@article {805, title = {Recurrent Rare Copy Number Variants Increase Risk for Esotropia.}, journal = {Invest Ophthalmol Vis Sci}, volume = {61}, year = {2020}, month = {2020 08 03}, pages = {22}, abstract = {

Purpose: To determine whether rare copy number variants (CNVs) increase risk for comitant esotropia.

Methods: CNVs were identified in 1614 Caucasian individuals with comitant esotropia and 3922 Caucasian controls from Illumina SNP genotyping using two Hidden Markov model (HMM) algorithms, PennCNV and QuantiSNP, which call CNVs based on logR ratio and B allele frequency. Deletions and duplications greater than 10 kb were included. Common CNVs were excluded. Association testing was performed with 1 million permutations in PLINK. Significant CNVs were confirmed with digital droplet polymerase chain reaction (ddPCR). Whole genome sequencing was performed to determine insertion location and breakpoints.

Results: Esotropia patients have similar rates and proportions of CNVs compared with controls but greater total length and average size of both deletions and duplications. Three recurrent rare duplications significantly (P = 1 {\texttimes} 10-6) increase the risk of esotropia: chromosome 2p11.2 (hg19, 2:87428677-87965359), spanning one long noncoding RNA (lncRNA) and two microRNAs (OR 14.16; 95\% confidence interval [CI] 5.4-38.1); chromosome 4p15.2 (hg19, 4:25554332-25577184), spanning one lncRNA (OR 11.1; 95\% CI 4.6-25.2); chromosome 10q11.22 (hg19, 10:47049547-47703870) spanning seven protein-coding genes, one lncRNA, and four pseudogenes (OR 8.96; 95\% CI 5.4-14.9). Overall, 114 cases (7\%) and only 28 controls (0.7\%) had one of the three rare duplications. No case nor control had more than one of these three duplications.

Conclusions: Rare CNVs are a source of genetic variation that contribute to the genetic risk for comitant esotropia, which is likely polygenic. Future research into the functional consequences of these recurrent duplications may shed light on the pathophysiology of esotropia.

}, keywords = {Case-Control Studies, DNA Copy Number Variations, Esotropia, Female, Gene Duplication, Gene Frequency, Genetic Predisposition to Disease, Genotyping Techniques, Humans, Infant, Male, Markov Chains, Polymerase Chain Reaction, Risk Factors}, issn = {1552-5783}, doi = {10.1167/iovs.61.10.22}, author = {Whitman, Mary C and Di Gioia, Silvio Alessandro and Chan, Wai-Man and Gelber, Alon and Pratt, Brandon M and Bell, Jessica L and Collins, Thomas E and Knowles, James A and Armoskus, Christopher and Pato, Michele and Pato, Carlos and Shaaban, Sherin and Staffieri, Sandra and MacKinnon, Sarah and Maconachie, Gail D E and Elder, James E and Traboulsi, Elias I and Gottlob, Irene and Mackey, David A and Hunter, David G and Engle, Elizabeth C} } @article {735, title = {Detailed genetic characteristics of an international large cohort of patients with Stargardt disease: ProgStar study report 8.}, journal = {Br J Ophthalmol}, volume = {103}, year = {2019}, month = {2019 03}, pages = {390-397}, abstract = {

BACKGROUND/AIMS: To describe the genetic characteristics of the cohort enrolled in the international multicentre progression of Stargardt disease~1 (STGD1) studies (ProgStar) and to~determine geographic differences based on the allele frequency.

METHODS: 345 participants with a clinical diagnosis of STGD1 and harbouring at least one disease-causing ABCA4 variant were enrolled from 9 centres in the USA and Europe. All variants were reviewed and analysis was performed including allele frequency in public databases and pathogenicity predictions. Participants with multiple likely pathogenic variants were classified into four national subgroups (USA, UK, France, Germany), with subsequent comparison analysis of the allele frequency for each prevalent allele.

