BACKGROUND: Whole exome sequencing (WES) and whole genome sequencing (WGS) have become standard methods in human clinical diagnostics as well as in population genomics (POPGEN). Blood-derived genomic DNA (gDNA) is routinely used in the clinical environment. Conversely, many POPGEN studies and commercial tests benefit from easy saliva sampling. Here, we evaluated the quality of variant call sets and the level of genotype concordance of single nucleotide variants (SNVs) and small insertions and deletions (indels) for WES and WGS using paired blood- and saliva-derived gDNA isolates employing genomic reference-based validated protocols. METHODS: The genomic reference standard Coriell NA12878 was repeatedly analyzed using optimized WES and WGS protocols, and data calls were compared with the truth dataset published by the Genome in a Bottle Consortium. gDNA was extracted from the paired blood and saliva samples of 10 participants and processed using the same protocols. A comparison of paired blood-saliva call sets was performed in the context of WGS and WES genomic reference-based technical validation results. RESULTS: The quality pattern of called variants obtained from genomic-reference-based technical replicates correlates with data calls of paired blood-saliva-derived samples in all levels of tested examinations despite a higher rate of non-human contamination found in the saliva samples. The F1 score of 10 blood-to-saliva-derived comparisons ranged between 0.8030-0.9998 for SNVs and between 0.8883-0.9991 for small-indels in the case of the WGS protocol, and between 0.8643-0.999 for SNVs and between 0.7781-1.000 for small-indels in the case of the WES protocol. CONCLUSION: Saliva may be considered an equivalent material to blood for genetic analysis for both WGS and WES under strict protocol conditions. The accuracy of sequencing metrics and variant-detection accuracy is not affected by choosing saliva as the gDNA source instead of blood but much more significantly by the genomic context, variant types, and the sequencing technology used.
- MeSH
- DNA genetika MeSH
- exom MeSH
- genom lidský MeSH
- genomika MeSH
- lidé MeSH
- metagenomika * MeSH
- sekvenování celého genomu MeSH
- sekvenování exomu MeSH
- sliny * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
BACKGROUND: Neurodevelopmental disorders (NDDs) and/or associated multiple congenital abnormalities (MCAs) represent a genetically heterogeneous group of conditions with an adverse prognosis for the quality of intellectual and social abilities and common daily functioning. The rapid development of exome sequencing (ES) techniques, together with trio-based analysis, nowadays leads to up to 50% diagnostic yield. Therefore, it is considered as the state-of-the-art approach in these diagnoses. RESULTS: In our study, we present the results of ES in a cohort of 85 families with 90 children with severe NDDs and MCAs. The interconnection of the in-house bioinformatic pipeline and a unique algorithm for variant prioritization resulted in a diagnostic yield of up to 48.9% (44/90), including rare and novel causative variants (41/90) and intragenic copy-number variations (CNVs) (3/90). Of the total number of 47 causative variants, 53.2% (25/47) were novel, highlighting the clinical benefit of ES for unexplained NDDs. Moreover, trio-based ES was verified as a reliable tool for the detection of rare CNVs, ranging from intragenic exon deletions (GRIN2A, ZC4H2 genes) to a 6-Mb duplication. The functional analysis using PANTHER Gene Ontology confirmed the involvement of genes with causative variants in a wide spectrum of developmental processes and molecular pathways, which form essential structural and functional components of the central nervous system. CONCLUSION: Taken together, we present one of the first ES studies of this scale from the central European region. Based on the high diagnostic yield for paediatric NDDs in this study, 48.9%, we confirm trio-based ES as an effective and reliable first-tier diagnostic test in the genetic evaluation of children with NDDs.
Nejčastější primární nádor jater u dětí je hepatoblastom. Jednou z příčin vzniku může být genetická predispozice. Cca 14 % hepatoblastomů vyrůstá na podkladě familiární adenomatózní polypózy. Popisujeme kazuistiku rodiny s genetickou predispozicí - ze 4 dětí 3 byly pozitivně testovány na genetice s FAP, u všech 3 dětí se rozvinul hepatoblastom v útlém dětském věku. Prezentovaná rodina podporuje genetický skrínink dětí z FAP pozitivní rodiny ve věku 6 měsíců až 1 rok s následnou dispenzarizací.
