@article {446, title = {WNT Signaling Perturbations Underlie the Genetic Heterogeneity of Robinow Syndrome.}, journal = {Am J Hum Genet}, volume = {102}, year = {2018}, month = {2018 01 04}, pages = {27-43}, abstract = {

Locus heterogeneity characterizes a variety of skeletal dysplasias often due to interacting or overlapping signaling pathways. Robinow syndrome is a skeletal disorder historically refractory to molecular diagnosis, potentially stemming from substantial genetic heterogeneity. All current known pathogenic variants reside in genes within the noncanonical Wnt signaling pathway including ROR2, WNT5A, and more recently, DVL1 and DVL3. However, \~{}70\% of autosomal-dominant Robinow syndrome cases remain molecularly unsolved. To investigate this missing heritability, we recruited 21 families with at least one family member clinically diagnosed with Robinow or Robinow-like phenotypes and performed genetic and genomic studies. In total, four families with variants in FZD2 were identified as well as three individuals from two families with biallelic variants in NXN that co-segregate with the phenotype. Importantly, both FZD2 and NXN are relevant protein partners in the WNT5A interactome, supporting their role in skeletal development. In addition to confirming that clustered -1 frameshifting variants in DVL1 and DVL3 are the main contributors to dominant Robinow syndrome, we also found likely pathogenic variants in candidate genes GPC4 and RAC3, both linked to the Wnt signaling pathway. These data support an initial hypothesis that Robinow syndrome results from perturbation of the Wnt/PCP pathway, suggest specific relevant domains of the proteins involved, and reveal key contributors in this signaling cascade during human embryonic development. Contrary to the view that non-allelic genetic heterogeneity hampers gene discovery, this study demonstrates the utility of rare disease genomic studies to parse gene function in human developmental pathways.

}, keywords = {Adolescent, Adult, Base Sequence, Child, Child, Preschool, Chromosome Segregation, Craniofacial Abnormalities, Diagnosis, Differential, Dwarfism, Female, Genes, Dominant, Genetic Association Studies, Genetic Heterogeneity, Humans, Limb Deformities, Congenital, Male, Middle Aged, Mutation, Missense, Phenotype, Urogenital Abnormalities, Wnt Signaling Pathway}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2017.10.002}, author = {White, Janson J and Mazzeu, Juliana F and Coban-Akdemir, Zeynep and Bayram, Yavuz and Bahrambeigi, Vahid and Hoischen, Alexander and van Bon, Bregje W M and Gezdirici, Alper and Gulec, Elif Yilmaz and Ramond, Francis and Touraine, Renaud and Thevenon, Julien and Shinawi, Marwan and Beaver, Erin and Heeley, Jennifer and Hoover-Fong, Julie and Durmaz, Ceren D and Karabulut, Halil Gurhan and Marzioglu-Ozdemir, Ebru and Cayir, Atilla and Duz, Mehmet B and Seven, Mehmet and Price, Susan and Ferreira, Barbara Merfort and Vianna-Morgante, Angela M and Ellard, Sian and Parrish, Andrew and Stals, Karen and Flores-Daboub, Josue and Jhangiani, Shalini N and Gibbs, Richard A and Brunner, Han G and Sutton, V Reid and Lupski, James R and Carvalho, Claudia M B} } @article {422, title = {Mutations in Fibronectin Cause a Subtype of Spondylometaphyseal Dysplasia with "Corner Fractures".}, journal = {Am J Hum Genet}, volume = {101}, year = {2017}, month = {2017 Nov 02}, pages = {815-823}, abstract = {

Fibronectin is a master organizer of extracellular matrices (ECMs) and promotes the assembly of collagens, fibrillin-1, and other proteins. It is also known to play roles in skeletal tissues through its secretion by osteoblasts, chondrocytes, and mesenchymal cells. Spondylometaphyseal dysplasias (SMDs) comprise a diverse group of skeletal dysplasias and often manifest as short stature, growth-plate irregularities, and vertebral anomalies, such as scoliosis. By comparing the exomes of individuals with SMD with the radiographic appearance of "corner fractures" at metaphyses, we identified three individuals with fibronectin (FN1) variants affecting highly conserved residues. Furthermore, using matching tools and the SkelDys emailing list, we identified other individuals with de novo~FN1 variants and a similar phenotype. The severe scoliosis in most individuals and rare developmental coxa vara distinguish individuals with FN1 mutations from those with classical Sutcliffe-type SMD. To study functional consequences of these FN1 mutations on the protein level, we introduced three disease-associated missense variants (p.Cys87Phe [c.260G>T], p.Tyr240Asp [c.718T>G], and p.Cys260Gly [c.778T>G]) into a recombinant secreted N-terminal 70~kDa fragment (rF70K) and the full-length fibronectin (rFN). The wild-type rF70K and rFN were secreted into the culture medium, whereas all mutant proteins were either not secreted or secreted at significantly lower amounts. Immunofluorescence analysis demonstrated increased intracellular retention of the mutant proteins. In summary, FN1 mutations that cause defective fibronectin secretion are found in SMD, and we thus provide additional evidence for a critical function of fibronectin in cartilage and bone.

