@article {949, title = {A relatively common homozygous TRAPPC4 splicing variant is associated with an early-infantile neurodegenerative syndrome.}, journal = {Eur J Hum Genet}, volume = {29}, year = {2021}, month = {2021 Feb}, pages = {271-279}, abstract = {

Trafficking protein particle (TRAPP) complexes, which include the TRAPPC4 protein, regulate membrane trafficking between lipid organelles in a process termed vesicular tethering. TRAPPC4 was recently implicated in a recessive neurodevelopmental condition in four unrelated families due to a shared c.454+3A>G splice variant. Here, we report 23 patients from 17 independent families with an early-infantile-onset neurodegenerative presentation, where we also identified the homozygous variant hg38:11:119020256 A>G (NM_016146.5:c.454+3A>G) in TRAPPC4 through exome or genome sequencing. No other clinically relevant TRAPPC4 variants were identified among any of over 10,000 patients with neurodevelopmental conditions. We found the carrier frequency of TRAPPC4 c.454+3A>G was 2.4-5.4 per 10,000 healthy individuals. Affected individuals with the homozygous TRAPPC4 c.454+3A>G variant showed profound psychomotor delay, developmental regression, early-onset epilepsy, microcephaly and progressive spastic tetraplegia. Based upon RNA sequencing, the variant resulted in partial exon 3 skipping and generation of an aberrant transcript owing to use of a downstream cryptic splice donor site, predicting a premature stop codon and nonsense mediated decay. These data confirm the pathogenicity of the TRAPPC4 c.454+3A>G variant, and refine the clinical presentation of TRAPPC4-related encephalopathy.

}, issn = {1476-5438}, doi = {10.1038/s41431-020-00717-5}, author = {Ghosh, Shereen G and Scala, Marcello and Beetz, Christian and Helman, Guy and Stanley, Valentina and Yang, Xiaoxu and Breuss, Martin W and Mazaheri, Neda and Selim, Laila and Hadipour, Fatemeh and Pais, Lynn and Stutterd, Chloe A and Karageorgou, Vasiliki and Begtrup, Amber and Crunk, Amy and Juusola, Jane and Willaert, Rebecca and Flore, Leigh A and Kennelly, Kelly and Spencer, Christopher and Brown, Martha and Trapane, Pamela and Hurst, Anna C E and Lane Rutledge, S and Goodloe, Dana H and McDonald, Marie T and Shashi, Vandana and Schoch, Kelly and Tomoum, Hoda and Zaitoun, Raghda and Hadipour, Zahra and Galehdari, Hamid and Pagnamenta, Alistair T and Mojarrad, Majid and Sedaghat, Alireza and Dias, Patr{\'\i}cia and Quintas, Sofia and Eslahi, Atiyeh and Shariati, Gholamreza and Bauer, Peter and Simons, Cas and Houlden, Henry and Issa, Mahmoud Y and Zaki, MAH S and Maroofian, Reza and Gleeson, Joseph G} } @article {491, title = {Dual Molecular Effects of Dominant RORA Mutations Cause Two Variants of Syndromic Intellectual Disability with Either Autism or Cerebellar Ataxia.}, journal = {Am J Hum Genet}, volume = {102}, year = {2018}, month = {2018 05 03}, pages = {744-759}, abstract = {

RORĪ±, the RAR-related orphan nuclear receptor alpha, is essential for cerebellar development. The spontaneous mutant mouse staggerer, with an ataxic gait caused by neurodegeneration of cerebellar Purkinje cells, was discovered two decades ago to result from homozygous intragenic Rora deletions. However, RORA mutations were hitherto undocumented in humans. Through a multi-centric collaboration, we identified three copy-number variant deletions (two de novo and one dominantly inherited in three generations), one de novo disrupting duplication, and nine de novo point mutations (three truncating, one canonical splice site, and five missense mutations) involving RORA in 16 individuals from 13 families with variable neurodevelopmental delay and intellectual disability (ID)-associated autistic features, cerebellar ataxia, and epilepsy. Consistent with the human and mouse data, disruption of the D.~rerio ortholog, roraa, causes significant reduction in the size of the developing cerebellum. Systematic in~vivo complementation studies showed that, whereas wild-type human RORA mRNA could complement the cerebellar pathology, missense variants had two distinct pathogenic mechanisms of either haploinsufficiency or a dominant toxic effect according to their localization in the ligand-binding or DNA-binding domains, respectively. This dichotomous direction of effect is likely relevant to the phenotype in humans: individuals with loss-of-function variants leading to haploinsufficiency show ID with autistic features, while individuals with de novo dominant toxic variants present with ID, ataxia, and cerebellar atrophy. Our combined genetic and functional data highlight the complex mutational landscape at the human RORA locus and suggest that dual mutational effects likely determine phenotypic outcome.

}, keywords = {Adolescent, Adult, Aged, 80 and over, Alleles, Animals, Autistic Disorder, Brain, Cerebellar Ataxia, Child, Child, Preschool, Disease Models, Animal, DNA Copy Number Variations, Female, Genes, Dominant, Genetic Complementation Test, Humans, Intellectual Disability, Larva, Magnetic Resonance Imaging, Male, Middle Aged, Mutation, Missense, Nuclear Receptor Subfamily 1, Group F, Member 1, Purkinje Cells, Syndrome, Zebrafish}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2018.02.021}, author = {Guissart, Claire and Latypova, X{\'e}nia and Rollier, Paul and Khan, Tahir N and Stamberger, Hannah and McWalter, Kirsty and Cho, Megan T and Kjaergaard, Susanne and Weckhuysen, Sarah and Lesca, Gaetan and Besnard, Thomas and {\~O}unap, Katrin and Schema, Lynn and Chiocchetti, Andreas G and McDonald, Marie and de Bellescize, Julitta and Vincent, Marie and Van Esch, Hilde and Sattler, Shannon and Forghani, Irman and Thiffault, Isabelle and Freitag, Christine M and Barbouth, Deborah Sara and Cadieux-Dion, Maxime and Willaert, Rebecca and Guillen Sacoto, Maria J and Safina, Nicole P and Dubourg, Christ{\`e}le and Grote, Lauren and Carr{\'e}, Wilfrid and Saunders, Carol and Pajusalu, Sander and Farrow, Emily and Boland, Anne and Karlowicz, Danielle Hays and Deleuze, Jean-Fran{\c c}ois and Wojcik, Monica H and Pressman, Rena and Isidor, Bertrand and Vogels, Annick and Van Paesschen, Wim and Al-Gazali, Lihadh and Al Shamsi, Aisha Mohamed and Claustres, Mireille and Pujol, Aurora and Sanders, Stephan J and Rivier, Fran{\c c}ois and Leboucq, Nicolas and Cogn{\'e}, Benjamin and Sasorith, Souphatta and Sanlaville, Damien and Retterer, Kyle and Odent, Sylvie and Katsanis, Nicholas and B{\'e}zieau, St{\'e}phane and Koenig, Michel and Davis, Erica E and Pasquier, Laurent and K{\"u}ry, S{\'e}bastien} } @article {464, title = {Truncating Variants in NAA15 Are Associated with Variable Levels of Intellectual Disability, Autism Spectrum Disorder, and Congenital Anomalies.}, journal = {Am J Hum Genet}, volume = {102}, year = {2018}, month = {2018 05 03}, pages = {985-994}, abstract = {

N-alpha-acetylation is a common co-translational protein modification that is essential for normal cell function in humans. We previously identified the genetic basis of an X-linked infantile lethal Mendelian disorder involving a c.109T>C (p.Ser37Pro) missense variant in NAA10, which encodes the catalytic subunit of the N-terminal acetyltransferase A (NatA) complex. The auxiliary subunit of the NatA complex, NAA15, is the dimeric binding partner for NAA10. Through a genotype-first approach with whole-exome or genome sequencing (WES/WGS) and targeted sequencing analysis, we identified and phenotypically characterized 38 individuals from 33 unrelated families with 25 different de novo or inherited, dominantly acting likely gene disrupting (LGD) variants in NAA15. Clinical features of affected individuals with LGD variants in NAA15 include variable levels of intellectual disability, delayed speech and motor milestones, and autism spectrum disorder. Additionally, mild craniofacial dysmorphology, congenital cardiac anomalies, and seizures are present in some subjects. RNA analysis in cell lines from two individuals showed degradation of the transcripts with LGD variants, probably as a result of nonsense-mediated decay. Functional assays in yeast confirmed a deleterious effect for two of the LGD variants in NAA15. Further supporting a mechanism of haploinsufficiency, individuals with copy-number variant (CNV) deletions involving NAA15 and surrounding genes can present with mild intellectual disability, mild dysmorphic features, motor delays, and decreased growth. We propose that defects in NatA-mediated N-terminal acetylation (NTA) lead to variable levels of neurodevelopmental disorders in humans, supporting the importance of the NatA complex in normal human development.

}, keywords = {Abnormalities, Multiple, Adolescent, Adult, Autism Spectrum Disorder, Cell Line, Child, Exons, Female, Gene Expression Regulation, Genetic Predisposition to Disease, Genetic Variation, Humans, Intellectual Disability, Male, Middle Aged, Mutation, N-Terminal Acetyltransferase A, N-Terminal Acetyltransferase E, Pedigree, Phenotype, RNA, Messenger, Saccharomyces cerevisiae}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2018.03.004}, author = {Cheng, Hanyin and Dharmadhikari, Avinash V and Varland, Sylvia and Ma, Ning and Domingo, Deepti and Kleyner, Robert and Rope, Alan F and Yoon, Margaret and Stray-Pedersen, Asbj{\o}rg and Posey, Jennifer E and Crews, Sarah R and Eldomery, Mohammad K and Akdemir, Zeynep Coban and Lewis, Andrea M and Sutton, Vernon R and Rosenfeld, Jill A and Conboy, Erin and Agre, Katherine and Xia, Fan and Walkiewicz, Magdalena and Longoni, Mauro and High, Frances A and van Slegtenhorst, Marjon A and Mancini, Grazia M S and Finnila, Candice R and van Haeringen, Arie and den Hollander, Nicolette and Ruivenkamp, Claudia and Naidu, Sakkubai and Mahida, Sonal and Palmer, Elizabeth E and Murray, Lucinda and Lim, Derek and Jayakar, Parul and Parker, Michael J and Giusto, Stefania and Stracuzzi, Emanuela and Romano, Corrado and Beighley, Jennifer S and Bernier, Raphael A and K{\"u}ry, S{\'e}bastien and Nizon, Mathilde and Corbett, Mark A and Shaw, Marie and Gardner, Alison and Barnett, Christopher and Armstrong, Ruth and Kassahn, Karin S and Van Dijck, Anke and Vandeweyer, Geert and Kleefstra, Tjitske and Schieving, Jolanda and Jongmans, Marjolijn J and de Vries, Bert B A and Pfundt, Rolph and Kerr, Bronwyn and Rojas, Samantha K and Boycott, Kym M and Person, Richard and Willaert, Rebecca and Eichler, Evan E and Kooy, R Frank and Yang, Yaping and Wu, Joseph C and Lupski, James R and Arnesen, Thomas and Cooper, Gregory M and Chung, Wendy K and Gecz, Jozef and Stessman, Holly A F and Meng, Linyan and Lyon, Gholson J} }