RESULTS: 211 likely pathogenic variants were identified in the total cohort, including missense (63\%), splice site alteration (18\%), stop (9\%) and others. 50 variants were novel. Exclusively missense variants were detected in 139 (50\%) of 279 patients with multiple pathogenic variants. The three most prevalent variants of these patients with multiple pathogenic variants were p.G1961E (15\%), p.G863A (7\%)~and~c.5461-10 T>C (5\%). Subgroup analysis revealed a statistically significant difference between the four recruiting nations in the allele frequency of nine variants.

CONCLUSIONS: There is a large spectrum of ABCA4 sequence variants, including 50 novel variants, in a well-characterised cohort thereby further adding to the unique allelic heterogeneity in STGD1. Approximately half of the cohort harbours missense variants only, indicating a relatively mild phenotype of the ProgStar cohort. There are significant differences in allele frequencies between nations, although the three most prevalent variants are shared as frequent variants.

}, keywords = {Adolescent, Adult, Age of Onset, Aged, ATP-Binding Cassette Transporters, Child, Child, Preschool, Cohort Studies, Databases, Factual, DNA Mutational Analysis, Female, Gene Frequency, Genotyping Techniques, Geography, Humans, Internationality, Macular Degeneration, Male, Middle Aged, Mutation, Polymerase Chain Reaction}, issn = {1468-2079}, doi = {10.1136/bjophthalmol-2018-312064}, author = {Fujinami, Kaoru and Strauss, Rupert W and Chiang, John Pei-Wen and Audo, Isabelle S and Bernstein, Paul S and Birch, David G and Bomotti, Samantha M and Cideciyan, Artur V and Ervin, Ann-Margret and Marino, Meghan J and Sahel, Jos{\'e}-Alain and Mohand-Said, Saddek and Sunness, Janet S and Traboulsi, Elias I and West, Sheila and Wojciechowski, Robert and Zrenner, Eberhart and Michaelides, Michel and Scholl, Hendrik P N} } @article {501, title = {STRetch: detecting and discovering pathogenic short tandem repeat expansions.}, journal = {Genome Biol}, volume = {19}, year = {2018}, month = {2018 08 21}, pages = {121}, abstract = {

Short tandem repeat (STR) expansions have been identified as the causal DNA mutation in dozens of Mendelian diseases. Most existing tools for detecting STR variation with short reads do so within the read length and so are unable to detect the majority of pathogenic expansions. Here we present STRetch, a new genome-wide method to scan for STR expansions at all loci across the human genome. We demonstrate the use of STRetch for detecting STR expansions using short-read whole-genome sequencing data at known pathogenic loci as well as novel STR loci. STRetch is open source software, available from github.com/Oshlack/STRetch .

}, keywords = {Alleles, Chromosomes, Human, DNA Repeat Expansion, Genetic Loci, Genome, Human, Humans, Microsatellite Repeats, Polymerase Chain Reaction, Software}, issn = {1474-760X}, doi = {10.1186/s13059-018-1505-2}, author = {Dashnow, Harriet and Lek, Monkol and Phipson, Belinda and Halman, Andreas and Sadedin, Simon and Lonsdale, Andrew and Davis, Mark and Lamont, Phillipa and Clayton, Joshua S and Laing, Nigel G and MacArthur, Daniel G and Oshlack, Alicia} } @article {76, title = {Somatic mosaicism underlies X-linked acrogigantism syndrome in sporadic male subjects.}, journal = {Endocr Relat Cancer}, volume = {23}, year = {2016}, month = {2016 04}, pages = {221-33}, abstract = {

