@article {999, title = {DLG4-related synaptopathy: a new rare brain disorder.}, journal = {Genet Med}, volume = {23}, year = {2021}, month = {2021 05}, pages = {888-899}, abstract = {

PURPOSE: Postsynaptic density protein-95 (PSD-95), encoded by DLG4, regulates excitatory synaptic function in the brain. Here we present the clinical and genetic features of 53 patients (42 previously unpublished) with DLG4 variants.

METHODS: The clinical and genetic information were~collected through GeneMatcher collaboration. All the individuals were investigated by local clinicians and the gene variants were identified by clinical exome/genome sequencing.

RESULTS: The clinical picture was predominated by early onset global developmental delay, intellectual disability, autism spectrum disorder, and attention deficit-hyperactivity disorder, all of which point to a brain disorder. Marfanoid habitus, which was previously suggested to be a characteristic feature of DLG4-related phenotypes, was found in only nine individuals and despite some overlapping features, a distinct facial dysmorphism could not~be established. Of the 45 different DLG4 variants, 39 were predicted to lead to loss of protein function and the majority occurred de novo (four with unknown origin). The six missense variants identified were suggested to lead to structural or functional changes by protein modeling studies.

CONCLUSION: The present study shows that clinical manifestations associated with DLG4 overlap with those found in other neurodevelopmental disorders of synaptic dysfunction; thus, we designate this group of disorders as DLG4-related synaptopathy.

}, keywords = {Autism Spectrum Disorder, Brain, Brain Diseases, Disks Large Homolog 4 Protein, Humans, Intellectual Disability, Neurodevelopmental Disorders, Phenotype}, issn = {1530-0366}, doi = {10.1038/s41436-020-01075-9}, author = {Rodr{\'\i}guez-Palmero, Agust{\'\i} and Boerrigter, Melissa Maria and G{\'o}mez-Andr{\'e}s, David and Aldinger, Kimberly A and Marcos-Alcalde, {\'I}{\~n}igo and Popp, Bernt and Everman, David B and Lovgren, Alysia Kern and Arpin, Stephanie and Bahrambeigi, Vahid and Beunders, Gea and Bisgaard, Anne-Marie and Bjerregaard, V A and Bruel, Ange-Line and Challman, Thomas D and Cogn{\'e}, Benjamin and Coubes, Christine and de Man, Stella A and Denomm{\'e}-Pichon, Anne-Sophie and Dye, Thomas J and Elmslie, Frances and Feuk, Lars and Garcia-Minaur, Sixto and Gertler, Tracy and Giorgio, Elisa and Gruchy, Nicolas and Haack, Tobias B and Haldeman-Englert, Chad R and Haukanes, Bj{\o}rn Ivar and Hoyer, Juliane and Hurst, Anna C E and Isidor, Bertrand and Soller, Maria Johansson and Kushary, Sulagna and Kvarnung, Malin and Landau, Yuval E and Leppig, Kathleen A and Lindstrand, Anna and Kleinendorst, Lotte and MacKenzie, Alex and Mandrile, Giorgia and Mendelsohn, Bryce A and Moghadasi, Setareh and Morton, Jenny E and Moutton, S{\'e}bastien and M{\"u}ller, Amelie J and O{\textquoteright}Leary, Melanie and Pacio-Miguez, Marta and Palomares-Bralo, Maria and Parikh, Sumit and Pfundt, Rolph and Pode-Shakked, Ben and Rauch, Anita and Repnikova, Elena and Revah-Politi, Anya and Ross, Meredith J and Ruivenkamp, Claudia A L and Sarrazin, Elisabeth and Savatt, Juliann M and Schluter, Agatha and Sch{\"o}newolf-Greulich, Bitten and Shad, Zohra and Shaw-Smith, Charles and Shieh, Joseph T and Shohat, Motti and Spranger, Stephanie and Thiese, Heidi and Mau-Them, Frederic Tran and van Bon, Bregje and van de Burgt, Ineke and van de Laar, Ingrid M B H and van Drie, Esm{\'e}e and van Haelst, Mieke M and van Ravenswaaij-Arts, Conny M and Verdura, Edgard and Vitobello, Antonio and Waldm{\"u}ller, Stephan and Whiting, Sharon and Zweier, Christiane and Prada, Carlos E and de Vries, Bert B A and Dobyns, William B and Reiter, Simone F and G{\'o}mez-Puertas, Paulino and Pujol, Aurora and T{\"u}mer, Zeynep} } @article {715, title = {Distinct patterns of complex rearrangements and a mutational signature of microhomeology are frequently observed in PLP1 copy number gain structural variants.}, journal = {Genome Med}, volume = {11}, year = {2019}, month = {2019 12 09}, pages = {80}, abstract = {

BACKGROUND: We investigated the features of the genomic rearrangements in a cohort of 50 male individuals with proteolipid protein 1 (PLP1) copy number gain events who were ascertained with Pelizaeus-Merzbacher disease (PMD; MIM: 312080). We then compared our new data to previous structural variant mutagenesis studies involving the Xq22 region of the human genome. The aggregate data from 159 sequenced join-points (discontinuous sequences in the reference genome that are joined during the rearrangement process) were studied. Analysis of these data from 150 individuals enabled the spectrum and relative distribution of the underlying genomic mutational signatures to be delineated.

METHODS: Genomic rearrangements in PMD individuals with PLP1 copy number gain events were investigated by high-density customized array or clinical chromosomal microarray analysis and breakpoint junction sequence analysis.

RESULTS: High-density customized array showed that the majority of cases (33/50; ~ 66\%) present with single duplications, although complex genomic rearrangements (CGRs) are also frequent (17/50; ~ 34\%). Breakpoint mapping to nucleotide resolution revealed further previously unknown structural and sequence complexities, even in single duplications. Meta-analysis of all studied rearrangements that occur at the PLP1 locus showed that single duplications were found in ~ 54\% of individuals and that, among all CGR cases, triplication flanked by duplications is the most frequent CGR array CGH pattern observed. Importantly, in ~ 32\% of join-points, there is evidence for a mutational signature of microhomeology (highly similar yet imperfect sequence matches).

CONCLUSIONS: These data reveal a high frequency of CGRs at the PLP1 locus and support the assertion that replication-based mechanisms are prominent contributors to the formation of CGRs at Xq22. We propose that microhomeology can facilitate template switching, by stabilizing strand annealing of the primer using W-C base complementarity, and is a mutational signature for replicative repair.

}, issn = {1756-994X}, doi = {10.1186/s13073-019-0676-0}, author = {Bahrambeigi, Vahid and Song, Xiaofei and Sperle, Karen and Beck, Christine R and Hijazi, Hadia and Grochowski, Christopher M and Gu, Shen and Seeman, Pavel and Woodward, Karen J and Carvalho, Claudia M B and Hobson, Grace M and Lupski, James R} }