, Preschool, Cohort Studies, DNA Helicases, DNA-Binding Proteins, E1A-Associated p300 Protein, Epigenesis, Genetic, Female, Genetic Testing, Humans, Infant, Male, Mutation, Neoplasm Proteins, Phenotype, Repressor Proteins, RNA Splicing Factors}, issn = {1530-0366}, doi = {10.1038/gim.2017.233}, author = {Moccia, Amanda and Srivastava, Anshika and Skidmore, Jennifer M and Bernat, John A and Wheeler, Marsha and Chong, Jessica X and Nickerson, Deborah and Bamshad, Michael and Hefner, Margaret A and Martin, Donna M and Bielas, Stephanie L} } @article {474, title = {Mutations in the Epithelial Cadherin-p120-Catenin Complex Cause Mendelian Non-Syndromic Cleft Lip with or without Cleft Palate.}, journal = {Am J Hum Genet}, volume = {102}, year = {2018}, month = {2018 06 07}, pages = {1143-1157}, abstract = {

Non-syndromic cleft lip with or without cleft palate (NS-CL/P) is one of the most common human birth defects and is generally considered a complex trait. Despite numerous loci identified by genome-wide association studies, the effect sizes of common variants are relatively small, with much of the presumed genetic contribution remaining elusive. We report exome-sequencing results in 209 people from 72 multi-affected families with pedigree structures consistent with autosomal-dominant inheritance and variable penetrance. Herein, pathogenic variants are described in four genes encoding components of the p120-catenin complex (CTNND1, PLEKHA7, PLEKHA5) and an epithelial splicing regulator (ESRP2), in addition to the known CL/P-associated gene, CDH1, which encodes E-cadherin. The findings were also validated in a second cohort of 497 people with NS-CL/P, comprising small families and singletons with pathogenic variants in these genes identified in 14\% of multi-affected families and 2\% of the replication cohort of smaller families. Enriched expression of each gene/protein in human and mouse embryonic oro-palatal epithelia, demonstration of functional impact of CTNND1 and ESRP2 variants, and recapitulation of the CL/P spectrum in Ctnnd1 knockout mice support a causative role in CL/P pathogenesis. These data show that primary defects in regulators of epithelial cell adhesion are the most significant contributors to NS-CL/P identified to date and that inherited and de novo single gene variants explain a substantial proportion of NS-CL/P.

}, keywords = {Alleles, Amino Acid Sequence, Animals, Biotinylation, Cadherins, Catenins, Cleft Lip, Cleft Palate, Epithelium, Female, Gene Deletion, Genetic Predisposition to Disease, Humans, Infant, Infant, Newborn, Male, Mice, Mutation, Palate, Pedigree, Syndrome, Whole Exome Sequencing}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2018.04.009}, author = {Cox, Liza L and Cox, Timothy C and Moreno Uribe, Lina M and Zhu, Ying and Richter, Chika T and Nidey, Nichole and Standley, Jennifer M and Deng, Mei and Blue, Elizabeth and Chong, Jessica X and Yang, Yueqin and Carstens, Russ P and Anand, Deepti and Lachke, Salil A and Smith, Joshua D and Dorschner, Michael O and Bedell, Bruce and Kirk, Edwin and Hing, Anne V and Venselaar, Hanka and Valencia-Ramirez, Luz C and Bamshad, Michael J and Glass, Ian A and Cooper, Jonathan A and Haan, Eric and Nickerson, Deborah A and van Bokhoven, Hans and Zhou, Huiqing and Krahn, Katy N and Buckley, Michael F and Murray, Jeffrey C and Lidral, Andrew C and Roscioli, Tony} } @article {412, title = {DUOX2 Gene Mutation Manifesting as Resistance to Thyrotropin Phenotype.}, journal = {Thyroid}, volume = {27}, year = {2017}, month = {2017 01}, pages = {129-131}, abstract = {

Resistance to thyrotropin (TSH) (RTSH; defined by elevated TSH and a normal or hypoplastic thyroid gland) can be caused by mutations in genes encoding the TSH receptor and PAX8, and it has been linked to a locus on chromosome 15. In two nonconsanguineous families with nongoitrous euthyroid hyperthyrotropinemia, typical of the RTSH phenotype, exome analysis identified five rare DUOX2 gene variants (p.A649E, p.P1391A, p.R885L, p.G488R, and p.SF965-6SfsX29) found to be pathogenic. This form of nongoitrous dyshormonogenesis masquerades both clinically and biochemically as RTSH. Accordingly, mutations in DUOX2 should be added to those of SLC26A4 as causes of RTSH.

