@article {924, title = {Mutations in Spliceosomal Genes PPIL1 and PRP17 Cause Neurodegenerative Pontocerebellar Hypoplasia with Microcephaly.}, journal = {Neuron}, volume = {109}, year = {2021}, month = {2021 01 20}, pages = {241-256.e9}, abstract = {

Autosomal-recessive cerebellar hypoplasia and ataxia constitute a group of heterogeneous brain disorders caused by disruption of several fundamental cellular processes. Here, we identified 10 families showing a neurodegenerative condition involving pontocerebellar hypoplasia with microcephaly (PCHM). Patients harbored biallelic mutations in genes encoding the spliceosome components Peptidyl-Prolyl Isomerase Like-1 (PPIL1) or Pre-RNA Processing-17 (PRP17). Mouse knockouts of either gene were lethal in early embryogenesis, whereas PPIL1 patient mutation knockin mice showed neuron-specific apoptosis. Loss of either protein affected splicing integrity, predominantly affecting short and high GC-content introns and genes involved in brain disorders. PPIL1 and PRP17 form an active isomerase-substrate interaction, but we found that isomerase activity is not critical for function. Thus, we establish disrupted splicing integrity and "major spliceosome-opathies" as a new mechanism underlying PCHM and neurodegeneration and uncover a non-enzymatic function of a spliceosomal proline isomerase.

}, keywords = {Amino Acid Sequence, Animals, Cell Cycle Proteins, Cerebellar Diseases, Cohort Studies, Female, Gene Knockout Techniques, HEK293 Cells, Heredodegenerative Disorders, Nervous System, Humans, Male, Mice, Mice, Inbred C57BL, Mice, Transgenic, Microcephaly, Mutation, Pedigree, Peptidylprolyl Isomerase, Protein Structure, Secondary, Protein Structure, Tertiary, RNA Splicing Factors, Spliceosomes}, issn = {1097-4199}, doi = {10.1016/j.neuron.2020.10.035}, author = {Chai, Guoliang and Webb, Alice and Li, Chen and Antaki, Danny and Lee, Sangmoon and Breuss, Martin W and Lang, Nhi and Stanley, Valentina and Anzenberg, Paula and Yang, Xiaoxu and Marshall, Trevor and Gaffney, Patrick and Wierenga, Klaas J and Chung, Brian Hon-Yin and Tsang, Mandy Ho-Yin and Pais, Lynn S and Lovgren, Alysia Kern and VanNoy, Grace E and Rehm, Heidi L and Mirzaa, Ghayda and Leon, Eyby and Diaz, Jullianne and Neumann, Alexander and Kalverda, Arnout P and Manfield, Iain W and Parry, David A and Logan, Clare V and Johnson, Colin A and Bonthron, David T and Valleley, Elizabeth M A and Issa, Mahmoud Y and Abdel-Ghafar, Sherif F and Abdel-Hamid, Mohamed S and Jennings, Patricia and Zaki, MAH S and Sheridan, Eamonn and Gleeson, Joseph G} } @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 {694, title = {Infant mortality: the contribution of genetic disorders.}, journal = {J Perinatol}, volume = {39}, year = {2019}, month = {2019 Dec}, pages = {1611-1619}, abstract = {

OBJECTIVE: To determine the proportion of infant deaths occurring in the setting of a confirmed genetic disorder.

STUDY DESIGN: A retrospective analysis of the electronic medical records of infants born from 1 January, 2011 to 1 June, 2017, who died prior to 1 year of age.

RESULTS: Five hundred and seventy three deceased infants were identified. One hundred and seventeen were confirmed to have a molecular or cytogenetic diagnosis in a clinical diagnostic laboratory and an additional seven were diagnosed by research testing for a total of 124/573 (22\%) diagnosed infants. A total of 67/124 (54\%) had chromosomal disorders and 58/124 (47\%) had single gene disorders (one infant had both). The proportion of diagnoses made by sequencing technologies, such as exome sequencing, increased over the years.

CONCLUSIONS: The prevalence of confirmed genetic disorders within our cohort of infant deaths is higher than that previously reported. Increased efforts are needed to further understand the mortality burden of genetic disorders in infancy.

}, issn = {1476-5543}, doi = {10.1038/s41372-019-0451-5}, author = {Wojcik, Monica H and Schwartz, Talia S and Thiele, Katri E and Paterson, Heather and Stadelmaier, Rachel and Mullen, Thomas E and VanNoy, Grace E and Genetti, Casie A and Madden, Jill A and Gubbels, Cynthia S and Yu, Timothy W and Tan, Wen-Hann and Agrawal, Pankaj B} }