Somatic mosaicism has been implicated as a causative mechanism in a number of genetic and genomic disorders. X-linked acrogigantism (XLAG) syndrome is a recently characterized genomic form of pediatric gigantism due to aggressive pituitary tumors that is caused by submicroscopic chromosome Xq26.3 duplications that include GPR101 We studied XLAG syndrome patients (n= 18) to determine if somatic mosaicism contributed to the genomic pathophysiology. Eighteen subjects with XLAG syndrome caused by Xq26.3 duplications were identified using high-definition array comparative genomic hybridization (HD-aCGH). We noted that males with XLAG had a decreased log2ratio (LR) compared with expected values, suggesting potential mosaicism, whereas females showed no such decrease. Compared with familial male XLAG cases, sporadic males had more marked evidence for mosaicism, with levels of Xq26.3 duplication between 16.1 and 53.8\%. These characteristics were replicated using a novel, personalized breakpoint junction-specific quantification droplet digital polymerase chain reaction (ddPCR) technique. Using a separate ddPCR technique, we studied the feasibility of identifying XLAG syndrome cases in a distinct patient population of 64 unrelated subjects with acromegaly/gigantism, and identified one female gigantism patient who had had increased copy number variation (CNV) threshold for GPR101 that was subsequently diagnosed as having XLAG syndrome on HD-aCGH. Employing a combination of HD-aCGH and novel ddPCR approaches, we have demonstrated, for the first time, that XLAG syndrome can be caused by variable degrees of somatic mosaicism for duplications at chromosome Xq26.3. Somatic mosaicism was shown to occur in sporadic males but not in females with XLAG syndrome, although the clinical characteristics of the disease were similarly severe in both sexes.

}, keywords = {Adult, Female, Genetic Diseases, X-Linked, Gigantism, Humans, Male, Middle Aged, Mosaicism, Polymerase Chain Reaction, Syndrome, Young Adult}, issn = {1479-6821}, doi = {10.1530/ERC-16-0082}, author = {Daly, Adrian F and Yuan, Bo and Fina, Frederic and Caberg, Jean-Hubert and Trivellin, Giampaolo and Rostomyan, Liliya and de Herder, Wouter W and Naves, Luciana A and Metzger, Daniel and Cuny, Thomas and Rabl, Wolfgang and Shah, Nalini and Jaffrain-Rea, Marie-Lise and Zatelli, Maria Chiara and Faucz, Fabio R and Castermans, Emilie and Nanni-Metellus, Isabelle and Lodish, Maya and Muhammad, Ammar and Palmeira, Leonor and Potorac, Iulia and Mantovani, Giovanna and Neggers, Sebastian J and Klein, Marc and Barlier, Anne and Liu, Pengfei and Ouafik, L{\textquoteright}Houcine and Bours, Vincent and Lupski, James R and Stratakis, Constantine A and Beckers, Albert} } @article {185, title = {Absence of heterozygosity due to template switching during replicative rearrangements.}, journal = {Am J Hum Genet}, volume = {96}, year = {2015}, month = {2015 Apr 02}, pages = {555-64}, abstract = {

We investigated complex genomic rearrangements (CGRs) consisting of triplication copy-number variants (CNVs) that were accompanied by extended regions of copy-number-neutral absence of heterozygosity (AOH) in subjects with multiple congenital abnormalities. Molecular analyses provided observational evidence that in humans, post-zygotically generated CGRs can lead to regional uniparental disomy (UPD) due to template switches between homologs versus sister chromatids by using microhomology to prime DNA replication-a prediction of the replicative repair model, MMBIR. Our findings suggest that replication-based mechanisms might underlie the formation of diverse types of genomic alterations (CGRs and AOH) implicated in constitutional disorders.

}, keywords = {Base Sequence, DNA Copy Number Variations, DNA Repair, DNA Replication, Gene Rearrangement, Humans, In Situ Hybridization, Fluorescence, Loss of Heterozygosity, Models, Genetic, Molecular Sequence Data, Netherlands, Polymerase Chain Reaction, Polymorphism, Single Nucleotide, Sequence Analysis, DNA, Uniparental Disomy}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2015.01.021}, author = {Carvalho, Claudia M B and Pfundt, Rolph and King, Daniel A and Lindsay, Sarah J and Zuccherato, Luciana W and Macville, Merryn V E and Liu, Pengfei and Johnson, Diana and Stankiewicz, Pawel and Brown, Chester W and Shaw, Chad A and Hurles, Matthew E and Ira, Grzegorz and Hastings, P J and Brunner, Han G and Lupski, James R} }