@article {648, title = {Clinical, genetic, and pathologic characterization of Mexican founder mutation c.1387A>G.}, journal = {Neurol Genet}, volume = {5}, year = {2019}, month = {2019 Apr}, pages = {e315}, abstract = {

Objective: To characterize the clinical phenotype, genetic origin, and muscle pathology of patients with the c.1387A>G mutation.

Methods: Standardized clinical data were collected for all patients known to the authors with c.1387A>G mutations in . Muscle biopsies were reviewed and used for histopathology, immunostaining, Western blotting, and DNA extraction. Genetic analysis was performed on extracted DNA.

Results: We report the clinical phenotypes of 6 patients homozygous for the c.1387A>G mutation in . Onset of symptoms was <2 years, and 5 of the 6 patients never learned to walk. Brain MRIs were normal. Cognition was normal to mildly impaired. Microarray analysis of 5 homozygous c.1387A>G patients revealed a 500-kb region of shared homozygosity at 19q13.32, including . All 4 muscle biopsies available for review showed end-stage dystrophic pathology, near absence of glycosylated α-dystroglycan (α-DG) by immunofluorescence, and reduced molecular weight of α-DG compared with controls and patients with homozygous c.826C>A limb-girdle muscular dystrophy.

Conclusions: The clinical features and muscle pathology in these newly reported patients homozygous for c.1387A>G confirm that this mutation causes congenital muscular dystrophy. The clinical severity might be explained by the greater reduction in α-DG glycosylation compared with that seen with the c.826C>A mutation. The shared region of homozygosity at 19q13.32 indicates that c.1387A>G is a founder mutation with an estimated age of 60 generations (\~{}1,200-1,500 years).

}, issn = {2376-7839}, doi = {10.1212/NXG.0000000000000315}, author = {Lee, Angela J and Jones, Karra A and Butterfield, Russell J and Cox, Mary O and Konersman, Chamindra G and Grosmann, Carla and Abdenur, Jose E and Boyer, Monica and Beson, Brent and Wang, Ching and Dowling, James J and Gibbons, Melissa A and Ballard, Alison and Janas, Joanne S and Leshner, Robert T and Donkervoort, Sandra and B{\"o}nnemann, Carsten G and Malicki, Denise M and Weiss, Robert B and Moore, Steven A and Mathews, Katherine D} } @article {678, title = {Heterozygous Variants in KMT2E Cause a Spectrum of Neurodevelopmental Disorders and Epilepsy.}, journal = {Am J Hum Genet}, volume = {104}, year = {2019}, month = {2019 Jun 06}, pages = {1210-1222}, abstract = {

We delineate a KMT2E-related neurodevelopmental disorder on the basis of 38 individuals in 36 families. This study includes 31 distinct heterozygous variants in KMT2E (28 ascertained from Matchmaker Exchange and three previously reported), and four individuals with chromosome 7q22.2-22.23 microdeletions encompassing KMT2E (one previously reported). Almost all variants occurred de novo, and most were truncating. Most affected individuals with protein-truncating variants presented with mild intellectual disability. One-quarter of individuals met criteria for autism. Additional common features include macrocephaly, hypotonia, functional gastrointestinal abnormalities, and a subtle facial gestalt. Epilepsy was present in about one-fifth of individuals with truncating variants and was responsive to treatment with anti-epileptic medications in almost all. More than 70\% of the individuals were male, and expressivity was variable by sex; epilepsy was more common in females and autism more common in males. The four individuals with microdeletions encompassing KMT2E generally presented similarly to those with truncating variants, but the degree of developmental delay was greater. The group of four individuals with missense variants in KMT2E presented with the most severe developmental delays. Epilepsy was present in all individuals with missense variants, often manifesting as treatment-resistant infantile epileptic encephalopathy. Microcephaly was also common in this group. Haploinsufficiency versus gain-of-function or dominant-negative effects specific to these missense variants in KMT2E might explain this divergence in phenotype, but requires independent validation. Disruptive variants in KMT2E are an under-recognized cause of neurodevelopmental abnormalities.

