@article {720, title = {Xq22 deletions and correlation with distinct neurological disease traits in females: Further evidence for a contiguous gene syndrome.}, journal = {Hum Mutat}, volume = {41}, year = {2020}, month = {2020 01}, pages = {150-168}, abstract = {

Xq22 deletions that encompass PLP1 (Xq22-PLP1-DEL) are notable for variable expressivity of neurological disease traits in females ranging from a mild late-onset form of spastic paraplegia type 2 (MIM$\#$ 312920), sometimes associated with skewed X-inactivation, to an early-onset neurological disease trait (EONDT) of severe developmental delay, intellectual disability, and behavioral abnormalities. Size and gene content of Xq22-PLP1-DEL vary and were proposed as potential molecular etiologies underlying variable expressivity in carrier females where two smallest regions of overlap (SROs) were suggested to influence disease. We ascertained a cohort of eight unrelated patients harboring Xq22-PLP1-DEL and performed high-density array comparative genomic hybridization~and breakpoint-junction sequencing. Molecular characterization of Xq22-PLP1-DEL from 17 cases (eight herein and nine published) revealed an overrepresentation of breakpoints that reside within repeats (11/17, ~65\%) and the clustering of ~47\% of proximal breakpoints in a genomic instability hotspot with characteristic non-B DNA density. These findings implicate a potential role for genomic architecture in stimulating the formation of Xq22-PLP1-DEL. The correlation of Xq22-PLP1-DEL gene content with neurological disease trait in female cases enabled refinement of the associated SROs to a single genomic interval containing six genes. Our data support the hypothesis that genes contiguous to PLP1 contribute to EONDT.

}, keywords = {Child, Child, Preschool, Chromosome Breakpoints, Chromosome Deletion, Chromosome Mapping, Chromosomes, Human, X, Comparative Genomic Hybridization, Female, Genetic Association Studies, Genetic Predisposition to Disease, Humans, Male, Nervous System Diseases, Pedigree, Phenotype, Quantitative Trait, Heritable, Repetitive Sequences, Nucleic Acid, Sex Factors, Syndrome, X Chromosome Inactivation}, issn = {1098-1004}, doi = {10.1002/humu.23902}, author = {Hijazi, Hadia and Coelho, Fernanda S and Gonzaga-Jauregui, Claudia and Bernardini, Laura and Mar, Soe S and Manning, Melanie A and Hanson-Kahn, Andrea and Naidu, Sakkubai and Srivastava, Siddharth and Lee, Jennifer A and Jones, Julie R and Friez, Michael J and Alberico, Thomas and Torres, Barbara and Fang, Ping and Cheung, Sau Wai and Song, Xiaofei and Davis-Williams, Angelique and Jornlin, Carly and Wight, Patricia A and Patyal, Pankaj and Taube, Jennifer and Poretti, Andrea and Inoue, Ken and Zhang, Feng and Pehlivan, Davut and Carvalho, Claudia M B and Hobson, Grace M and Lupski, James R} } @article {57, title = {Enrichment of mutations in chromatin regulators in people with Rett syndrome lacking mutations in MECP2.}, journal = {Genet Med}, volume = {19}, year = {2017}, month = {2017 01}, pages = {13-19}, abstract = {

PURPOSE: Rett syndrome (RTT) is a neurodevelopmental disorder caused primarily by de novo mutations in MECP2 and sometimes in CDKL5 and FOXG1. However, some RTT patients lack mutations in these genes.

METHODS: Twenty-two RTT patients without apparent MECP2, CDKL5, and FOXG1 mutations were subjected to both whole-exome sequencing and single-nucleotide polymorphism array-based copy-number variant (CNV) analyses.

RESULTS: Three patients had MECP2 mutations initially missed by clinical testing. Of the remaining 19, 17 (89.5\%) had 29 other likely pathogenic intragenic mutations and/or CNVs (10 patients had 2 or more). Interestingly, 13 patients had mutations in a gene/region previously reported in other neurodevelopmental disorders (NDDs), thereby providing a potential diagnostic yield of 68.4\%. These mutations were significantly enriched in chromatin regulators (corrected P = 0.0068) and moderately enriched in postsynaptic cell membrane molecules (corrected P = 0.076), implicating glutamate receptor signaling.

CONCLUSION: The genetic etiology of RTT without MECP2, CDKL5, and FOXG1 mutations is heterogeneous, overlaps with other NDDs, and complicated by a high mutation burden. Dysregulation of chromatin structure and abnormal excitatory synaptic signaling may form two common pathological bases of RTT.Genet Med 19 1, 13-19.

}, keywords = {Adolescent, Adult, Child, Child, Preschool, Chromatin, DNA Copy Number Variations, Female, Forkhead Transcription Factors, Humans, Infant, Male, Methyl-CpG-Binding Protein 2, Mutation, Nerve Tissue Proteins, Polymorphism, Single Nucleotide, Protein-Serine-Threonine Kinases, Rett Syndrome, Whole Exome Sequencing}, issn = {1530-0366}, doi = {10.1038/gim.2016.42}, author = {Sajan, Samin A and Jhangiani, Shalini N and Muzny, Donna M and Gibbs, Richard A and Lupski, James R and Glaze, Daniel G and Kaufmann, Walter E and Skinner, Steven A and Annese, Fran and Friez, Michael J and Lane, Jane and Percy, Alan K and Neul, Jeffrey L} }