}, keywords = {Adolescent, Adult, Bone and Bones, Bone Diseases, Developmental, Cartilage, Child, Child, Preschool, Exome, Female, Fibronectins, Fractures, Bone, Humans, Male, Mutation, Osteochondrodysplasias, Phenotype, Scoliosis}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2017.09.019}, author = {Lee, Chae Syng and Fu, He and Baratang, Nissan and Rousseau, Justine and Kumra, Heena and Sutton, V Reid and Niceta, Marcello and Ciolfi, Andrea and Yamamoto, Guilherme and Bertola, D{\'e}bora and Marcelis, Carlo L and Lugtenberg, Dorien and Bartuli, Andrea and Kim, Choel and Hoover-Fong, Julie and Sobreira, Nara and Pauli, Richard and Bacino, Carlos and Krakow, Deborah and Parboosingh, Jillian and Yap, Patrick and Kariminejad, Ariana and McDonald, Marie T and Aracena, Mariana I and Lausch, Ekkehart and Unger, Sheila and Superti-Furga, Andrea and Lu, James T and Cohn, Dan H and Tartaglia, Marco and Lee, Brendan H and Reinhardt, Dieter P and Campeau, Philippe M} } @article {62, title = {A Syndromic Intellectual Disability Disorder Caused by Variants in TELO2, a Gene Encoding a Component of the TTT Complex.}, journal = {Am J Hum Genet}, volume = {98}, year = {2016}, month = {2016 05 05}, pages = {909-918}, abstract = {

The proteins encoded by TELO2, TTI1, and TTI2 interact to form the TTT complex, a co-chaperone for maturation of the phosphatidylinositol 3-kinase-related protein kinases (PIKKs). Here we report six affected individuals from four families with intellectual disability (ID) and neurological and other congenital abnormalities associated with compound heterozygous variants in TELO2. Although their fibroblasts showed reduced steady-state levels of TELO2 and the other components of the TTT complex, PIKK functions were normal in cellular assays. Our results suggest that these TELO2 missense variants result in loss of function, perturb TTT complex stability, and cause an autosomal-recessive syndromic form of ID.

}, keywords = {Adolescent, Carrier Proteins, Child, Female, Humans, Intellectual Disability, Male, Molecular Chaperones, Pedigree, Phosphatidylinositol 3-Kinases, Protein-Serine-Threonine Kinases, Telomere-Binding Proteins}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2016.03.014}, author = {You, Jing and Sobreira, Nara L and Gable, Dustin L and Jurgens, Julie and Grange, Dorothy K and Belnap, Newell and Siniard, Ashley and Szelinger, Szabolcs and Schrauwen, Isabelle and Richholt, Ryan F and Vallee, Stephanie E and Dinulos, Mary Beth P and Valle, David and Armanios, Mary and Hoover-Fong, Julie} } @article {641, title = {An anadysplasia-like, spontaneously remitting spondylometaphyseal dysplasia secondary to lamin B receptor (LBR) gene mutations: further definition of the phenotypic heterogeneity of LBR-bone dysplasias.}, journal = {Am J Med Genet A}, volume = {167A}, year = {2015}, month = {2015 Jan}, pages = {159-63}, abstract = {

We describe a boy who has an anadysplasia-like spondylometaphyseal dysplasia. By whole exome sequencing he was shown to have compound heterozygous mutations of LBR that codes for the lamin B receptor. He shares many similarities with a case previously described, but in whom the early natural history could not be established [Borovik et al., 2013]. Thus, in addition to Greenberg dysplasia (a perinatal lethal disorder), homozygosity or compound heterozygosity of mutations in LBR can result in a mild, spontaneously regressing bone dysplasia.

}, keywords = {Adolescent, Adult, Child, Child, Preschool, Female, Humans, Infant, Infant, Newborn, Male, Mutation, Osteochondrodysplasias, Phenotype, Pregnancy, Radiography, Receptors, Cytoplasmic and Nuclear, Spine}, issn = {1552-4833}, doi = {10.1002/ajmg.a.36808}, author = {Sobreira, Nara and Modaff, Peggy and Steel, Gary and You, Jing and Nanda, Sonia and Hoover-Fong, Julie and Valle, David and Pauli, Richard M} } @article {275, title = {Mutations in PCYT1A, encoding a key regulator of phosphatidylcholine metabolism, cause spondylometaphyseal dysplasia with cone-rod dystrophy.}, journal = {Am J Hum Genet}, volume = {94}, year = {2014}, month = {2014 Jan 02}, pages = {105-12}, keywords = {Alleles, Child, Preschool, Choline-Phosphate Cytidylyltransferase, Female, Humans, Infant, Male, Middle Aged, Mutation, Missense, Osteochondrodysplasias, Pedigree, Phosphatidylcholines, Retinitis Pigmentosa}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2013.11.018}, author = {Hoover-Fong, Julie and Sobreira, Nara and Jurgens, Julie and Modaff, Peggy and Blout, Carrie and Moser, Ann and Kim, Ok-Hwa and Cho, Tae-Joon and Cho, Sung Yoon and Kim, Sang Jin and Jin, Dong-Kyu and Kitoh, Hiroshi and Park, Woong-Yang and Ling, Hua and Hetrick, Kurt N and Doheny, Kimberly F and Valle, David and Pauli, Richard M} }