scholarly journals Biallelic Pathogenic Variants in TNNT3 Associated With Congenital Myopathy

2021 ◽  
Vol 7 (3) ◽  
pp. e589
Author(s):  
Daniel G. Calame ◽  
Jawid Fatih ◽  
Isabella Herman ◽  
Zeynep Coban Akdemir ◽  
Haowei Du ◽  
...  

ObjectivePathogenic variants in TNNT3, the gene encoding fast skeletal muscle troponin T, were first described in autosomal dominant distal arthrogryposis type 2B2. Recently, a homozygous splice site variant, c.681+1G>A, was identified in a patient with nemaline myopathy and distal arthrogryposis. Here, we describe the second individual with congenital myopathy associated with biallelic TNNT3 variants.MethodsClinical exome sequencing data from a patient with molecularly undiagnosed congenital myopathy underwent research reanalysis. Clinical and histopathologic data were collected and compared with the single reported patient with TNNT3-related congenital myopathy.ResultsA homozygous TNNT3 variant, c.481-1G>A, was identified. This variant alters a consensus splice acceptor and is predicted to affect splicing by multiple in silico prediction tools. Both the patient reported here and the previously published patient exhibited limb, bulbar, and respiratory muscle weakness from birth, which improved over time. Other shared features include history of polyhydramnios, hypotonia, scoliosis, and high-arched palate. Distal arthrogryposis and nemaline rods, findings reported in the first patient with TNNT3-related congenital myopathy, were not observed in the patient reported here.ConclusionsThis report provides further evidence for the association of biallelic TNNT3 variants with severe recessive congenital myopathy with or without nemaline rods and distal arthrogryposis. TNNT3 sequencing and copy number analysis should be incorporated into the workup of congenital myopathies.

Author(s):  
Andreia Carvalho ◽  
Carmen Costa ◽  
Miguel Pinto ◽  
Ricardo Taipa ◽  
Ana Gonçalves ◽  
...  

AbstractX-linked myotubular myopathy (XLMTM), a centronuclear congenital myopathy secondary to pathogenic variants in the MTM1 gene encoding myotubularin, is typically recognized for its classic and severe phenotype which includes neonatal hypotonia, severe muscle weakness, long-term ventilator dependence, markedly delayed gross motor milestones with inability to independently ambulate, and a high neonatal and childhood mortality. However, milder congenital forms of the condition and other phenotypes are recognized. We describe a 6-year-old boy with a mild XLMTM phenotype with independent gait and no respiratory insufficiency even in the neonatal period. The child has a hemizygous novel splice site variant in the MTM1 gene (c.232–25A > T) whose pathogenicity was confirmed by cDNA studies (exon 5 skipping) and muscle biopsy findings. We also compared the phenotype of our patient with the few reported cases that presented a mild XLMTM phenotype and no respiratory distress at birth, and discussed the potential mechanisms underlying this phenotype such as the presence of residual expression of the normal myotubularin transcript.


2020 ◽  
pp. jmedgenet-2019-106714
Author(s):  
Justine Géraud ◽  
Klaus Dieterich ◽  
John Rendu ◽  
Emmanuelle Uro Coste ◽  
Murielle Dobrzynski ◽  
...  

BackgroundCongenital nemaline myopathies are rare pathologies characterised by muscle weakness and rod-shaped inclusions in the muscle fibres.MethodsUsing next-generation sequencing, we identified three patients with pathogenic variants in the Troponin T type 1 (TNNT1) gene, coding for the troponin T (TNT) skeletal muscle isoform.ResultsThe clinical phenotype was similar in all patients, associating hypotonia, orthopaedic deformities and progressive chronic respiratory failure, leading to early death. The anatomopathological phenotype was characterised by a disproportion in the muscle fibre size, endomysial fibrosis and nemaline rods. Molecular analyses of TNNT1 revealed a homozygous deletion of exons 8 and 9 in patient 1; a heterozygous nonsense mutation in exon 9 and retention of part of intron 4 in muscle transcripts in patient 2; and a homozygous, very early nonsense mutation in patient 3.Western blot analyses confirmed the absence of the TNT protein resulting from these mutations.DiscussionThe clinical and anatomopathological presentations of our patients reinforce the homogeneous character of the phenotype associated with recessive TNNT1 mutations. Previous studies revealed an impact of recessive variants on the tropomyosin-binding affinity of TNT. We report in our patients a complete loss of TNT protein due to open reading frame disruption or to post-translational degradation of TNT.