Hepatoblastoma is the most common primary tumour of the liver in children. Genetic predisposition may be one of the causative factors. Approximately 14 % of hepatoblastomas occur as a result of familial adenomatous polyposis. We describe a case report of a family with a genetic predisposition - three out of four children tested positive for FAP, and the three children developed hepatoblastoma at a very early age. The presented family supports genetic screening of children from a FAP-positive family at the age of 6 months to 1 year with subsequent surveillance.
- MeSH
- anamnéza MeSH
- familiární adenomatózní polypóza * komplikace patologie MeSH
- genetická predispozice k nemoci MeSH
- hepatoblastom * etiologie genetika patofyziologie MeSH
- lidé MeSH
- nádory etiologie klasifikace MeSH
- předškolní dítě MeSH
- riziko MeSH
- rodokmen MeSH
- sekvenování exomu MeSH
- sourozenci MeSH
- Check Tag
- lidé MeSH
- předškolní dítě MeSH
- ženské pohlaví MeSH
- Publikační typ
- kazuistiky MeSH
OBJECTIVE: Developmental and epileptic encephalopathies (DEEs) are a group of severe, early-onset epilepsies characterised by refractory seizures, developmental delay, or regression and generally poor prognosis. DEE are now known to have an identifiable molecular genetic basis and are usually examined using a gene panel. However, for many patients, the genetic cause has still not been identified. The aims of this study were to identify causal variants for DEE in patients for whom the previous examination with a gene panel did not determine their genetic diagnosis. It also aims for a detailed description and broadening of the phenotypic spectrum of several rare DEEs. METHODS: In the last five years (2015-2020), 141 patients from all over the Czech Republic were referred to our department for genetic testing in association with their diagnosis of epilepsy. All patients underwent custom-designed gene panel testing prior to enrolment into the study, and their results were inconclusive. We opted for whole exome sequencing (WES) to identify the cause of their disorder. If a causal or potentially causal variant was identified, we performed a detailed clinical evaluation and phenotype-genotype correlation study to better describe the specific rare subtypes. RESULTS: Explanatory causative variants were detected in 20 patients (14%), likely pathogenic variants that explain the epilepsy in 5 patients (3.5%) and likely pathogenic variants that do not fully explain the epilepsy in 11 patients (7.5%), and variants in candidate genes in 4 patients (3%). Variants were mostly de novo 29/40 (72.5%). SIGNIFICANCE: WES enables us to identify the cause of the disease in additional patients, even after gene panel testing. It is very important to perform a WES in DEE patients as soon as possible, since it will spare the patients and their families many years of a diagnostic odyssey. In particular, patients with rare epilepsies might significantly benefit from this approach, and we propose using WES as a new standard in the diagnosis of DEE instead of targeted gene panel testing.
- MeSH
- epilepsie generalizovaná * genetika MeSH
- epilepsie * diagnóza genetika MeSH
- fenotyp MeSH
- genetické asociační studie MeSH
- genetické testování MeSH
- lidé MeSH
- sekvenování exomu MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Kostní dysplazie jsou širokou, heterogenní skupinou chorob. Thanatoforická dysplazie patří mezi nejčastější letální kostní dysplazie. Základem diagnostiky je kvalitní ultrazvukové vyšetření ve II. trimestru a nejnovější metody genetického testování vč. vyšetření klinického exomu. Znalost správné diagnózy je klíčová pro budoucnost plodu i páru.
Bone dysplasias are a broad, heterogeneous group of diseases. Thanatophoric dysplasia is a rare bone dysplasia, but it is the most common lethal skeletal dysplasias. The major role in diagnostics plays a high-quality ultrasound examination in the 2nd trimester and the latest methods of genetic testing, including clinical exome testing. Knowing the correct diagnosis is crucial for the future of the fetus and the couple.