}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2019.03.021}, author = {O{\textquoteright}Donnell-Luria, Anne H and Pais, Lynn S and Faundes, V{\'\i}ctor and Wood, Jordan C and Sveden, Abigail and Luria, Victor and Abou Jamra, Rami and Accogli, Andrea and Amburgey, Kimberly and Anderlid, Britt Marie and Azzarello-Burri, Silvia and Basinger, Alice A and Bianchini, Claudia and Bird, Lynne M and Buchert, Rebecca and Carr{\'e}, Wilfrid and Ceulemans, Sophia and Charles, Perrine and Cox, Helen and Culliton, Lisa and Curr{\`o}, Aurora and Demurger, Florence and Dowling, James J and Duban-Bedu, Benedicte and Dubourg, Christ{\`e}le and Eiset, Saga Elise and Escobar, Luis F and Ferrarini, Alessandra and Haack, Tobias B and Hashim, Mona and Heide, Solveig and Helbig, Katherine L and Helbig, Ingo and Heredia, Raul and H{\'e}ron, Delphine and Isidor, Bertrand and Jonasson, Amy R and Joset, Pascal and Keren, Boris and Kok, Fernando and Kroes, Hester Y and Lavillaureix, Alino{\"e} and Lu, Xin and Maas, Saskia M and Maegawa, Gustavo H B and Marcelis, Carlo L M and Mark, Paul R and Masruha, Marcelo R and McLaughlin, Heather M and McWalter, Kirsty and Melchinger, Esther U and Mercimek-Andrews, Saadet and Nava, Caroline and Pendziwiat, Manuela and Person, Richard and Ramelli, Gian Paolo and Ramos, Luiza L P and Rauch, Anita and Reavey, Caitlin and Renieri, Alessandra and Rie{\ss}, Angelika and Sanchez-Valle, Amarilis and Sattar, Shifteh and Saunders, Carol and Schwarz, Niklas and Smol, Thomas and Srour, Myriam and Steindl, Katharina and Syrbe, Steffen and Taylor, Jenny C and Telegrafi, Aida and Thiffault, Isabelle and Trauner, Doris A and van der Linden, Helio and van Koningsbruggen, Silvana and Villard, Laurent and Vogel, Ida and Vogt, Julie and Weber, Yvonne G and Wentzensen, Ingrid M and Widjaja, Elysa and Zak, Jaroslav and Baxter, Samantha and Banka, Siddharth and Rodan, Lance H} } @article {364, title = {Improving genetic diagnosis in Mendelian disease with transcriptome sequencing.}, journal = {Sci Transl Med}, volume = {9}, year = {2017}, month = {2017 04 19}, abstract = {

Exome and whole-genome sequencing are becoming increasingly routine approaches in Mendelian disease diagnosis. Despite their success, the current diagnostic rate for genomic analyses across a variety of rare diseases is approximately 25 to 50\%. We explore the utility of transcriptome sequencing [RNA sequencing (RNA-seq)] as a complementary diagnostic tool in a cohort of 50 patients with genetically undiagnosed rare muscle disorders. We describe an integrated approach to analyze patient muscle RNA-seq, leveraging an analysis framework focused on the detection of transcript-level changes that are unique to the patient compared to more than 180 control skeletal muscle samples. We demonstrate the power of RNA-seq to validate candidate splice-disrupting mutations and to identify splice-altering variants in both exonic and deep intronic regions, yielding an overall diagnosis rate of 35\%. We also report the discovery of a highly recurrent de novo intronic mutation in that results in a dominantly acting splice-gain event, disrupting the critical glycine repeat motif of the triple helical domain. We identify this pathogenic variant in a total of 27 genetically unsolved patients in an external collagen VI-like dystrophy cohort, thus explaining approximately 25\% of patients clinically suggestive of having collagen VI dystrophy in whom prior genetic analysis is negative. Overall, this study represents a large systematic application of transcriptome sequencing to rare disease diagnosis and highlights its utility for the detection and interpretation of variants missed by current standard diagnostic approaches.

}, keywords = {Collagen Type VI, High-Throughput Nucleotide Sequencing, Humans, Muscular Diseases, Mutation, Transcriptome}, issn = {1946-6242}, doi = {10.1126/scitranslmed.aal5209}, author = {Cummings, Beryl B and Marshall, Jamie L and Tukiainen, Taru and Lek, Monkol and Donkervoort, Sandra and Foley, A Reghan and Bolduc, Veronique and Waddell, Leigh B and Sandaradura, Sarah A and O{\textquoteright}Grady, Gina L and Estrella, Elicia and Reddy, Hemakumar M and Zhao, Fengmei and Weisburd, Ben and Karczewski, Konrad J and O{\textquoteright}Donnell-Luria, Anne H and Birnbaum, Daniel and Sarkozy, Anna and Hu, Ying and Gonorazky, Hernan and Claeys, Kristl and Joshi, Himanshu and Bournazos, Adam and Oates, Emily C and Ghaoui, Roula and Davis, Mark R and Laing, Nigel G and Topf, Ana and Kang, Peter B and Beggs, Alan H and North, Kathryn N and Straub, Volker and Dowling, James J and Muntoni, Francesco and Clarke, Nigel F and Cooper, Sandra T and B{\"o}nnemann, Carsten G and MacArthur, Daniel G} }