Copy number variations
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OBJECTIVES: The term "copy number variation/variant" (CNV) denotes a DNA sequence with a magnitude of 1 kb at least which is differently represented among individuals based on its deletion or duplication. Since 2008, multiple studies have reported copy number variations in schizophrenia, and they seem to fill in a gap in our knowledge on the genetic background of schizophrenia. The aim of this review is to sum up the current findings related to CNVs in schizophrenia in order to facilitate further research. METHODS: We searched the PubMed computer database using the key words "schizophrenia AND CNVs" on 26th October 2011. Out of 91 obtained results, we selected the references based on their relevance. RESULTS: The CNVs at genome loci 1q21.1, 2p16.3, 3q29, 15q11.2, 15q13.3, 16p13.1 and 22q11.2 were associated with schizophrenia most frequently. The data provide evidence for low prevalent, but highly penetrant CNVs associated with schizophrenia. CNV deletions show higher penetrance than duplications. Larger CNVs often have higher penetrance than smaller CNVs. Although the vast majority of CNVs are inherited, CNVs that have newly occurred as de novo mutations have more readily been implicated in schizophrenia. De novo CNVs may be responsible for the presence of schizophrenia in only one of the two monozygotic twins, who otherwise have identical genomes. CONCLUSION: Identifying CNVs in schizophrenia can lead to changes in the treatment and genetic counselling. Our knowledge on the genetic background of neurodevelopmental disorders may also reduce stigma in schizophrenia.
- MeSH
- celogenomová asociační studie statistika a číselné údaje MeSH
- genetická predispozice k nemoci genetika MeSH
- genom lidský genetika MeSH
- lidé MeSH
- schizofrenie genetika MeSH
- variabilita počtu kopií segmentů DNA genetika MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
Transcriptome sequencing (RNA-seq) is widely used to detect gene rearrangements and quantitate gene expression in acute lymphoblastic leukemia (ALL), but its utility and accuracy in identifying copy number variations (CNVs) has not been well described. CNV information inferred from RNA-seq can be highly informative to guide disease classification and risk stratification in ALL due to the high incidence of aneuploid subtypes within this disease. Here we describe RNAseqCNV, a method to detect large scale CNVs from RNA-seq data. We used models based on normalized gene expression and minor allele frequency to classify arm level CNVs with high accuracy in ALL (99.1% overall and 98.3% for non-diploid chromosome arms, respectively), and the models were further validated with excellent performance in acute myeloid leukemia (accuracy 99.8% overall and 99.4% for non-diploid chromosome arms). RNAseqCNV outperforms alternative RNA-seq based algorithms in calling CNVs in the ALL dataset, especially in samples with a high proportion of CNVs. The CNV calls were highly concordant with DNA-based CNV results and more reliable than conventional cytogenetic-based karyotypes. RNAseqCNV provides a method to robustly identify copy number alterations in the absence of DNA-based analyses, further enhancing the utility of RNA-seq to classify ALL subtype.
- MeSH
- algoritmy MeSH
- karyotypizace MeSH
- lidé MeSH
- sekvenování transkriptomu MeSH
- variabilita počtu kopií segmentů DNA * genetika MeSH
- vysoce účinné nukleotidové sekvenování * metody MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, N.I.H., Extramural MeSH
We evaluated copy number variation (CNV) for four genes in rat strains differing in nervous system excitability. rpl13a copy number is significantly reduced in hippocampus and bone marrow in rats with a high excitability threshold and stress. The observed phenomenon may be associated with a role for rpl13a in lipid metabolism.
- MeSH
- hipokampus metabolismus fyziologie MeSH
- kortikální excitabilita genetika fyziologie MeSH
- kostní dřeň metabolismus fyziologie MeSH
- krysa rodu rattus MeSH
- nervový systém - fyziologické jevy genetika MeSH
- ribozomální proteiny genetika MeSH
- variabilita počtu kopií segmentů DNA genetika MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Danon disease (DD) is an X-linked disorder caused by mutations in the lysosomal-associated membrane protein 2 (LAMP2) gene (Xq24). DD is characterized by cognitive deficit, myopathy, and cardiomyopathy in male patients. The phenotype is variable and mitigated in females. The timely identification of de-novo LAMP2 mutated family members, many of whom are heterozygous females, remains critical for their treatment and family counseling. DD laboratory testing builds on minimally invasive quantification of the LAMP2 protein in white blood cells and characterization of the specific mutation. This integrative approach is particularly helpful when assessing suspect female heterozygotes. LAMP2 exon-copy number variations (eCNVs) were so far reported only in X-hemizygous male DD probands. In heterozygous female DD probands, the wild-type allele may hamper the identification of an eCNV even if it results in the complete abolition of LAMP2 transcription and/or translation. To document the likely underappreciated rate of occurrence and point out numerous potential pitfalls of detection of the LAMP2 eCNVs, we present the first two DD heterozygote female probands who harbor novel multi-exon LAMP2 deletions. Critical for counseling and recurrence prediction, we also highlight the need to search for somatic-germinal mosaicism in DD families.
