@article {240, title = {Diamond-Blackfan anemia with mandibulofacial dystostosis is heterogeneous, including the novel DBA genes TSR2 and RPS28.}, journal = {Am J Med Genet A}, volume = {164A}, year = {2014}, month = {2014 Sep}, pages = {2240-9}, abstract = {

Patients with physical findings suggestive of Treacher Collins syndrome (TCS) or mandibulofacial dysostosis (MFD) and macrocytic anemia diagnostic of Diamond-Blackfan anemia (DBA) have been reported. Disease-causing genes have been identified for TCS and other MFDs. Mutations in several ribosomal protein genes and the transcription factor GATA1 result in DBA. However, no disease-causing mutation had been identified in the reported patients with the combination of TCS/MFD and DBA phenotype, and we hypothesized that pathogenic mutations in a single gene could be identified using whole exome analysis. We studied probands from six unrelated families. Combining exome analysis and Sanger sequencing, we identified likely pathogenic mutations in 5/6 families. Two mutations in unrelated families were seen in RPS26, the known DBA10 gene. One variant was predicted to affect mRNA splicing, and the other to lead to protein truncation. In another family a likely pathogenic X-linked mutation affecting a highly conserved residue was found in TSR2, which encodes a direct binding partner of RPS26. De novo mutations affecting the RPS28 start codon were found in two unrelated probands, identifying RPS28 as a novel disease gene. We conclude that the phenotype combining features of TCS with DBA is genetically heterogeneous. Each of the pathogenic variants identified is predicted to impede ribosome biogenesis, which in turn could result in altered cell growth and proliferation, causing abnormal embryologic development, defective erythropoiesis and reduced growth. The phenotype combining TCS/MFD and DBA is highly variable, overlaps with DBA and lies within the phenotypic spectrum of ribosomopathies. {\textcopyright} 2014 Wiley Periodicals, Inc.

}, keywords = {Adult, Anemia, Diamond-Blackfan, Apoptosis Regulatory Proteins, Child, Preschool, Exome, Family, Female, Genetic Heterogeneity, Humans, Infant, Infant, Newborn, Male, Mandibulofacial Dysostosis, Pedigree, Phenotype, Pregnancy, Ribosomal Proteins, Young Adult}, issn = {1552-4833}, doi = {10.1002/ajmg.a.36633}, author = {Gripp, Karen W and Curry, Cynthia and Olney, Ann Haskins and Sandoval, Claudio and Fisher, Jamie and Chong, Jessica Xiao-Ling and Pilchman, Lisa and Sahraoui, Rebecca and Stabley, Deborah L and Sol-Church, Katia} } @article {227, title = {Exome sequencing identifies a recurrent de novo ZSWIM6 mutation associated with acromelic frontonasal dysostosis.}, journal = {Am J Hum Genet}, volume = {95}, year = {2014}, month = {2014 Aug 07}, pages = {235-40}, abstract = {

Acromelic frontonasal dysostosis (AFND) is a rare disorder characterized by distinct craniofacial, brain, and limb malformations, including frontonasal dysplasia, interhemispheric lipoma, agenesis of the corpus callosum, tibial hemimelia, preaxial polydactyly of the feet, and intellectual disability. Exome sequencing of one trio and two unrelated probands revealed the same heterozygous variant (c.3487C>T [p. Arg1163Trp]) in a highly conserved protein domain of ZSWIM6; this variant has not been seen in the 1000 Genomes data, dbSNP, or the Exome Sequencing Project. Sanger validation of the three trios confirmed that the variant was de novo and was also present in a fourth isolated proband. In situ hybridization of early zebrafish embryos at 24 hr postfertilization (hpf) demonstrated telencephalic expression of zswim6 and onset of midbrain, hindbrain, and retinal expression at 48 hpf. Immunohistochemistry of later-stage mouse embryos demonstrated tissue-specific expression in the derivatives of all three germ layers. qRT-PCR expression analysis of osteoblast and fibroblast cell lines available from two probands was suggestive of Hedgehog pathway activation, indicating that the ZSWIM6 mutation associated with AFND may lead to the craniofacial, brain and limb malformations through the disruption of Hedgehog signaling.

}, keywords = {Abnormalities, Multiple, Amino Acid Sequence, Animals, Base Sequence, Craniofacial Abnormalities, DNA Mutational Analysis, DNA-Binding Proteins, Exome, Face, Hedgehog Proteins, Humans, Intellectual Disability, Limb Deformities, Congenital, Mandibulofacial Dysostosis, Mice, Molecular Sequence Data, Mutation, Protein Structure, Tertiary, Zebrafish, Zinc Fingers}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2014.07.008}, author = {Smith, Joshua D and Hing, Anne V and Clarke, Christine M and Johnson, Nathan M and Perez, Francisco A and Park, Sarah S and Horst, Jeremy A and Mecham, Brig and Maves, Lisa and Nickerson, Deborah A and Cunningham, Michael L} } @article {327, title = {Haploinsufficiency of SF3B4, a component of the pre-mRNA spliceosomal complex, causes Nager syndrome.}, journal = {Am J Hum Genet}, volume = {90}, year = {2012}, month = {2012 May 04}, pages = {925-33}, abstract = {

Nager syndrome, first described more than 60 years ago, is the archetype of a class of disorders called the acrofacial dysostoses, which are characterized by craniofacial and limb malformations. Despite intensive efforts, no gene for Nager syndrome has yet been identified. In an international collaboration, FORGE Canada and the National Institutes of Health Centers for Mendelian Genomics used exome sequencing as a discovery tool and found that mutations in SF3B4, a component of the U2 pre-mRNA spliceosomal complex, cause Nager syndrome. After Sanger sequencing of SF3B4 in a validation cohort, 20 of 35 (57\%) families affected by Nager syndrome had 1 of 18 different mutations, nearly all of which were frameshifts. These results suggest that most cases of Nager syndrome are caused by haploinsufficiency of SF3B4. Our findings add Nager syndrome to a growing list of disorders caused by mutations in genes that encode major components of the spliceosome and also highlight the synergistic potential of international collaboration when exome sequencing is applied in the search for genes responsible for rare Mendelian phenotypes.

}, keywords = {Adult, Child, Child, Preschool, Cohort Studies, Exome, Female, Haploinsufficiency, Humans, Limb Deformities, Congenital, Male, Mandibulofacial Dysostosis, Mutation, Reproducibility of Results, RNA Precursors, RNA Splicing Factors, RNA-Binding Proteins, Spliceosomes, Young Adult}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2012.04.004}, author = {Bernier, Francois P and Caluseriu, Oana and Ng, Sarah and Schwartzentruber, Jeremy and Buckingham, Kati J and Innes, A Micheil and Jabs, Ethylin Wang and Innis, Jeffrey W and Schuette, Jane L and Gorski, Jerome L and Byers, Peter H and Andelfinger, Gregor and Siu, Victoria and Lauzon, Julie and Fernandez, Bridget A and McMillin, Margaret and Scott, Richard H and Racher, Hilary and Majewski, Jacek and Nickerson, Deborah A and Shendure, Jay and Bamshad, Michael J and Parboosingh, Jillian S} }