Genetic counseling in direct-to-consumer exome sequencing: a case report.
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ABSTRACT:
SUBMITTER: van den Berg S
PROVIDER: S-EPMC4156788 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:The discovery of rare genetic variation through different gene sequencing methods is a very challenging subject in the field of human genetics. A case of a 1-year-old boy with metabolic acidosis and hypokalemia, a small penis, growth retardation, and G-6PD deficiency was reported. Since the clinical symptoms are complex and seem uncorrelated, the authors hypothesized that the child had chromosome or gene problems, and exome sequencing (ES) was applied to samples from him and his parents. Three main locus mutations in three genes were found in the proband, including SLC4A1, FGFR1, and G6PD genes. A missense mutation (c.1766G>T, p.R589 L) was found in exon 14 of SLC4A1 gene, which was a de novo mutation. Another missense mutation (c.1028 A>G, p.H343R) was found in exon 9 of FGFR1 gene, which was also a de novo mutation. These findings further demonstrate the utility of ES in the diagnosis of rare diseases.
| S-EPMC8567987 | biostudies-literature
Project description:BackgroundDespite advances in routine prenatal cytogenetic testing, most anomalous fetuses remain without a genetic diagnosis. Exome sequencing (ES) is a molecular technique that identifies sequence variants across protein-coding regions and is now increasingly used in clinical practice. Fetal phenotypes differ from postnatal and, therefore, prenatal ES interpretation requires a large amount of data deriving from prenatal testing. The aim of our study was to present initial results of the implementation of ES to prenatal diagnosis in Polish patients and to discuss its possible clinical impact on genetic counseling.MethodsIn this study we performed a retrospective review of all fetal samples referred to our laboratory for ES from cooperating centers between January 2017 and June 2021.ResultsDuring the study period 122 fetuses were subjected to ES at our institution. There were 52 abnormal ES results: 31 in the group of fetuses with a single organ system anomaly and 21 in the group of fetuses with multisystem anomalies. The difference between groups was not statistically significant. There were 57 different pathogenic or likely pathogenic variants reported in 33 different genes. The most common were missense variants. In 17 cases the molecular diagnosis had an actual clinical impact on subsequent pregnancies or other family members.ConclusionsExome sequencing increases the detection rate in fetuses with structural anomalies and improves genetic counseling for both the affected couple and their relatives.
| S-EPMC9140952 | biostudies-literature
Project description:The yield of genetic prenatal diagnosis has been notably improved by introducing whole genome chromosomal microarray (CMA) and prenatal exome sequencing (pES). However, together with increased numbers of diagnoses made, the need to manage challenging findings such as variants of unknown significance (VUS) and incidental findings (IF) also increased. We have summarized the current guidelines and recommendations and we have shown current solutions used in our tertiary center in the Netherlands. We discuss four of the most common clinical situations: fetus with normal pES results, fetus with a pathogenic finding explaining the fetal phenotype, fetus with a variant of uncertain clinical significance fitting the phenotype and fetus with a variant leading to an incidental diagnosis. Additionally, we reflect on solutions in order to facilitate genetic counseling in an NGS-era.
| S-EPMC10198275 | biostudies-literature
Project description: Not available
| S-EPMC10702128 | biostudies-literature
Project description: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.
| S-EPMC10119849 | biostudies-literature
Project description:Background: Prenatal genetic counseling can be difficult, especially when it is related to fetuses with a rare thalassemia. An intronic variant located far from obvious regulatory sequences in the HBB gene could be very difficult to evaluate as it may affect the mRNA processing or cause β-thalassemia (β-thal). In the present study, a Chinese pregnant woman with HbJ-Bangkok and a very rare change in the second intron of the HBB gene [IVS-II-806(G>C), NM_000518.4, HBB: c.316-45G>C] in combination with α+-thalassemia was reported, which can assist in prenatal genetic counseling. Case Report: A 26-year-old pregnant woman presented at the obstetric clinic for a routine pregnancy check at 12 weeks of gestation. Red blood counts and high-performance liquid chromatography (HPLC) were consistent with clinical manifestations of anemia. Multiplex gap-polymerase chain (gap-PCR) displayed rightward deletion (-α3.7/αα). Direct DNA sequencing of the δ-globin gene showed no mutation. Sanger sequencing of the β-globin gene showed a previously undescribed condition of double heterozygosity for HbJ-Bangkok and a very rare change in the second intron of the HBB gene [IVS-II-806(G>C), NM_000518.4, HBB: c.316-45G>C] that has not been previously reported in the HbVar database. Thus, a rare combination of α+-thal and a compound heterozygosity of HbJ-Bangkok and [IVS-II-806(G>C)] with α+-thal (-α3.7/αα) was finally diagnosed. Prenatal genetic counseling was made based on the genotype and phenotype analyses. Conclusion: This study enlarges the mutation spectrum of β-globin gene and emphasizes DNA analysis in resolving unusual patterns in Hb analysis and the importance of sharing the observed rare undefined mutations and the possible interactions with known molecular defects, which can assist in prenatal genetic counseling.