- MeSH
- dítě MeSH
- dospělí MeSH
- exony genetika MeSH
- glykogenóza typu IIb genetika MeSH
- heterozygot MeSH
- lidé MeSH
- membránový protein 2 asociovaný s lyzozomy genetika MeSH
- mladiství MeSH
- mladý dospělý MeSH
- rodina MeSH
- rodokmen MeSH
- sekvence nukleotidů MeSH
- variabilita počtu kopií segmentů DNA genetika MeSH
- Check Tag
- dítě MeSH
- dospělí MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- kazuistiky MeSH
- práce podpořená grantem MeSH
Východiska: Přestože je bevacizumab prvním biologickým léčivem schváleným pro léčbu metastatického kolorektálního karcinomu (mCRC), neexistuje žádný zavedený DNA biomarker, který by zlepšil jeho účinnost a personalizoval léčbu. Materiál a metody: Sledováno bylo 30 pacientů s mCRC na terapii bevacizumabem (15 s dobrou odpovědí a 15 se špatnou odpovědí) z Fakultní nemocnice Olomouc. Pro analýzu variací v počtu kopií genů (copy number variation – CNV) byly použity vzorky FFPE a OncoScan FFPE Assay Kit, který zachycuje přibližně 900 nádorových genů. Výsledky: Ve skupině dobře reagujících pacientů bylo jako potenciálně významné pozitivní prediktivní nádorové biomarkery léčby bevacizumabem identifikováno 102 genů (klasifikovaných jako ATPázy, typ AAA, neuronální přenos signálu, regulace transkripce a domény typu PH superior). Ve špatně reagující skupině bylo identifikováno 74 potenciálně negativních prediktivních genů (klasifikovaných jako galektiny, signální dráha Jak-STAT, kaskáda MAPK, diferenciace a doména asociovaná s F-boxem). Závěr: V pilotní studii jsme našli slibné biomarkery variace počtu kopií odpovědi na bevacizumab v FFPE vzorcích nádorů pacientů s mCRC. Validační fáze by měla být zaměřena zejména na geny spojené s angiogenezí (AGRN, MAPK8, ARHGAP22, LGALS13, LGALS4, ZFP36 a MYC), tumorigenezí (DVL1) a proliferací tumoru (IFNL1, IFNL2, IFNL3, MAP3K10 a MAP4K1).
Background: Despite bevacizumab being the first biological agent approved for the treatment of metastatic colorectal cancer (mCRC), there is not any established DNA biomarker to improve its efficacy and personalize the treatment. Materials and methods: Thirty patients with mCRC on bevacizumab therapy (15 with a good response and 15 with a poor response) from the University Hospital Olomouc were followed. Formalin-fixed paraffin-embedded (FFPE) samples were used for copy number variation (CNV) analysis using the OncoScan FFPE Assay Kit in order to capture approx. 900 tumor genes. Results: In the group of good responding patients, 102 genes (classified as ATPases, type AAA, neuronal signal transmission, regulation of transcription, and superior domain PH type), potentially significant positive predictive tumor biomarkers of bevacizumab treatment, were found. In the poorly responding group, 74 potentially negative predictive genes (classified as galectines, Jak-STAT signalling pathway, MAPK cascade, differentiation, and F-box associated domain) were identified. Conclusion: In the pilot study, we found promising copy number variation biomarkers of bevacizumab response in FFPE samples of mCRC patients. The validation phase should be focused especially on the genes associated with angiogenesis (AGRN, MAPK8, ARHGAP22, LGALS13, LGALS4, ZFP36, and MYC), tumorigenesis (DVL1), and tumor proliferation (IFNL1, IFNL2, IFNL3, MAP3K10, and MAP4K1).
