Genetic testing for pathogenic COL4A3-5 variants is usually undertaken to investigate the cause of persistent hematuria, especially with a family history of hematuria or kidney function impairment. Alport syndrome experts now advocate genetic testing for persistent hematuria, even when a heterozygous pathogenic COL4A3 or COL4A4 is suspected, and cascade testing of their first-degree family members because of their risk of impaired kidney function. The experts recommend too that COL4A3 or COL4A4 heterozygotes do not act as kidney donors. Testing for variants in the COL4A3-COL4A5 genes should also be performed for persistent proteinuria and steroid-resistant nephrotic syndrome due to suspected inherited FSGS and for familial IgA glomerulonephritis and kidney failure of unknown cause.
- Klíčová slova
- Alport syndrome, COL4A3, COL4A4, COL4A5, FSGS, collagen IV, digenic Alport syndrome, genetic testing, kidney cysts, thin basement membrane nephropathy,
- MeSH
- autoantigeny genetika MeSH
- dědičná nefritida diagnóza genetika terapie MeSH
- genetické testování normy MeSH
- kolagen typu IV genetika MeSH
- lidé MeSH
- směrnice pro lékařskou praxi jako téma MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- autoantigeny MeSH
- COL4A5 protein, human MeSH Prohlížeč
- kolagen typu IV MeSH
- type IV collagen alpha3 chain MeSH Prohlížeč
The recent Chandos House meeting of the Alport Variant Collaborative extended the indications for screening for pathogenic variants in the COL4A5, COL4A3 and COL4A4 genes beyond the classical Alport phenotype (haematuria, renal failure; family history of haematuria or renal failure) to include persistent proteinuria, steroid-resistant nephrotic syndrome, focal and segmental glomerulosclerosis (FSGS), familial IgA glomerulonephritis and end-stage kidney failure without an obvious cause. The meeting refined the ACMG criteria for variant assessment for the Alport genes (COL4A3-5). It identified 'mutational hotspots' (PM1) in the collagen IV α5, α3 and α4 chains including position 1 Glycine residues in the Gly-X-Y repeats in the intermediate collagenous domains; and Cysteine residues in the carboxy non-collagenous domain (PP3). It considered that 'well-established' functional assays (PS3, BS3) were still mainly research tools but sequencing and minigene assays were commonly used to confirm splicing variants. It was not possible to define the Minor Allele Frequency (MAF) threshold above which variants were considered Benign (BA1, BS1), because of the different modes of inheritances of Alport syndrome, and the occurrence of hypomorphic variants (often Glycine adjacent to a non-collagenous interruption) and local founder effects. Heterozygous COL4A3 and COL4A4 variants were common 'incidental' findings also present in normal reference databases. The recognition and interpretation of hypomorphic variants in the COL4A3-COL4A5 genes remains a challenge.
- MeSH
- autoantigeny genetika MeSH
- dědičná nefritida diagnóza genetika MeSH
- fenotyp MeSH
- genetické testování metody normy MeSH
- kolagen typu IV genetika MeSH
- konsensus * MeSH
- lidé MeSH
- směrnice pro lékařskou praxi jako téma * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- autoantigeny MeSH
- COL4A4 protein, human MeSH Prohlížeč
- COL4A5 protein, human MeSH Prohlížeč
- kolagen typu IV MeSH
- type IV collagen alpha3 chain MeSH Prohlížeč
BACKGROUND: Family genetic testing of patients newly diagnosed with a rare genetic disease can improve early diagnosis of family members, allowing patients to receive disease-specific therapies when available. Fabry disease, an X-linked lysosomal storage disorder caused by pathogenic variants in GLA, can lead to end-stage renal disease, cardiac arrhythmias, and stroke. Diagnostic delays are common due to the rarity of the disease and non-specificity of early symptoms. Newborn screening and screening of at-risk populations, (e.g., patients with hypertrophic cardiomyopathy or undiagnosed nephropathies) can identify individuals with Fabry disease. Subsequent cascade genotyping of family members may disclose a greater number of affected individuals, often at younger age than they would have been diagnosed otherwise. METHODS: We conducted a literature search to identify all published data on family genetic testing for Fabry disease, and discussed these data, experts' own experiences with family genetic testing, and the barriers to this type of screening that are present in their respective countries. RESULTS: There are potential barriers that make implementation of family genetic testing challenging in some countries. These include associated costs and low awareness of its importance, and cultural and societal issues. Regionally, there are barriers associated with population educational levels, national geography and infrastructures, and a lack of medical geneticists. CONCLUSION: In this review, the worldwide experience of an international group of experts of Fabry disease highlights the issues faced in the family genetic testing of patients affected with rare genetic diseases.
