@article {593, title = {Bi-allelic Variants in TONSL Cause SPONASTRIME Dysplasia and a Spectrum of Skeletal Dysplasia Phenotypes.}, journal = {Am J Hum Genet}, volume = {104}, year = {2019}, month = {2019 03 07}, pages = {422-438}, abstract = {

SPONASTRIME dysplasia is an autosomal-recessive spondyloepimetaphyseal dysplasia characterized by spine (spondylar) abnormalities, midface hypoplasia with a depressed nasal bridge, metaphyseal striations, and disproportionate short stature. Scoliosis, coxa vara, childhood cataracts, short dental roots, and hypogammaglobulinemia have also been reported in this disorder. Although an autosomal-recessive~inheritance pattern has been hypothesized, pathogenic variants in a specific gene have not been discovered in individuals with SPONASTRIME dysplasia. Here, we identified bi-allelic variants in TONSL, which encodes the Tonsoku-like DNA repair protein, in nine subjects (from eight families) with SPONASTRIME dysplasia, and four subjects (from three families) with short stature of varied severity and spondylometaphyseal dysplasia with or without immunologic and hematologic abnormalities, but no definitive metaphyseal striations at diagnosis. The finding of early embryonic lethality in a Tonsl murine model and the discovery of reduced length, spinal abnormalities, reduced numbers of neutrophils, and early lethality in a tonsl zebrafish model both support the hypomorphic nature of the identified TONSL variants. Moreover, functional studies revealed increased amounts of spontaneous replication fork stalling and chromosomal aberrations, as well as fewer camptothecin (CPT)-induced RAD51 foci in subject-derived cell lines. Importantly, these cellular defects were rescued upon re-expression of wild-type (WT) TONSL; this rescue is consistent with the hypothesis that hypomorphic TONSL variants are pathogenic. Overall, our studies in humans, mice, zebrafish, and subject-derived cell lines confirm that pathogenic variants in TONSL impair DNA replication and homologous recombination-dependent repair processes, and they lead to a spectrum of skeletal dysplasia phenotypes with numerous extra-skeletal manifestations.

}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2019.01.007}, author = {Burrage, Lindsay C and Reynolds, John J and Baratang, Nissan Vida and Phillips, Jennifer B and Wegner, Jeremy and McFarquhar, Ashley and Higgs, Martin R and Christiansen, Audrey E and Lanza, Denise G and Seavitt, John R and Jain, Mahim and Li, Xiaohui and Parry, David A and Raman, Vandana and Chitayat, David and Chinn, Ivan K and Bertuch, Alison A and Karaviti, Lefkothea and Schlesinger, Alan E and Earl, Dawn and Bamshad, Michael and Savarirayan, Ravi and Doddapaneni, Harsha and Muzny, Donna and Jhangiani, Shalini N and Eng, Christine M and Gibbs, Richard A and Bi, Weimin and Emrick, Lisa and Rosenfeld, Jill A and Postlethwait, John and Westerfield, Monte and Dickinson, Mary E and Beaudet, Arthur L and Ranza, Emmanuelle and Huber, Celine and Cormier-Daire, Val{\'e}rie and Shen, Wei and Mao, Rong and Heaney, Jason D and Orange, Jordan S and Bertola, D{\'e}bora and Yamamoto, Guilherme L and Baratela, Wagner A R and Butler, Merlin G and Ali, Asim and Adeli, Mehdi and Cohn, Daniel H and Krakow, Deborah and Jackson, Andrew P and Lees, Melissa and Offiah, Amaka C and Carlston, Colleen M and Carey, John C and Stewart, Grant S and Bacino, Carlos A and Campeau, Philippe M and Lee, Brendan} } @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 {433, title = {Patients with a Kabuki syndrome phenotype demonstrate DNA methylation abnormalities.}, journal = {Eur J Hum Genet}, volume = {25}, year = {2017}, month = {2017 12}, pages = {1335-1344}, abstract = {

Kabuki syndrome is a monogenic disorder caused by loss of function variants in either of two genes encoding histone-modifying enzymes. We performed targeted sequencing in a cohort of 27 probands with a clinical diagnosis of Kabuki syndrome. Of these, 12 had causative variants in the two known Kabuki syndrome genes. In 2, we identified presumptive loss of function de novo variants in KMT2A (missense and splice site variants), a gene that encodes another histone modifying enzyme previously exclusively associated with Wiedermann-Steiner syndrome. Although Kabuki syndrome is a disorder of histone modification, we also find alterations in DNA methylation among individuals with a Kabuki syndrome diagnosis relative to matched normal controls, regardless of whether they carry a variant in KMT2A or KMT2D or not. Furthermore, we observed characteristic global abnormalities of DNA methylation that distinguished patients with a loss of function variant in KMT2D or missense or splice site variants in either KMT2D or KMT2A from normal controls. Our results provide new insights into the relationship of genotype to epigenotype and phenotype and indicate cross-talk between histone and DNA methylation machineries exposed by inborn errors of the epigenetic apparatus.

}, keywords = {Abnormalities, Multiple, Case-Control Studies, Child, DNA Methylation, Face, Female, Hematologic Diseases, Histone-Lysine N-Methyltransferase, Humans, Loss of Function Mutation, Male, Myeloid-Lymphoid Leukemia Protein, Phenotype, Vestibular Diseases}, issn = {1476-5438}, doi = {10.1038/s41431-017-0023-0}, author = {Sobreira, Nara and Brucato, Martha and Zhang, Li and Ladd-Acosta, Christine and Ongaco, Chrissie and Romm, Jane and Doheny, Kimberly F and Mingroni-Netto, Regina C and Bertola, D{\'e}bora and Kim, Chong A and Perez, Ana Ba and Melaragno, Maria I and Valle, David and Meloni, Vera A and Bjornsson, Hans T} }