- MeSH
- bevacizumab aplikace a dávkování terapeutické užití MeSH
- kolorektální nádory * diagnóza farmakoterapie genetika patologie MeSH
- lidé MeSH
- metastázy nádorů farmakoterapie MeSH
- mutační analýza DNA metody MeSH
- nádorové biomarkery analýza genetika MeSH
- pilotní projekty MeSH
- protinádorové látky imunologicky aktivní aplikace a dávkování terapeutické užití MeSH
- variabilita počtu kopií segmentů DNA MeSH
- Check Tag
- lidé MeSH
BACKGROUND: The incidence of squamous cell carcinoma of the oral tongue (SCCOT) is increasing in people under age 40. There is an urgent need to identify prognostic markers that help identify young SCCOT patients with poor prognosis in order to select these for individualized treatment. MATERIALS AND METHODS: To identify genetic markers that can serve as prognostic markers for young SCCOT patients, we first investigated four young (≤40 years) and five elderly patients (≥50 years) using global RNA sequencing and whole-exome sequencing. Next, we combined our data with data on SCCOT from the cancer genome atlas (TCGA), giving a total of 16 young and 104 elderly, to explore the correlations between genomic variations and clinical outcomes. RESULTS: In agreement with previous studies, we found that SCCOT from young and elderly patients was transcriptomically and also genomically similar with no significant differences regarding cancer driver genes, germline predisposition genes, or the burden of somatic single nucleotide variations (SNVs). However, a disparate copy number variation (CNV) was found in young patients with distinct clinical outcome. Combined with data from TCGA, we found that the overall survival was significantly better in young patients with low-CNV (n = 5) compared to high-CNV (n = 11) burden (P = 0.044). CONCLUSIONS: Copy number variation burden is a useful single prognostic marker for SCCOT from young, but not elderly, patients. CNV burden thus holds promise to form an important contribution when selecting suitable treatment protocols for young patients with SCCOT.
- MeSH
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- míra přežití MeSH
- mladý dospělý MeSH
- nádorové biomarkery * MeSH
- nádory jazyka diagnóza genetika mortalita MeSH
- prognóza MeSH
- sekvenování exomu MeSH
- senioři MeSH
- spinocelulární karcinom diagnóza genetika mortalita MeSH
- variabilita počtu kopií segmentů DNA * MeSH
- věkové faktory MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
Some patients are susceptible to statin-associated myopathy (SAM) either because of genetic variations affecting statin uptake and metabolism, or because they predispose their carriers to muscular diseases. Among the frequent variants examined using the genome-wide association study approach, SLCO1B1 c.521T>C represents the only validated predictor of SAM in patients treated with high-dose simvastatin. Our aim was to ascertain the overall contribution of large copy-number variations (CNVs) to SAM diagnosed in 86 patients. CNVs were detected by whole genome genotyping using Illumina HumanOmni2.5 Exome BeadChips. Exome sequence data were used for validation of CNVs in SAM-related loci. In addition, we performed a specific search for CNVs in the SLCO1B region detected recently in Rotor syndrome subjects. Rare deletions possibly contributing to genetic predisposition to SAM were found in two patients: one removed EYS associated previously with SAM, the other was present in LARGE associated with congenital muscular dystrophy. Another two patients carried deletions in CYP2C19, which may predispose to clopidogrel-statin interactions. We found no common large CNVs potentially associated with SAM and no CNVs in the SLCO1B locus. Our findings suggest that large CNVs do not play a substantial role in the etiology of SAM.
- MeSH
- celogenomová asociační studie MeSH
- cytochrom P450 CYP2C19 genetika MeSH
- dospělí MeSH
- familiární hyperbilirubinemie genetika MeSH
- genetické lokusy MeSH
- genom lidský MeSH
- genotyp MeSH
- heterozygot MeSH
- kreatinkinasa krev MeSH
- lidé středního věku MeSH
- lidé MeSH
- nemoci svalů chemicky indukované genetika MeSH
- polypeptid C přenášející organické anionty genetika MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- statiny škodlivé účinky MeSH
- studie případů a kontrol MeSH
- variabilita počtu kopií segmentů DNA genetika MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
The genetic correlates of extreme impulsive violence are poorly understood, and there have been no studies that have systematically characterized a large group of affected individuals both clinically and genetically. We performed a genome-wide rare copy number variant (CNV) analysis in 281 males from four Czech prisons who met strict clinical criteria for extreme impulsive violence. Inclusion criteria included age ≥ 18 years, an ICD-10 diagnosis of Dissocial Personality Disorder, and the absence of an organic brain disorder. Participants underwent a structured psychiatric assessment to diagnose extreme impulsive violence and then provided a blood sample for genetic analysis. DNA was genotyped and CNVs were identified using Illumina HumanOmni2.5 single-nucleotide polymorphism array platform. Comparing with 10851 external population controls, we identified 828 rare CNVs (frequency ≤ 0.1% among control samples) in 264 participants. The CNVs impacted 754 genes, with 124 genes impacted more than once (2-25 times). Many of these genes are associated with autosomal dominant or X-linked disorders affecting adult behavior, cognition, learning, intelligence, specifically expressed in the brain and relevant to synapses, neurodevelopment, neurodegeneration, obesity and neuropsychiatric phenotypes. Specifically, we identified 31 CNVs of clinical relevance in 31 individuals, 59 likely clinically relevant CNVs in 49 individuals, and 17 recurrent CNVs in 65 individuals. Thus, 123 of 281 (44%) individuals had one to several rare CNVs that were indirectly or directly relevant to impulsive violence. Extreme impulsive violence is genetically heterogeneous and genomic analysis is likely required to identify, further research and specifically treat the causes in affected individuals.