- Klíčová slova
- Fabry disease, at-risk populations screening, cascade genotyping, early diagnosis, family genetic testing, pedigree drawing, rare disease,
- MeSH
- Fabryho nemoc diagnóza genetika MeSH
- genetické testování metody normy MeSH
- lidé MeSH
- rodokmen MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
BACKGROUND: Targeted sequencing using oncopanels requires comprehensive assessments of accuracy and detection sensitivity to ensure analytical validity. By employing reference materials characterized by the U.S. Food and Drug Administration-led SEquence Quality Control project phase2 (SEQC2) effort, we perform a cross-platform multi-lab evaluation of eight Pan-Cancer panels to assess best practices for oncopanel sequencing. RESULTS: All panels demonstrate high sensitivity across targeted high-confidence coding regions and variant types for the variants previously verified to have variant allele frequency (VAF) in the 5-20% range. Sensitivity is reduced by utilizing VAF thresholds due to inherent variability in VAF measurements. Enforcing a VAF threshold for reporting has a positive impact on reducing false positive calls. Importantly, the false positive rate is found to be significantly higher outside the high-confidence coding regions, resulting in lower reproducibility. Thus, region restriction and VAF thresholds lead to low relative technical variability in estimating promising biomarkers and tumor mutational burden. CONCLUSION: This comprehensive study provides actionable guidelines for oncopanel sequencing and clear evidence that supports a simplified approach to assess the analytical performance of oncopanels. It will facilitate the rapid implementation, validation, and quality control of oncopanels in clinical use.
- Klíčová slova
- Analytical performance, Molecular diagnostics, Oncopanel sequencing, Precision medicine, Reproducibility, Target enrichment,
- MeSH
- diagnostické techniky molekulární metody normy MeSH
- genetické testování metody normy MeSH
- genomika metody normy MeSH
- jednonukleotidový polymorfismus MeSH
- lidé MeSH
- mutace MeSH
- nádorové biomarkery * MeSH
- nádory diagnóza genetika MeSH
- onkogeny * MeSH
- reprodukovatelnost výsledků MeSH
- senzitivita a specificita MeSH
- variabilita počtu kopií segmentů DNA MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, N.I.H., Intramural MeSH
- Research Support, U.S. Gov't, P.H.S. MeSH
- Názvy látek
- nádorové biomarkery * MeSH
BACKGROUND: Oncopanel genomic testing, which identifies important somatic variants, is increasingly common in medical practice and especially in clinical trials. Currently, there is a paucity of reliable genomic reference samples having a suitably large number of pre-identified variants for properly assessing oncopanel assay analytical quality and performance. The FDA-led Sequencing and Quality Control Phase 2 (SEQC2) consortium analyze ten diverse cancer cell lines individually and their pool, termed Sample A, to develop a reference sample with suitably large numbers of coding positions with known (variant) positives and negatives for properly evaluating oncopanel analytical performance. RESULTS: In reference Sample A, we identify more than 40,000 variants down to 1% allele frequency with more than 25,000 variants having less than 20% allele frequency with 1653 variants in COSMIC-related genes. This is 5-100× more than existing commercially available samples. We also identify an unprecedented number of negative positions in coding regions, allowing statistical rigor in assessing limit-of-detection, sensitivity, and precision. Over 300 loci are randomly selected and independently verified via droplet digital PCR with 100% concordance. Agilent normal reference Sample B can be admixed with Sample A to create new samples with a similar number of known variants at much lower allele frequency than what exists in Sample A natively, including known variants having allele frequency of 0.02%, a range suitable for assessing liquid biopsy panels. CONCLUSION: These new reference samples and their admixtures provide superior capability for performing oncopanel quality control, analytical accuracy, and validation for small to large oncopanels and liquid biopsy assays.
- MeSH
- alely * MeSH
- frekvence genu * MeSH
- genetická heterogenita MeSH
- genetická variace * MeSH
- genetické testování metody normy MeSH
- genomika metody normy MeSH
- lidé MeSH
- nádorové biomarkery * MeSH
- nádorové buněčné linie MeSH
- nádory diagnóza genetika MeSH
- průběh práce MeSH
- variabilita počtu kopií segmentů DNA MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- nádorové biomarkery * MeSH
If genome sequencing is performed in health care, in theory the opportunity arises to take a further look at the data: opportunistic genomic screening (OGS). The European Society of Human Genetics (ESHG) in 2013 recommended that genome analysis should be restricted to the original health problem at least for the time being. Other organizations have argued that 'actionable' genetic variants should or could be reported (including American College of Medical Genetics and Genomics, French Society of Predictive and Personalized Medicine, Genomics England). They argue that the opportunity should be used to routinely and systematically look for secondary findings-so-called opportunistic screening. From a normative perspective, the distinguishing characteristic of screening is not so much its context (whether public health or health care), but the lack of an indication for having this specific test or investigation in those to whom screening is offered. Screening entails a more precarious benefits-to-risks balance. The ESHG continues to recommend a cautious approach to opportunistic screening. Proportionality and autonomy must be guaranteed, and in collectively funded health-care systems the potential benefits must be balanced against health care expenditures. With regard to genome sequencing in pediatrics, ESHG argues that it is premature to look for later-onset conditions in children. Counseling should be offered and informed consent is and should be a central ethical norm. Depending on developing evidence on penetrance, actionability, and available resources, OGS pilots may be justified to generate data for a future, informed, comparative analysis of OGS and its main alternatives, such as cascade testing.