- MeSH
- dospělí MeSH
- indukovaný potrat MeSH
- lidé MeSH
- nemoci plodu diagnostické zobrazování genetika patologie MeSH
- progrese nemoci MeSH
- sekvenování exomu * MeSH
- těhotenství MeSH
- thanatoforní dysplazie * diagnostické zobrazování genetika patologie MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- těhotenství MeSH
- ženské pohlaví MeSH
- Publikační typ
- kazuistiky MeSH
- MeSH
- dilatační kardiomyopatie genetika MeSH
- genetické testování metody MeSH
- hypertrofická kardiomyopatie genetika MeSH
- lidé MeSH
- restriktivní kardiomyopatie genetika MeSH
- sekvenování exomu metody MeSH
- srdeční selhání * genetika MeSH
- vysoce účinné nukleotidové sekvenování metody MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- přehledy MeSH
BACKGROUND AND AIM: Gene defects contribute to the aetiology of intrahepatic cholestasis. We aimed to explore the outcome of whole-exome sequencing (WES) in a cohort of 51 patients with this diagnosis. PATIENTS AND METHODS: Both paediatric (n = 33) and adult (n = 18) patients with cholestatic liver disease of unknown aetiology were eligible. WES was used for reassessment of 34 patients (23 children) without diagnostic genotypes in ABCB11, ATP8B1, ABCB4 or JAG1 demonstrable by previous Sanger sequencing, and for primary assessment of additional 17 patients (10 children). Nasopharyngeal swab mRNA was analysed to address variant pathogenicity in two families. RESULTS: WES revealed biallelic variation in 3 ciliopathy genes (PKHD1, TMEM67 and IFT172) in 4 clinically unrelated index subjects (3 children and 1 adult), heterozygosity for a known variant in PPOX in one adult index subject, and homozygosity for an unreported splice-site variation in F11R in one child. Whereas phenotypes of the index patients with mutated PKHD1, TMEM67, and PPOX corresponded with those elsewhere reported, how F11R variation underlies liver disease remains unclear. Two unrelated patients harboured different novel biallelic variants in IFT172, a gene implicated in short-rib thoracic dysplasia 10 and Bardet-Biedl syndrome 20. One patient, a homozygote for IFT172 rs780205001 c.167A>C p.(Lys56Thr) born to first cousins, had liver disease, interpreted on biopsy aged 4y as glycogen storage disease, followed by adult-onset nephronophthisis at 25y. The other, a compound heterozygote for novel frameshift variant IFT172 NM_015662.3 c.2070del p.(Met690Ilefs*11) and 2 syntenic missense variants IFT172 rs776310391 c.157T>A p.(Phe53Ile) and rs746462745 c.164C>G p.(Thr55Ser), had a severe 8mo cholestatic episode in early infancy, with persisting hyperbilirubinemia and fibrosis on imaging studies at 17y. No patient had skeletal malformations. CONCLUSION: Our findings suggest association of IFT172 variants with non-syndromic cholestatic liver disease.
- MeSH
- adaptorové proteiny signální transdukční genetika MeSH
- cholestáza * genetika MeSH
- cytoskeletální proteiny genetika MeSH
- flavoproteiny genetika MeSH
- genotyp MeSH
- intrahepatální cholestáza * genetika diagnóza MeSH
- lidé MeSH
- mitochondriální proteiny genetika MeSH
- mutace MeSH
- protoporfyrinogenoxidasa genetika MeSH
- sekvenování exomu MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
PURPOSE: Analysis of somatic variant profiles in retrospectively collected pairs of primary tumors and synchronous liver metastases from surgically treated patients with colorectal carcinomas. Mutational profiles were compared between groups of patients stratified by response to chemotherapy and survival. PATIENTS AND METHODS: The study used whole-exome sequencing of tumor sample pairs from 20 patients diagnosed and treated at a single center. The Cancer Genome Atlas COAD-READ data set (n = 380) was used for validation in silico, where possible. RESULTS: The most frequently altered oncodrivers were APC (55% in primaries and 60% in metastases), TP53 (50/45), TRIP11 (30/5), FAT4 (20/25), and KRAS (15/25). Harboring variants with a high or moderate predicted functional effect in KRAS in primary tumors was significantly associated with poor relapse-free survival in both our sample set and the validation data set. We found a number of additional prognostic associations, including mutational load, alterations in individual genes, oncodriver pathways, and single base substitution (SBS) signatures in primary tissues, which were not confirmed by validation. Altered ATM, DNAH11, and MUC5AC, or a higher share of SBS24 signature in metastases seemed to represent poor prognostic factors, but because of a lack of suitable validation data sets, these results must be treated with extreme caution. No gene or profile was significantly associated with response to chemotherapy. CONCLUSION: Taken together, we report subtle differences in exome mutational profiles between paired primary tumors and synchronous liver metastases and a distinct prognostic relevance of KRAS in primary tumors. Although the general scarcity of primary tumor-synchronous metastasis sample pairs with high-quality clinical data makes robust validation difficult, this study provides potentially valuable data for utilization in precision oncology and could serve as a springboard for larger studies.
