@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 {826, title = {Molecular diagnosis in recessive pediatric neurogenetic disease can help reduce disease recurrence in families.}, journal = {BMC Med Genomics}, volume = {13}, year = {2020}, month = {2020 05 13}, pages = {68}, abstract = {

BACKGROUND: The causes for thousands of individually rare recessive diseases have been discovered since the adoption of next generation sequencing (NGS). Following the molecular diagnosis in older children in a family, parents could use this information to opt for fetal genotyping in subsequent pregnancies, which could inform decisions about elective termination of pregnancy. The use of NGS diagnostic sequencing in families has not been demonstrated to yield benefit in subsequent pregnancies to reduce recurrence. Here we evaluated whether genetic diagnosis in older children in families supports reduction in recurrence of recessive neurogenetic disease.

METHODS: Retrospective study involving families with a child with a recessive pediatric brain disease (rPBD) that underwent NGS-based molecular diagnosis. Prenatal molecular testing was offered to couples in which a molecular diagnosis was made, to help couples seeking to prevent recurrence. With this information, families made decisions about elective termination. Pregnancies that were carried to term were assessed for the health of child and mother, and compared with historic recurrence risk of recessive disease.

RESULTS: Between 2010 and 2016, 1172 families presented with a child a likely~rPBD, 526 families received a molecular diagnosis, 91 families returned to the clinic with 101 subsequent pregnancies, and 84 opted for fetal genotyping. Sixty tested negative for recurrence for the biallelic mutation~in the fetus, and all, except for one spontaneous abortion, carried to term, and were unaffected at follow-up. Of 24 that genotyped positive~for~the biallelic mutation, 16 were electively terminated, and 8 were carried to term and showed features of disease similar to that of the older~affected sibling(s). Among the 101 pregnancies, disease recurrence in living offspring deviated from the expected 25\% to the observed 12\% ([95\% CI 0{\textperiodcentered}04 to 0{\textperiodcentered}20], p = 0{\textperiodcentered}011).

CONCLUSIONS: Molecular diagnosis in an older child, coupled with prenatal fetal genotyping in subsequent pregnancies and genetic counselling, allows families to make informed decisions to reduce recessive neurogenetic disease recurrence.

}, keywords = {Child, Preschool, Female, Genes, Recessive, Genetic Markers, Genetic Predisposition to Disease, Genetic Testing, Genotype, High-Throughput Nucleotide Sequencing, Humans, Infant, Infant, Newborn, Male, Mutation, Nervous System Diseases, Pedigree, Pregnancy, Prenatal Diagnosis, Recurrence, Retrospective Studies}, issn = {1755-8794}, doi = {10.1186/s12920-020-0714-1}, author = {Issa, Mahmoud Y and Chechlacz, Zinayida and Stanley, Valentina and George, Renee D and McEvoy-Venneri, Jennifer and Belandres, Denice and Elbendary, Hasnaa M and Gaber, Khaled R and Nabil, Ahmed and Abdel-Hamid, Mohamed S and Zaki, MAH S and Gleeson, Joseph G} }