- MeSH
- genetické testování etika normy MeSH
- genetika člověka etika organizace a řízení normy MeSH
- lidé MeSH
- směrnice pro lékařskou praxi jako téma * MeSH
- společnosti lékařské normy MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Evropa MeSH
The RASopathies are a group of clinically and genetically heterogeneous developmental disorders caused by dysregulation of the RAS/MAPK signalling pathway. Variants in several components and regulators of this pathway have been identified as the pathogenetic cause. In 2015, missense variants in A2ML1 were reported in three unrelated families with clinical diagnosis of Noonan syndrome (NS) and a zebrafish model was presented showing heart and craniofacial defects similar to those caused by a NS-associated Shp2 variant. However, a causal role of A2ML1 variants in NS has not been confirmed since. Herein, we report on 15 individuals who underwent screening of RASopathy-associated genes and were found to carry rare variants in A2ML1, including variants previously proposed to be causative for NS. In cases where parental DNA was available, the respective A2ML1 variant was found to be inherited from an unaffected parent. Seven index patients carrying an A2ML1 variant presented with an alternate disease-causing genetic aberration. These findings underscore that current evidence is insufficient to support a causal relation between variants in A2ML1 and NS, questioning the inclusion of A2ML1 screening in diagnostic RASopathy testing.
- MeSH
- alfa-makroglobuliny genetika MeSH
- fenotyp * MeSH
- genetické testování normy MeSH
- lidé MeSH
- mutace * MeSH
- Noonanové syndrom genetika patologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- A2ML1 protein, human MeSH Prohlížeč
- alfa-makroglobuliny MeSH
Newborn screening (NBS) is an important part of public healthcare systems in many countries. The provision of information to parents about NBS is now recognised as an integral part of the screening process. Informing parents on all aspects of screening helps to achieve the benefits, promote trust and foster support for NBS. Therefore, policies and guidelines should exist to govern how the information about NBS is provided to parents, taking into account evidence-based best practices. The purpose of our survey was to explore whether any legally binding provisions, guidelines or recommendations existed pertaining to the provision of information about NBS to parents across Europe. Questions were designed to determine the regulatory process of when, by whom and how parents should be informed about screening. Twenty-seven countries participated in the survey. The results indicated that most countries had some sort of legal framework or guidelines for the provision of information to parents. However, only 37% indicated that the provision of information was required prenatally. The majority of countries were verbally informing parents with the aid of written materials postnatally, just prior to sample collection. Information was provided by a neonatologist, midwife or nurse. A website dedicated to NBS was available for 67% of countries and 89% had written materials about NBS for parents. The survey showed that there is a lack of harmonisation among European countries in the provision of information about NBS and emphasised the need for more comprehensive guidelines at the European level.
- MeSH
- Evropská unie MeSH
- genetické testování zákonodárství a právo normy MeSH
- lidé MeSH
- novorozenec MeSH
- novorozenecký screening zákonodárství a právo normy MeSH
- organizační politika * MeSH
- průzkumy a dotazníky MeSH
- rodiče * MeSH
- směrnice pro lékařskou praxi jako téma MeSH
- zveřejnění zákonodárství a právo normy MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- novorozenec MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Oncogenic gene fusions represent attractive targets for therapy of cancer. However, the frequency of actionable genomic rearrangements in colorectal cancer (CRC) is very low, and universal screening for these alterations seems to be impractical and costly. To address this problem, several large scale studies retrospectivelly showed that CRC with gene fusions are highly enriched in groups of tumors defined by MLH1 DNA mismatch repair protein deficiency (MLH1d), and hypermethylation of MLH1 promoter (MLH1ph), and/or the presence of microsatellite instability, and BRAF/KRAS wild-type status (BRAFwt/KRASwt). In this study, we used targeted next generation sequencing (NGS) to explore the occurence of potentially therapeutically targetable gene fusions in an unselected series of BRAFwt/KRASwt CRC cases that displayed MLH1d/MLH1ph. From the initially identified group of 173 MLH1d CRC cases, 141 cases (81.5%) displayed MLH1ph. BRAFwt/RASwt genotype was confirmed in 23 of 141 (~16%) of MLH1d/MLH1ph cases. Targeted NGS of these 23 cases identified oncogenic gene fusions in nine patients (39.1%; CI95: 20.5%-61.2%). Detected fusions involved NTRK (four cases), ALK (two cases), and BRAF genes (three cases). As a secondary outcome of NGS testing, we identified PIK3K-AKT-mTOR pathway alterations in two CRC cases, which displayed PIK3CA mutation. Altogether, 11 of 23 (~48%) MLH1d/MLH1ph/BRAFwt/RASwt tumors showed genetic alterations that could induce resistance to anti-EGFR therapy. Our study confirms that targeted NGS of MLH1d/MLH1ph and BRAFwt/RASwt CRCs could be a cost-effective strategy in detecting patients with potentially druggable oncogenic kinase fusions.