- MeSH
- individualizovaná medicína MeSH
- kolorektální nádory * farmakoterapie genetika MeSH
- lidé MeSH
- lokální recidiva nádoru MeSH
- nádory jater * farmakoterapie genetika MeSH
- prognóza MeSH
- protoonkogenní proteiny p21(ras) genetika MeSH
- retrospektivní studie MeSH
- sekvenování exomu MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Pathogenic variants affecting the BLM gene are responsible for the manifestation of extremely rare cancer‐predisposing Bloom syndrome. The present study reports on a case of an infant with a congenital hypotrophy, short stature and abnormal facial appearance. Initially she was examined using a routine molecular diagnostic algorithm, including the cytogenetic analysis of her karyotype, microarray analysis and methylation‐specific MLPA, however, she remained undiagnosed on a molecular level. Therefore, she and her parents were enrolled in the project of trio‐based exome sequencing (ES) using Human Core Exome kit. She was revealed as a carrier of an extremely rare combination of causative sequence variants altering the BLM gene (NM_000057.4), c.1642C>T and c.2207_2212delinsTAGATTC in the compound heterozygosity, resulting in a diagnosis of Bloom syndrome. Simultaneously, a mosaic loss of heterozygosity of chromosome 11p was detected and then confirmed as a borderline imprinting center 1 hypermethylation on chromosome 11p15. The diagnosis of Bloom syndrome and mosaic copy‐number neutral loss of heterozygosity of chromosome 11p increases a lifetime risk to develop any types of malignancy. This case demonstrates the trio‐based ES as a complex approach for the molecular diagnostics of rare pediatric diseases.
- MeSH
- Bloomův syndrom * diagnóza genetika patologie MeSH
- dítě MeSH
- heterozygot MeSH
- kojenec MeSH
- lidé MeSH
- lidský chromozom Y MeSH
- mozaicismus MeSH
- sekvenování exomu MeSH
- Check Tag
- dítě MeSH
- kojenec MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- kazuistiky MeSH
INTRODUCTION: Cerebral palsy (CP) is a group of permanent disorders attributed to non-progressive disturbances that occurred in the developing fetal or infant brain. Cerebral palsy-like (CP-like) disorders may clinically resemble CP but do not fulfill CP criteria and have often a progressive course and/or neurodevelopmental regression. To assess which patients with dystonic CP and dystonic CP-like disorder should undergo Whole Exome Sequencing (WES), we compared the rate of likely causative variants in individuals regarding their clinical picture, co-morbidities, and environmental risk factors. METHOD: Individuals with early onset neurodevelopmental disorder (ND) manifesting with dystonia as a core feature were divided into CP or CP-like cohorts based on their clinical picture and disease course. Detailed clinical picture, co-morbidities, and environmental risk factors including prematurity, asphyxia, SIRS, IRDS, and cerebral bleeding were evaluated. RESULTS: A total of 122 patients were included and divided into the CP group with 70 subjects (30 males; mean age 18y5m±16y6m, mean GMFCS score 3.3 ± 1.4), and the CP-like group with 52 subjects (29 males; mean age 17y7m±1y,6 m, mean GMFCS score 2,6 ± 1,5). The WES-based diagnosis was present in 19 (27.1%) CP patients and 30 CP-like patients (57.7%) with genetic conditions overlap in both groups. We found significant differences in diagnostic rate in CP individuals with vs. without risk factors (13.9% vs. 43.3%); Fisher's exact p = 0.0065. We did not observe the same tendency in CP-like (45.5% vs 58.5%); Fisher's exact p = 0.5. CONCLUSION: WES is a useful diagnostic method for patients with dystonic ND, regardless of their presentation as a CP or CP-like phenotype.
- MeSH
- dystonické poruchy * genetika komplikace MeSH
- dystonie * genetika komplikace MeSH
- lidé MeSH
- mozek MeSH
- mozková obrna * genetika MeSH
- sekvenování exomu MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