- MeSH
- asociální osobnost genetika MeSH
- dospělí MeSH
- impulzivní chování * MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- násilí * MeSH
- senioři MeSH
- variabilita počtu kopií segmentů DNA * MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- mužské pohlaví MeSH
- senioři MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, N.I.H., Extramural MeSH
Mitochondrial disorders are caused by defects in mitochondrial or nuclear DNA. Although the existence of large deletions in mitochondrial DNA (mtDNA) is well known, deletions affecting whole genes are not commonly described in patients with mitochondrial disorders. Based on the results of whole-genome analyses, copy number variations (CNVs) occur frequently in the human genome and may overlap with many genes associated with clinical phenotypes. We report the discovery of two large heterozygous CNVs on 22q13.33 in two patients with mitochondrial disorders. The first patient harboured a novel point mutation c.667G>A (p.D223N) in the SCO2 gene in combination with a paternally inherited 87-kb deletion. As hypertrophic cardiomyopathy (HCMP) was not documented in the patient, this observation prompted us to compare his clinical features with all 44 reported SCO2 patients in the literature. Surprisingly, the review shows that HCMP was present in only about 50% of the SCO2 patients with non-neonatal onset. In the second patient, who had mitochondrial neurogastrointestinal encephalopathy (MNGIE), a maternally inherited 175-kb deletion and the paternally inherited point mutation c.261G>T (p.E87D) in the TYMP gene were identified.
- MeSH
- bodová mutace * MeSH
- dítě MeSH
- familiární hypertrofická kardiomyopatie diagnóza genetika MeSH
- kojenec MeSH
- lidé MeSH
- lidské chromozomy, pár 22 genetika MeSH
- mitochondriální encefalomyopatie diagnóza genetika MeSH
- mitochondriální proteiny genetika MeSH
- střevní pseudoobstrukce diagnóza genetika MeSH
- thymidinfosforylasa genetika MeSH
- transportní proteiny genetika MeSH
- variabilita počtu kopií segmentů DNA * MeSH
- Check Tag
- dítě MeSH
- kojenec MeSH
- lidé MeSH
- mužské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- kazuistiky MeSH
- práce podpořená grantem MeSH
Long transgenes are often used in mammalian genetics, e.g., to rescue mutations in large genes. In the course of experiments addressing the genetic basis of hybrid sterility caused by meiotic defects in mice bearing different alleles of Prdm9, we discovered that introduction of copy-number variation (CNV) via two independent insertions of long transgenes containing incomplete Prdm9 decreased testicular weight and epididymal sperm count. Transgenic animals displayed increased occurrence of seminiferous tubules with apoptotic cells at 18 days postpartum (dpp) corresponding to late meiotic prophase I, but not at 21 dpp. We hypothesized that long transgene insertions could cause asynapsis, but the immunocytochemical data revealed that the adult transgenic testes carried a similar percentage of asynaptic pachytene spermatocytes as the controls. These transgenic spermatocytes displayed less crossovers but similar numbers of unrepaired meiotic breaks. Despite slightly increased frequency of metaphase I spermatocytes with univalent chromosome(s) and reduced numbers of metaphase II spermatocytes, cytological studies did not reveal increased apoptosis in tubules containing the metaphase spermatocytes, but found an increased percentage of tubules carrying apoptotic spermatids. Sperm counts of subfertile animals inversely correlated with the transcription levels of the Psmb1 gene encoded within these two transgenes. The effect of the transgenes was dependent on sex and genetic background. Our results imply that the fertility of transgenic hybrid animals is not compromised by the impaired meiotic synapsis of homologous chromosomes, but can be negatively influenced by the increased expression of the introduced genes.
- MeSH
- apoptóza genetika MeSH
- dvouřetězcové zlomy DNA MeSH
- fertilita genetika MeSH
- genetické pozadí MeSH
- kontrolní body buněčného cyklu genetika MeSH
- myši MeSH
- pachytenní stadium genetika MeSH
- počet spermií MeSH
- spermatocyty metabolismus MeSH
- testis anatomie a histologie metabolismus MeSH
- transgeny * MeSH
- variabilita počtu kopií segmentů DNA * MeSH
- velikost orgánu MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- myši MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH