@article {979, title = {Exome sequencing identifies novel missense and deletion variants in RTN4IP1 associated with optic atrophy, global developmental delay, epilepsy, ataxia, and choreoathetosis.}, journal = {Am J Med Genet A}, volume = {185}, year = {2021}, month = {2021 01}, pages = {203-207}, abstract = {

Inherited optic neuropathies (IONs) are neurodegenerative disorders characterized by optic atrophy with or without extraocular manifestations. Optic atrophy-10 (OPA10) is an autosomal recessive ION recently reported to be caused by mutations in RTN4IP1, which encodes reticulon 4 interacting protein 1 (RTN4IP1), a mitochondrial ubiquinol oxydo-reductase. Here we report novel compound heterozygous mutations in RTN4IP1 in a male proband with developmental delay, epilepsy, optic atrophy, ataxia, and choreoathetosis. Workup was notable for transiently elevated lactate and lactate-to-pyruvate ratio, brain magnetic resonance imaging with optic atrophy and T2 signal abnormalities, and a nondiagnostic initial genetic workup, including chromosomal microarray and mitochondrial panel testing. Exome sequencing identified a paternally inherited missense variant (c.263T>G, p.Val88Gly) predicted to be deleterious and a maternally inherited deletion encompassing RTN4IP1. To our knowledge, this is the first report of a non-single nucleotide pathogenic variant associated with OPA10. This case highlights the expanding phenotypic spectrum of OPA10, the association between "syndromic" cases and severe RTN4IP1 mutations, and the importance of nonbiased genetic testing, such as ES, to analyze multiple genes and variants types, in patients suspected of having genetic disease.

}, issn = {1552-4833}, doi = {10.1002/ajmg.a.61910}, author = {D{\textquoteright}Gama, Alissa M and England, Eleina and Madden, Jill A and Shi, JiAHi and Chao, Katherine R and Wojcik, Monica H and Torres, Alcy R and Tan, Wen-Hann and Berry, Gerard T and Prabhu, Sanjay P and Agrawal, Pankaj B} } @article {974, title = {Variants in GNAI1 cause a syndrome associated with variable features including developmental delay, seizures, and hypotonia.}, journal = {Genet Med}, volume = {23}, year = {2021}, month = {2021 05}, pages = {881-887}, abstract = {

PURPOSE: Neurodevelopmental disorders (NDDs) encompass a spectrum of genetically heterogeneous disorders with features that commonly include developmental delay, intellectual disability, and autism spectrum disorders. We sought to delineate the molecular and phenotypic spectrum of a novel neurodevelopmental disorder caused by variants in the GNAI1 gene.

METHODS: Through large cohort trio-based exome sequencing and international data-sharing, we identified 24 unrelated individuals with NDD phenotypes and a variant in GNAI1, which encodes the inhibitory Gαi1 subunit of heterotrimeric G-proteins. We collected detailed genotype and phenotype information for each affected individual.

RESULTS: We identified 16 unique variants in GNAI1 in 24 affected individuals; 23 occurred de novo and 1 was inherited from a mosaic parent. Most affected individuals have a severe neurodevelopmental disorder. Core features include global developmental delay, intellectual disability, hypotonia, and epilepsy.

CONCLUSION: This collaboration establishes GNAI1 variants as a cause of NDDs. GNAI1-related NDD is most often characterized by severe to profound delays, hypotonia, epilepsy that ranges from self-limiting to intractable, behavior problems, and variable mild dysmorphic features.

}, keywords = {Child, Developmental Disabilities, Humans, Intellectual Disability, Muscle Hypotonia, Neurodevelopmental Disorders, Seizures, Whole Exome Sequencing}, issn = {1530-0366}, doi = {10.1038/s41436-020-01076-8}, author = {Muir, Alison M and Gardner, Jennifer F and van Jaarsveld, Richard H and de Lange, Iris M and van der Smagt, Jasper J and Wilson, Golder N and Dubbs, Holly and Goldberg, Ethan M and Zitano, Lia and Bupp, Caleb and Martinez, Jose and Srour, Myriam and Accogli, Andrea and Alhakeem, Afnan and Meltzer, Meira and Gropman, Andrea and Brewer, Carole and Caswell, Richard C and Montgomery, Tara and McKenna, Caoimhe and McKee, Shane and Powell, Corinna and Vasudevan, Pradeep C and Brady, Angela F and Joss, Shelagh and Tysoe, Carolyn and Noh, Grace and Tarnopolsky, Mark and Brady, Lauren and Zafar, Muhammad and Schrier Vergano, Samantha A and Murray, Brianna and Sawyer, Lindsey and Hainline, Bryan E and Sapp, Katherine and DeMarzo, Danielle and Huismann, Darcy J and Wentzensen, Ingrid M and Schnur, Rhonda E and Monaghan, Kristin G and Juusola, Jane and Rhodes, Lindsay and Dobyns, William B and Lecoquierre, Francois and Goldenberg, Alice and Polster, Tilman and Axer-Schaefer, Susanne and Platzer, Konrad and Kl{\"o}ckner, Chiara and Hoffman, Trevor L and MacArthur, Daniel G and O{\textquoteright}Leary, Melanie C and VanNoy, Grace E and England, Eleina and Varghese, Vinod C and Mefford, Heather C} } @article {943, title = {Expanding the disease phenotype of ADSSL1-associated myopathy in non-Korean patients.}, journal = {Neuromuscul Disord}, volume = {30}, year = {2020}, month = {2020 04}, pages = {310-314}, abstract = {

Adenylosuccinate synthase (ADSSL1) is a muscle specific enzyme involved in the purine nucleotide cycle and responsible for the conversion of inosine monophosphate to adenosine monophosphate. Since 2016, when mutations in the ADSSL1 gene were first described to be associated with an adult onset distal myopathy, nine patients with compound heterozygous variants in the ADSSL1 gene, all of Korean origin, have been identified. Here we report a novel ADSSL1 mutation and describe two sporadic cases of Turkish and Indian origin. Many of the clinical features of both patients and muscle histopathology and muscle MRI findings, were in accordance with previously reported findings in the adult onset distal myopathy individuals. However, one of our patients presented with progressive, proximally pronounced weakness, severe muscle atrophy and early contractures. Thus, mutations in ADSSL1 have to be considered in patients with both distal and proximal muscle weakness and across various ethnicities.

}, issn = {1873-2364}, doi = {10.1016/j.nmd.2020.02.006}, author = {Mroczek, Magdalena and Durmus, Hacer and Bijarnia-MAHy, Sunita and Topf, Ana and Ghaoui, Roula and Bryen, Samantha and Duff, Jennifer and England, Eleina and Cooper, Sandra T and MacArthur, Daniel G and Straub, Volker} } @article {693, title = {MAGEL2-related disorders: A study and case series.}, journal = {Clin Genet}, volume = {96}, year = {2019}, month = {2019 Dec}, pages = {493-505}, abstract = {

Pathogenic MAGEL2 variants result in the phenotypes of Chitayat-Hall syndrome (CHS), Schaaf-Yang syndrome (SYS) and Prader-Willi syndrome (PWS). We present five patients with mutations in MAGEL2, including the first patient reported with a missense variant, adding to the limited literature. Further, we performed a systematic review of the CHS and SYS literature, assess the overlap between CHS, SYS and PWS, and analyze genotype-phenotype correlations among them. We conclude that there is neither a clinical nor etiological difference between CHS and SYS, and propose that the two syndromes simply be referred to as MAGEL2-related disorders.

}, issn = {1399-0004}, doi = {10.1111/cge.13620}, author = {Patak, Jameson and Gilfert, James and Byler, Melissa and Neerukonda, Vamsee and Thiffault, Isabelle and Cross, Laura and Amudhavalli, Shivarajan and Pacio-Miguez, Marta and Palomares-Bralo, Maria and Garcia-Minaur, Sixto and Santos-Simarro, Fernando and Powis, Z{\"o}e and Alcaraz, Wendy and Tang, Sha and Jurgens, Julie and Barry, Brenda and England, Eleina and Engle, Elizabeth and Hess, Jonathon and Lebel, Robert R} }