@article {214, title = {Truncating mutations in the last exon of NOTCH3 cause lateral meningocele syndrome.}, journal = {Am J Med Genet A}, volume = {167A}, year = {2015}, month = {2015 Feb}, pages = {271-81}, abstract = {

Lateral meningocele syndrome (LMS, OMIM\%130720), also known as Lehman syndrome, is a very rare skeletal disorder with facial anomalies, hypotonia and meningocele-related neurologic dysfunction. The characteristic lateral meningoceles represent the severe end of the dural ectasia spectrum and are typically most severe in the lower spine. Facial features of LMS include hypertelorism and telecanthus, high arched eyebrows, ptosis, midfacial hypoplasia, micrognathia, high and narrow palate, low-set ears and a hypotonic appearance. Hyperextensibility, hernias and scoliosis reflect a connective tissue abnormality, and aortic dilation, a high-pitched nasal voice, wormian bones and osteolysis may be present. Lateral meningocele syndrome has phenotypic overlap with Hajdu-Cheney syndrome. We performed exome resequencing in five unrelated individuals with LMS and identified heterozygous truncating NOTCH3 mutations. In an additional unrelated individual Sanger sequencing revealed a deleterious variant in the same exon 33. In total, five novel de novo NOTCH3 mutations were identified in six unrelated patients. One had a 26 bp deletion (c.6461_6486del, p.G2154fsTer78), two carried the same single base pair insertion (c.6692_93insC, p.P2231fsTer11), and three individuals had a nonsense point mutation at c.6247A > T (pK2083*), c.6663C > G (p.Y2221*) or c.6732C > A, (p.Y2244*). All mutations cluster into the last coding exon, resulting in premature termination of the protein and truncation of the negative regulatory proline-glutamate-serine-threonine rich PEST domain. Our results suggest that mutant mRNA products escape nonsense mediated decay. The truncated NOTCH3 may cause gain-of-function through decreased clearance of the active intracellular product, resembling NOTCH2 mutations in the clinically related Hajdu-Cheney syndrome and contrasting the NOTCH3 missense mutations causing CADASIL.

}, keywords = {Abnormalities, Multiple, Child, Child, Preschool, DNA Mutational Analysis, Exome, Exons, Facies, High-Throughput Nucleotide Sequencing, Humans, Magnetic Resonance Imaging, Male, Meningocele, Mutation, Phenotype, Receptor, Notch3, Receptors, Notch, Young Adult}, issn = {1552-4833}, doi = {10.1002/ajmg.a.36863}, author = {Gripp, Karen W and Robbins, Katherine M and Sobreira, Nara L and Witmer, P Dane and Bird, Lynne M and Avela, Kristiina and M{\"a}kitie, Outi and Alves, Daniela and Hogue, Jacob S and Zackai, Elaine H and Doheny, Kimberly F and Stabley, Deborah L and Sol-Church, Katia} } @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 {228, title = {Mutations in LAMA1 cause cerebellar dysplasia and cysts with and without retinal dystrophy.}, journal = {Am J Hum Genet}, volume = {95}, year = {2014}, month = {2014 Aug 07}, pages = {227-34}, abstract = {

Cerebellar dysplasia with cysts (CDC) is an imaging finding typically seen in combination with cobblestone cortex and congenital muscular dystrophy in individuals with dystroglycanopathies. More recently, CDC was reported in seven children without neuromuscular involvement (Poretti-Boltshauser syndrome). Using a combination of homozygosity mapping and whole-exome sequencing, we identified biallelic mutations in LAMA1 as the cause of CDC in seven affected individuals (from five families) independent from those included in the phenotypic description of Poretti-Boltshauser syndrome. Most of these individuals also have high myopia, and some have retinal dystrophy and patchy increased T2-weighted fluid-attenuated inversion recovery (T2/FLAIR) signal in cortical white matter. In one additional family, we identified two siblings who have truncating LAMA1 mutations in combination with retinal dystrophy and mild cerebellar dysplasia without cysts, indicating that cysts are not an obligate feature associated with loss of LAMA1 function. This work expands the phenotypic spectrum associated with the lamininopathy disorders and highlights the tissue-specific roles played by different laminin-encoding genes.

}, keywords = {Adult, Alleles, Base Sequence, Cerebellar Cortex, Cerebellar Diseases, Child, Child, Preschool, Cysts, Exome, Female, Humans, Laminin, Male, Muscular Dystrophies, Retinal Dystrophies, Sequence Analysis, DNA, Young Adult}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2014.07.007}, author = {Aldinger, Kimberly A and Mosca, Stephen J and T{\'e}treault, Martine and Dempsey, Jennifer C and Ishak, Gisele E and Hartley, Taila and Phelps, Ian G and Lamont, Ryan E and O{\textquoteright}Day, Diana R and Basel, Donald and Gripp, Karen W and Baker, Laura and Stephan, Mark J and Bernier, Francois P and Boycott, Kym M and Majewski, Jacek and Parboosingh, Jillian S and Innes, A Micheil and Doherty, Dan} }