}, keywords = {Child, Preschool, Congenital Hypothyroidism, Dual Oxidases, Female, Genotype, Humans, Male, Mutation, Pedigree, Phenotype, Thyroid Hormone Resistance Syndrome, Thyrotropin}, issn = {1557-9077}, doi = {10.1089/thy.2016.0469}, author = {Srichomkwun, Panudda and Takamatsu, Junta and Nickerson, Deborah A and Bamshad, Michael J and Chong, Jessica X and Refetoff, Samuel} } @article {349, title = {A postnatal role for embryonic myosin revealed by MYH3 mutations that alter TGFβ signaling and cause autosomal dominant spondylocarpotarsal synostosis.}, journal = {Sci Rep}, volume = {7}, year = {2017}, month = {2017 02 16}, pages = {41803}, abstract = {

Spondylocarpotarsal synostosis (SCT) is a skeletal disorder characterized by progressive vertebral, carpal and tarsal fusions, and mild short stature. The majority of affected individuals have an autosomal recessive form of SCT and are homozygous or compound heterozygous for nonsense mutations in the gene that encodes the cytoskeletal protein filamin B (FLNB), but a subset do not have FLNB mutations. Exome sequence analysis of three SCT patients negative for FLNB mutations identified an autosomal dominant form of the disease due to heterozygosity for missense or nonsense mutations in MYH3, which encodes embryonic myosin. Cells transfected with the MYH3 missense mutations had reduced TGFβ signaling, revealing a regulatory role for embryonic myosin in the TGFβ signaling pathway. In wild-type mice, there was persistent postnatal expression of embryonic myosin in the small muscles joining the neural arches of the spine suggesting that loss of myosin function in these muscles contribute to the disease. Our findings demonstrate that dominant mutations in MYH3 underlie autosomal dominant SCT, identify a postnatal role for embryonic myosin and suggest that altered regulation of signal transduction in the muscles within the spine may lead to the development of vertebral fusions.

}, keywords = {Abnormalities, Multiple, Alleles, Bone Morphogenetic Proteins, Cytoskeletal Proteins, Female, Genes, Dominant, Genotype, Humans, Lumbar Vertebrae, Male, Musculoskeletal Diseases, Mutation, Myosins, Phenotype, Radiography, Scoliosis, Signal Transduction, Synostosis, Thoracic Vertebrae, Transforming Growth Factor beta, Whole Exome Sequencing}, issn = {2045-2322}, doi = {10.1038/srep41803}, author = {Zieba, Jennifer and Zhang, Wenjuan and Chong, Jessica X and Forlenza, Kimberly N and Martin, Jorge H and Heard, Kelly and Grange, Dorothy K and Butler, Merlin G and Kleefstra, Tjitske and Lachman, Ralph S and Nickerson, Deborah and Regnier, Michael and Cohn, Daniel H and Bamshad, Michael and Krakow, Deborah} } @article {378, title = {Survival beyond the perinatal period expands the phenotypes caused by mutations in GLE1.}, journal = {Am J Med Genet A}, volume = {173}, year = {2017}, month = {2017 Nov}, pages = {3098-3103}, abstract = {

Mutations in GLE1 underlie Lethal Congenital Contracture syndrome (LCCS) and Lethal Arthrogryposis with Anterior Horn Cell Disease (LAAHD). Both LCCS and LAAHD are characterized by reduced fetal movements, congenital contractures, and a severe form of motor neuron disease that results in fetal death or death in the perinatal period, respectively. We identified bi-allelic mutations in GLE1 in two unrelated individuals with motor delays, feeding difficulties, and respiratory insufficiency who survived beyond the perinatal period. Each affected child had missense variants predicted to result in amino acid substitutions near the C-terminus of GLE1 that are predicted to disrupt protein-protein interaction or GLE1 protein targeting. We hypothesize that mutations that preserve function of the coiled-coil domain of GLE1 cause LAAHD whereas mutations that abolish the function of the coiled-coil domain cause LCCS. The phenotype of LAAHD is now expanded to include multiple individuals surviving into childhood suggesting that LAAHD is a misnomer and should be re-named Arthrogryposis with Anterior Horn Cell Disease (AAHD).

}, keywords = {Arthrogryposis, Child, Preschool, Female, Genetic Predisposition to Disease, Humans, Male, Motor Disorders, Motor Neuron Disease, Mutation, Nucleocytoplasmic Transport Proteins, Pedigree, Pregnancy}, issn = {1552-4833}, doi = {10.1002/ajmg.a.38406}, author = {Said, Edith and Chong, Jessica X and Hempel, Maja and Denecke, Jonas and Soler, Paul and Strom, Tim and Nickerson, Deborah A and Kubisch, Christian and Bamshad, Michael J and Lessel, Davor} } @article {70, title = {Recessive Inactivating Mutations in TBCK, Encoding a Rab GTPase-Activating Protein, Cause Severe Infantile Syndromic Encephalopathy.}, journal = {Am J Hum Genet}, volume = {98}, year = {2016}, month = {2016 Apr 07}, pages = {772-81}, abstract = {