- Klíčová slova
- ALK, BRAF, NTRK, colorectal cancer, gene fusions,
- MeSH
- adenokarcinom diagnóza genetika MeSH
- anaplastická lymfomová kináza genetika MeSH
- dospělí MeSH
- fúzní onkogenní proteiny genetika MeSH
- genetické testování metody normy MeSH
- kolorektální nádory diagnóza genetika MeSH
- lidé středního věku MeSH
- lidé MeSH
- metylace DNA MeSH
- MutL homolog 1 nedostatek genetika MeSH
- promotorové oblasti (genetika) MeSH
- protoonkogenní proteiny B-Raf genetika MeSH
- protoonkogenní proteiny p21(ras) genetika MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- tyrosinkinasové receptory genetika MeSH
- vysoce účinné nukleotidové sekvenování metody normy 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
- práce podpořená grantem MeSH
- Názvy látek
- ALK protein, human MeSH Prohlížeč
- anaplastická lymfomová kináza MeSH
- BRAF protein, human MeSH Prohlížeč
- fúzní onkogenní proteiny MeSH
- KRAS protein, human MeSH Prohlížeč
- MLH1 protein, human MeSH Prohlížeč
- MutL homolog 1 MeSH
- protoonkogenní proteiny B-Raf MeSH
- protoonkogenní proteiny p21(ras) MeSH
- tyrosinkinasové receptory MeSH
Adult-onset neuronal ceroid lipofuscinoses (ANCL, Kufs disease) are rare hereditary neuropsychiatric disorders characterized by intralysosomal accumulation of ceroid in tissues. The ceroid accumulation primarily affects the brain, leading to neuronal loss and progressive neurodegeneration. Although several causative genes have been identified (DNAJC5, CLN6, CTSF, GRN, CLN1, CLN5, ATP13A2), the genetic underpinnings of ANCL in some families remain unknown. Here we report one family with autosomal dominant (AD) Kufs disease caused by a 30 bp in-frame duplication in DNAJC5, encoding the cysteine-string protein alpha (CSPα). This variant leads to a duplication of the central core motif of the cysteine-string domain of CSPα and affects palmitoylation-dependent CSPα sorting in cultured neuronal cells similarly to two previously described CSPα variants, p.(Leu115Arg) and p.(Leu116del). Interestingly, the duplication was not detected initially by standard Sanger sequencing due to a preferential PCR amplification of the shorter wild-type allele and allelic dropout of the mutated DNAJC5 allele. It was also missed by subsequent whole-exome sequencing (WES). Its identification was facilitated by reanalysis of original WES data and modification of the PCR and Sanger sequencing protocols. Independently occurring variants in the genomic sequence of DNAJC5 encoding the cysteine-string domain of CSPα suggest that this region may be more prone to DNA replication errors and that insertions or duplications within this domain should be considered in unsolved ANCL cases.
- MeSH
- buněčné linie MeSH
- dospělí MeSH
- duplikace genu * MeSH
- falešně negativní reakce MeSH
- genetické testování normy MeSH
- lidé středního věku MeSH
- lidé MeSH
- membránové proteiny genetika metabolismus MeSH
- myši MeSH
- neuronální ceroidlipofuscinózy genetika patologie MeSH
- neurony metabolismus MeSH
- posttranslační úpravy proteinů MeSH
- proteiny tepelného šoku HSP40 genetika metabolismus MeSH
- sekvenování celého genomu normy MeSH
- transport proteinů MeSH
- zvířata MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- myši MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- cysteine string protein MeSH Prohlížeč
- membránové proteiny MeSH
- proteiny tepelného šoku HSP40 MeSH