| S-EPMC8194298 | biostudies-literature
Project description:Primary cardiac angiosarcomas are rare, but they are the most aggressive type of primary cardiac neoplasms. When patients do present, it is with advanced pulmonary and/or cardiac symptoms. Therefore, many times the correct diagnosis is not made at the time of initial presentation. These patients have metastatic disease and the vast majority of these patients die within a few months after diagnosis. Currently the treatment choices are limited and there are no targeted therapies available.A 56-year-old male presented with shortness of breath, night sweats, and productive cough for a month. Workup revealed pericardial effusion and multiple bilateral pulmonary nodules suspicious for metastatic disease. Transthoracic echocardiogram showed a large pericardial effusion and a large mass in the base of the right atrium. Results of biopsy of bilateral lung nodules established a diagnosis of primary cardiac angiosarcoma. Aggressive pulmonary disease caused rapid deterioration; the patient went on hospice and subsequently died. Whole exome sequencing of the patient's postmortem tumor revealed a novel KDR (G681R) mutation, and focal high-level amplification at chromosome 1q encompassing MDM4, a negative regulator of TP53.Mutations in KDR have been reported previously in angiosarcomas. Previous studies also demonstrated that KDR mutants with constitutive KDR activation could be inhibited with specific KDR inhibitors in vitro. Thus, patients harboring activating KDR mutations could be candidates for treatment with KDR-specific inhibitors.
| S-EPMC5217318 | biostudies-literature
Project description:BackgroundPrimary pulmonary lymphoepithelioma-like carcinoma (LELC) is a rare tumor subtype accounting for around 0.9% of lung cancers. At present, research on LELC mainly focuses on pathological diagnosis, while the molecular mutation landscape is still unclear.Case presentationA 72-year-old female presented a productive cough for three weeks followed by severe symptoms for another week. Respiratory sounds were weak and coarser in the right lung field. F-FDG PET-CTA showed a hypermetabolic mass in the upper lobe of the right lung as well as the enlargement of right hilar and subcarinal lymph nodes. Hematoxylin-eosin staining and immunohistochemistry staining of the biopsy established the diagnosis of primary pulmonary LELC. After thoracoscopic-assisted radical resection of right lung cancer and middle lobe of right lung, the patient's vital signs were stable without apparent productive cough, chest pain, chest tightness and other subjective discomforts. Furtherwhole exome sequencing of the patient's tumor tissue and leukocytes (served as a germline mutation control) revealed 613 somatic gene mutations, and of which mutations in PRIM2, KCNB1, CDH1, and ATRX were most likely related to the LELC pathogenesis. The recurrence of gene mutations from various cancers database and a tumor mutation burden (TMB) of 18.7 mutations/mb were revealed as well.ConclusionOur findings have illustrated the genomic profile of a primary pulmonary LELC case and provided a positive biomarker that immune checkpoint blockade is potentially effective for this patient in further treatment.
| S-EPMC6598353 | biostudies-literature
Project description:Background and Objectives: The development and standardization of genome-wide technologies able to carry out high-resolution, genomic analyses in a cost- and time-affordable way is increasing our knowledge regarding the molecular bases of complex diseases like autism spectrum disorder (ASD). ASD is a group of heterogeneous diseases with multifactorial origins. Genetic factors seem to be involved, albeit they remain still largely unknown. Here, we report the case of a child with a clinical suspicion of ASD investigated by using such a genomic high-resolution approach. Materials and Methods: Both array comparative genomic hybridization (aCGH) and exome sequencing were carried out on the family trio. aCGH was performed using the 4 × 180 K SurePrint G3 Human CGH Microarray, while the Human All Exon V7 targeted SureSelect XT HS panel was used for exome sequencing. Results: aCGH identified a paternally inherited duplication of chromosome 7 involving the CNTNAP2 gene, while 5 potentially clinically-relevant variants were identified by exome sequencing. Conclusions: Within the identified genomic alterations, the CNTNAP2 gene duplication may be related to the patient's phenotype. Indeed, this gene has already been associated with brain development and cognitive functions, including language. The paternal origin of the alteration cannot exclude an incomplete penetrance. Moreover, other genomic factors may act as phenotype modifiers combined with CNTNAP2 gene duplication. Thus, the case reported herein strongly reinforces the need to use extensive genomic analyses to shed light on the bases of complex diseases.
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Project description:Arteriovenous malformations of the brain (bAVMs) are plexuses of pathological arteries and veins that lack a normal capillary system between them. Intracranial hemorrhage (hemorrhagic stroke) is the most frequent clinical manifestation of AVM, leading to lethal outcomes that are especially high among children and young people. Recently, high-throughput genome sequencing methods have made a notable contribution to the research progress in this subject. In particular, whole-exome sequencing (WES) methods allow the identification of novel mutations. However, the genetic mechanism causing AVM is still unclear. Therefore, the aim of this study was to investigate the potential genetic mechanism underlying AVM. We analyzed the WES data of blood and tissue samples of a 30-year-old Central Asian male diagnosed with AVM. We identified 54 polymorphisms in 43 genes. After in-silica overrepresentation enrichment analysis of the polymorphisms, the SIRT1 gene variant (g.67884831C>T) indicated a possible molecular mechanism of bAVM. Further studies are required to evaluate the functional impact of SIRT1 g.67884831C>T, which may warrant further replication and biological investigations related to sporadic bAVM.
| S-EPMC9601721 | biostudies-literature