Infantile encephalopathies are a group of clinically and biologically heterogeneous disorders for which the genetic basis remains largely unknown. Here, we report a syndromic neonatal encephalopathy characterized by profound developmental disability, severe hypotonia, seizures, diminished respiratory drive requiring mechanical ventilation, brain atrophy, dysgenesis of the corpus callosum, cerebellar vermis hypoplasia, and facial dysmorphism. Biallelic inactivating mutations in TBCK (TBC1-domain-containing kinase) were independently identified by whole-exome sequencing as the cause of this condition in four unrelated families. Matching these families was facilitated by the sharing of phenotypic profiles and WES data in a recently released web-based tool (Geno2MP) that links phenotypic information to rare variants in families with Mendelian traits. TBCK is a putative GTPase-activating protein (GAP) for small GTPases of the Rab family and has been shown to control cell growth and proliferation, actin-cytoskeleton dynamics, and mTOR signaling. Two of the three mutations (c.376C>T [p.Arg126(*)] and c.1363A>T [p.Lys455(*)]) are predicted to truncate the protein, and loss of the major TBCK isoform was confirmed in primary fibroblasts from one affected individual. The third mutation, c.1532G>A (p.Arg511His), alters a conserved residue within the TBC1 domain. Structural analysis implicated Arg511 as a required residue for Rab-GAP function, and in~silico homology modeling predicted impaired GAP function in the corresponding mutant. These results suggest that loss of Rab-GAP activity is the underlying mechanism of disease. In contrast to other disorders caused by dysregulated mTOR signaling associated with focal or global brain overgrowth, impaired TBCK function results in progressive loss of brain volume.

}, keywords = {Adolescent, Alleles, Amino Acid Sequence, Brain Diseases, Child, Child, Preschool, Corpus Callosum, Female, GTPase-Activating Proteins, Humans, Magnetic Resonance Imaging, Male, Molecular Sequence Data, Mutation, Pedigree, Protein Conformation, Protein-Serine-Threonine Kinases, Signal Transduction, TOR Serine-Threonine Kinases}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2016.01.016}, author = {Chong, Jessica X and Caputo, Viviana and Phelps, Ian G and Stella, Lorenzo and Worgan, Lisa and Dempsey, Jennifer C and Nguyen, Alina and Leuzzi, Vincenzo and Webster, Richard and Pizzuti, Antonio and Marvin, Colby T and Ishak, Gisele E and Ardern-Holmes, Simone and Richmond, Zara and Bamshad, Michael J and Ortiz-Gonzalez, Xilma R and Tartaglia, Marco and Chopra, Maya and Doherty, Dan} } @article {164, title = {Autosomal-Dominant Multiple Pterygium Syndrome Is Caused by Mutations in MYH3.}, journal = {Am J Hum Genet}, volume = {96}, year = {2015}, month = {2015 May 07}, pages = {841-9}, abstract = {

Multiple pterygium syndrome (MPS) is a phenotypically and genetically heterogeneous group of rare Mendelian conditions characterized by multiple pterygia, scoliosis, and congenital contractures of the limbs. MPS typically segregates as an autosomal-recessive disorder, but rare instances of autosomal-dominant transmission have been reported. Whereas several mutations causing recessive MPS have been identified, the genetic basis of dominant MPS remains unknown. We identified four families affected by dominantly transmitted MPS characterized by pterygia, camptodactyly of the hands, vertebral fusions, and scoliosis. Exome sequencing identified predicted protein-altering mutations in embryonic myosin heavy chain (MYH3) in three families. MYH3 mutations underlie distal arthrogryposis types 1, 2A, and 2B, but all mutations reported to date occur in the head and neck domains. In contrast, two of the mutations found to cause MPS in this study occurred in the tail domain. The phenotypic overlap among persons with MPS, coupled with physical findings distinct from other conditions caused by mutations in MYH3, suggests that the developmental mechanism underlying MPS differs from that of other conditions and/or that certain functions of embryonic myosin might be perturbed by disruption of specific residues and/or domains. Moreover, the vertebral fusions in persons with MPS, coupled with evidence of MYH3 expression in bone, suggest that embryonic myosin plays a role in skeletal development.

