gene panel sequencing
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Gene panel sequencing (NGS) offers the possibility to analyze rare forms of monogenic diabetes (MgD). To that end, 18 genes were analyzed in 1676 patients referred for MODY genetic testing. <p>Among the 307 patients with a molecular diagnosis of MgD, 55 (17.9%) were mutated in a gene associated with a genetic syndrome. Eight percent (n=25) of the patients with mutations carried the m.3243A>G variant associated with MIDD (Maternally inherited diabetes and deafness). At time of referral very little had reported hearing loss or any other element of the typical syndromic presentation. Six percent of the patients were mutated in <i>HNF1B</i> even though the typical extra-pancreatic features were not known at time of referral. Surprisingly the third most prominent etiology in these rare forms was the <i>WFS1</i> gene accounting for 2.9% of the patients with pathogenic mutations (n=9). None of them depicted a Wolfram syndrome presentation even though some features were reported in 6/9 patients. </p> <p>Restricting the analysis of certain genes to patients with the respective specific phenotypes would miss out those with partial presentations. These results therefore underlie the undisputable benefit of NGS strategies even though the situation implies cascade consequences both for the molecular biologist and the clinician.</p>

Gene panel sequencing (NGS) offers the possibility to analyze rare forms of monogenic diabetes (MgD). To that end, 18 genes were analyzed in 1676 patients referred for MODY genetic testing. <p>Among the 307 patients with a molecular diagnosis of MgD, 55 (17.9%) were mutated in a gene associated with a genetic syndrome. Eight percent (n=25) of the patients with mutations carried the m.3243A>G variant associated with MIDD (Maternally inherited diabetes and deafness). At time of referral very little had reported hearing loss or any other element of the typical syndromic presentation. Six percent of the patients were mutated in <i>HNF1B</i> even though the typical extra-pancreatic features were not known at time of referral. Surprisingly the third most prominent etiology in these rare forms was the <i>WFS1</i> gene accounting for 2.9% of the patients with pathogenic mutations (n=9). None of them depicted a Wolfram syndrome presentation even though some features were reported in 6/9 patients. </p> <p>Restricting the analysis of certain genes to patients with the respective specific phenotypes would miss out those with partial presentations. These results therefore underlie the undisputable benefit of NGS strategies even though the situation implies cascade consequences both for the molecular biologist and the clinician.</p>

Dengue fever and chikungunya are viral diseases that have spread rapidly throughout the world in recent decades. The occurrence of complications is well known, including prerenal acute kidney injury (AKI), which is usually thought to be caused by dehydration and fluid loss. Thrombotic microangiopathy (TMA) is an uncommon aggravation of dengue fever and chikungunya, with only a few cases described in the medical literature. The aim of this study is to present 3 cases of TMA associated with arboviral infection. Three patients with clinical history, laboratory test, and kidney biopsy results compatible with TMA were selected for the study, 2 of whom had a serological diagnosis of dengue fever and 1 of chikungunya. The 3 patients were followed up at the Federal University of Maranhão Hospital’s Nephrology Service in 2018. A targeted gene panel sequencing (TGPS) plus multiple to atypical hemolytic uremic syndrome (aHUS) multiplex ligation–dependent probe amplification (MLPA) was performed in 2 of the patients and revealed in the patient 1 a heterozygous pathogenic variant in the gene THBD, as well as heterozygous deletions in CFH, CFHR1, and CFHR3. In the patient 2, there were heterozygous pathogenic variant in the genes CFI and CFB, in addition to heterozygous deletions in the genes CFHR1 and CFHR3. Both received treatment with eculizumab and undergone recovery of renal function. The third patient had TMA not classified as either aHUS or thrombotic thrombocytopenic purpura (TTP); he abandoned the treatment and returned to the service after 2 years for a dialysis emergency. Patients with arboviral infectious disease and changes that suggest TMA should have appropriate support to establish early diagnosis and useful treatment.

Maturity-onset diabetes of the young (MODY) has about a dozen known causal genes to date, the most common ones being HNF1A, HNF4A, HNF1B and GCK. The phenotype of this clinically and genetically heterogeneous form of diabetes depends on the gene in which the patient has the mutation. We have tested 450 Hungarian index patients with suspected MODY diagnosis with Sanger sequencing and next-generation sequencing and found a roughly 30% positivity rate. More than 70% of disease-causing mutations were found in the GCK gene, about 20% in the HNF1A gene and less than 10% in other MODY-causing genes. We found 8 pathogenic and 9 likely pathogenic mutations in the HNF1A gene in a total of 48 patients and family members. In the case of HNF1A-MODY, the recommended first-line treatment is low dose sulfonylurea but according to our data, the majority of our patients had been on unnecessary insulin therapy at the time of requesting their genetic testing. Our data highlights the importance of genetic testing in the diagnosis of MODY and the establishment of the MODY subtype in order to choose the most appropriate treatment.

Background: BRAF, when mutated at V600E, is a potent oncogenic driver in melanoma, lung and colorectal cancer with well understood signaling mechanisms and established treatment guidelines. Non-V600E mutations are less common, more functionally diverse and do not yet have clear treatment guidelines. One class of non-V600E mutations are BRAF fusion genes which typically involve the C-terminal kinase domain of BRAF joined to one of a wide repertoire of potential N-terminal fusion partners. Here, we functionally characterized an MKRN1-BRAF fusion gene which we detected in multi-gene panel sequencing of a metastatic colorectal tumor. Methods: Levels of MEK/ERK pathway activity were evaluated by western blotting in HEK293 cells ectopically expressing MKRN1-BRAF or a series of other BRAF constructs. Dependence on dimerization was evaluated by introducing a dimerization deficiency mutation and drug sensitivity was evaluated by treatment with sorafenib, dabrafenib and trametinib. Results: MKRN1-BRAF potently activated MEK/ERK signaling and did not require dimerization for activity. Among the inhibitors evaluated, trametinib most effectively suppressed MKRN1-BRAF driven pathway activity. Conclusion: Our data demonstrate that the MKRN1-BRAF fusion gene encodes an oncoprotein that strongly activates MEK/ERK signaling in a trametinib-sensitive manner.

Gene panel sequencing of metastatic castrate-resistant prostate cancer (mCRPC) can assist in identifying appropriate targeted therapies. Although some studies have reported single DNA mutations, this is the first case of mCRPC with five different DNA mutations based on gene panel analysis. The patient, a 75-year-old man, initially presented with haematuria. Laboratory investigation revealed elevated prostate-specific antigen levels, and CT showed an enlarged prostate gland with metastatic lymph nodes. A 12-core biopsy revealed adenocarcinoma of the prostate. Gene panel sequencing demonstrated five different DNA mutations associated with sensitivities to olaparib and pembrolizumab. Treatment failure after hormonal therapy with leuprorelin and bicalutamide resulted in the initiation of chemotherapy with docetaxel. Over the past decade, development of genome sequencing analysis may guide us with more precise targeted therapy specific to mCRPC early on, especially with poly (ADP-ribose) polymerase inhibitors may show survival benefits.