@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 {406, title = {SMCHD1 mutations associated with a rare muscular dystrophy can also cause isolated arhinia and Bosma arhinia microphthalmia syndrome.}, journal = {Nat Genet}, volume = {49}, year = {2017}, month = {2017 Feb}, pages = {238-248}, abstract = {

Arhinia, or absence of the nose, is a rare malformation of unknown etiology that is often accompanied by ocular and reproductive defects. Sequencing of 40 people with arhinia revealed that 84\% of probands harbor a missense mutation localized to a constrained region of SMCHD1 encompassing the ATPase domain. SMCHD1 mutations cause facioscapulohumeral muscular dystrophy type 2 (FSHD2) via a trans-acting loss-of-function epigenetic mechanism. We discovered shared mutations and comparable DNA hypomethylation patterning between these distinct disorders. CRISPR/Cas9-mediated alteration of smchd1 in zebrafish yielded arhinia-relevant phenotypes. Transcriptome and protein analyses in arhinia probands and controls showed no differences in SMCHD1 mRNA or protein abundance but revealed regulatory changes in genes and pathways associated with craniofacial patterning. Mutations in SMCHD1 thus contribute to distinct phenotypic spectra, from craniofacial malformation and reproductive disorders to muscular dystrophy, which we speculate to be consistent with oligogenic mechanisms resulting in pleiotropic outcomes.

}, keywords = {Adolescent, Child, Child, Preschool, Choanal Atresia, Chromosomal Proteins, Non-Histone, Female, Genetic Predisposition to Disease, Humans, Infant, Male, Microphthalmos, Muscular Dystrophies, Mutation, Nose, Phenotype}, issn = {1546-1718}, doi = {10.1038/ng.3743}, author = {Shaw, Natalie D and Brand, Harrison and Kupchinsky, Zachary A and Bengani, Hemant and Plummer, Lacey and Jones, Takako I and Erdin, Serkan and Williamson, Kathleen A and Rainger, Joe and Stortchevoi, Alexei and Samocha, Kaitlin and Currall, Benjamin B and Dunican, Donncha S and Collins, Ryan L and Willer, Jason R and Lek, Angela and Lek, Monkol and Nassan, Malik and Pereira, Shahrin and Kammin, Tammy and Lucente, Diane and Silva, Alexandra and Seabra, Catarina M and Chiang, Colby and An, Yu and Ansari, Morad and Rainger, Jacqueline K and Joss, Shelagh and Smith, Jill Clayton and Lippincott, Margaret F and Singh, Sylvia S and Patel, Nirav and Jing, Jenny W and Law, Jennifer R and Ferraro, Nalton and Verloes, Alain and Rauch, Anita and Steindl, Katharina and Zweier, Markus and Scheer, Ianina and Sato, Daisuke and Okamoto, Nobuhiko and Jacobsen, Christina and Tryggestad, Jeanie and Chernausek, Steven and Schimmenti, Lisa A and Brasseur, Benjamin and Cesaretti, Claudia and Garc{\'\i}a-Ortiz, Jose E and Buitrago, Tatiana Pineda and Silva, Orlando Perez and Hoffman, Jodi D and M{\"u}hlbauer, Wolfgang and Ruprecht, Klaus W and Loeys, Bart L and Shino, Masato and Kaindl, Angela M and Cho, Chie-Hee and Morton, Cynthia C and Meehan, Richard R and van Heyningen, Veronica and Liao, Eric C and Balasubramanian, Ravikumar and Hall, Janet E and Seminara, Stephanie B and Macarthur, Daniel and Moore, Steven A and Yoshiura, Koh-Ichiro and Gusella, James F and Marsh, Joseph A and Graham, John M and Lin, Angela E and Katsanis, Nicholas and Jones, Peter L and Crowley, William F and Davis, Erica E and FitzPatrick, David R and Talkowski, Michael E} }