}, keywords = {Arthrogryposis, Cytoskeletal Proteins, Exome, Genetic Predisposition to Disease, High-Throughput Nucleotide Sequencing, Humans, Mutation, Myosins, Osteogenesis}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2015.04.004}, author = {Chong, Jessica X and Burrage, Lindsay C and Beck, Anita E and Marvin, Colby T and McMillin, Margaret J and Shively, Kathryn M and Harrell, Tanya M and Buckingham, Kati J and Bacino, Carlos A and Jain, Mahim and Alanay, Yasemin and Berry, Susan A and Carey, John C and Gibbs, Richard A and Lee, Brendan H and Krakow, Deborah and Shendure, Jay and Nickerson, Deborah A and Bamshad, Michael J} } @article {256, title = {Mutations in PIEZO2 cause Gordon syndrome, Marden-Walker syndrome, and distal arthrogryposis type 5.}, journal = {Am J Hum Genet}, volume = {94}, year = {2014}, month = {2014 May 01}, pages = {734-44}, abstract = {

Gordon syndrome (GS), or distal arthrogryposis type 3, is a rare, autosomal-dominant disorder characterized by cleft palate and congenital contractures of the hands and feet. Exome sequencing of five GS-affected families identified mutations in piezo-type mechanosensitive ion channel component 2 (PIEZO2) in each family. Sanger sequencing revealed PIEZO2 mutations in five of seven additional families studied (for a total of 10/12 [83\%] individuals), and nine families had an identical c.8057G>A (p.Arg2686His) mutation. The phenotype of GS overlaps with distal arthrogryposis type 5 (DA5) and Marden-Walker syndrome (MWS). Using molecular inversion probes for targeted sequencing to screen PIEZO2, we found mutations in 24/29 (82\%) DA5-affected families and one of two MWS-affected families. The presence of cleft palate was significantly associated with c.8057G>A (Fisher{\textquoteright}s exact test, adjusted p value < 0.0001). Collectively, although GS, DA5, and MWS have traditionally been considered separate disorders, our findings indicate that they are etiologically related and perhaps represent variable expressivity of the same condition.

}, keywords = {Abnormalities, Multiple, Arachnodactyly, Arthrogryposis, Blepharophimosis, Child, Child, Preschool, Cleft Palate, Clubfoot, Connective Tissue Diseases, Contracture, Exome, Female, Hand Deformities, Congenital, Humans, Ion Channels, Male, Mutation, Ophthalmoplegia, Pedigree, Retinal Diseases}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2014.03.015}, author = {McMillin, Margaret J and Beck, Anita E and Chong, Jessica X and Shively, Kathryn M and Buckingham, Kati J and Gildersleeve, Heidi I S and Aracena, Mariana I and Aylsworth, Arthur S and Bitoun, Pierre and Carey, John C and Clericuzio, Carol L and Crow, Yanick J and Curry, Cynthia J and Devriendt, Koenraad and Everman, David B and Fryer, Alan and Gibson, Kate and Giovannucci Uzielli, Maria Luisa and Graham, John M and Hall, Judith G and Hecht, Jacqueline T and Heidenreich, Randall A and Hurst, Jane A and Irani, Sarosh and Krapels, Ingrid P C and Leroy, Jules G and Mowat, David and Plant, Gordon T and Robertson, Stephen P and Schorry, Elizabeth K and Scott, Richard H and Seaver, Laurie H and Sherr, Elliott and Splitt, Miranda and Stewart, Helen and Stumpel, Constance and Temel, Sehime G and Weaver, David D and Whiteford, Margo and Williams, Marc S and Tabor, Holly K and Smith, Joshua D and Shendure, Jay and Nickerson, Deborah A and Bamshad, Michael J} } @article {265, title = {Solving glycosylation disorders: fundamental approaches reveal complicated pathways.}, journal = {Am J Hum Genet}, volume = {94}, year = {2014}, month = {2014 Feb 06}, pages = {161-75}, abstract = {

Over 100 human genetic disorders result from mutations in glycosylation-related genes. In 2013, a new glycosylation disorder was reported every 17 days. This trend will probably continue given that at least 2\% of the human genome encodes glycan-biosynthesis and -recognition proteins. Established biosynthetic pathways provide many candidate genes, but finding unanticipated mutated genes will offer new insights into glycosylation. Simple glycobiomarkers can be used in narrowing the candidates identified by exome and genome sequencing, and those can be validated by glycosylation analysis of serum or cells from affected individuals. Model organisms will expand the understanding of these mutations{\textquoteright} impact on glycosylation and pathology. Here, we highlight some recently discovered glycosylation disorders and the barriers, breakthroughs, and surprises they presented. We predict that some glycosylation disorders might occur with greater frequency than current estimates of their prevalence. Moreover, the prevalence of some disorders differs substantially between European and African Americans.

}, keywords = {Congenital Disorders of Glycosylation, Exome, Genome, Human, Glucose, Glycogen, Glycosylation, Homeostasis, Humans, Mannose, Mutation}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2013.10.024}, author = {Freeze, Hudson H and Chong, Jessica X and Bamshad, Michael J and Ng, Bobby G} } @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} }