2017 ◽  
Vol 1 (3) ◽  
pp. 156-160
Author(s):  
Jacqueline Watchmaker ◽  
Sean Legler ◽  
Dianne De Leon ◽  
Vanessa Pascoe ◽  
Robert Stavert

Background: Although considered a tropical disease, strongyloidiasis may be encountered in non-endemic regions, primarily amongst immigrants and travelers from endemic areas.  Chronic strongyloides infection may be under-detected owing to its non-specific cutaneous presentation and the low sensitivity of commonly used screening tools. Methods: 18 consecutive patients with serologic evidence of strongyloides infestation who presented to a single urban, academic dermatology clinic between September 2013 and October 2016 were retrospectively included.  Patient age, sex, country of origin, strongyloides serology titer, absolute eosinophil count, presenting cutaneous manifestations, and patient reported subjective outcome of pruritus after treatment were obtained via chart review.  Results: Of the 18 patients, all had non-specific pruritic dermatoses, 36% had documented eosinophila and none were originally from the United States. A majority reported subjective improvement in their symptoms after treatment. Conclusion:  Strongyloides infection and serologic testing should be considered in patients living in non-endemic regions presenting with pruritic dermatoses and with a history of exposure to an endemic area.Key Points:Chronic strongyloidiasis can be encountered in non-endemic areas and clinical manifestations are variableEosinophilia was not a reliable indicator of chronic infection in this case series Dermatologists should consider serologic testing for strongyloidiasis in patients with a history of exposure and unexplained pruritus


BMJ ◽  
2021 ◽  
pp. n214
Author(s):  
Weedon MN ◽  
Jackson L ◽  
Harrison JW ◽  
Ruth KS ◽  
Tyrrell J ◽  
...  

Abstract Objective To determine whether the sensitivity and specificity of SNP chips are adequate for detecting rare pathogenic variants in a clinically unselected population. Design Retrospective, population based diagnostic evaluation. Participants 49 908 people recruited to the UK Biobank with SNP chip and next generation sequencing data, and an additional 21 people who purchased consumer genetic tests and shared their data online via the Personal Genome Project. Main outcome measures Genotyping (that is, identification of the correct DNA base at a specific genomic location) using SNP chips versus sequencing, with results split by frequency of that genotype in the population. Rare pathogenic variants in the BRCA1 and BRCA2 genes were selected as an exemplar for detailed analysis of clinically actionable variants in the UK Biobank, and BRCA related cancers (breast, ovarian, prostate, and pancreatic) were assessed in participants through use of cancer registry data. Results Overall, genotyping using SNP chips performed well compared with sequencing; sensitivity, specificity, positive predictive value, and negative predictive value were all above 99% for 108 574 common variants directly genotyped on the SNP chips and sequenced in the UK Biobank. However, the likelihood of a true positive result decreased dramatically with decreasing variant frequency; for variants that are very rare in the population, with a frequency below 0.001% in UK Biobank, the positive predictive value was very low and only 16% of 4757 heterozygous genotypes from the SNP chips were confirmed with sequencing data. Results were similar for SNP chip data from the Personal Genome Project, and 20/21 individuals analysed had at least one false positive rare pathogenic variant that had been incorrectly genotyped. For pathogenic variants in the BRCA1 and BRCA2 genes, which are individually very rare, the overall performance metrics for the SNP chips versus sequencing in the UK Biobank were: sensitivity 34.6%, specificity 98.3%, positive predictive value 4.2%, and negative predictive value 99.9%. Rates of BRCA related cancers in UK Biobank participants with a positive SNP chip result were similar to those for age matched controls (odds ratio 1.31, 95% confidence interval 0.99 to 1.71) because the vast majority of variants were false positives, whereas sequence positive participants had a significantly increased risk (odds ratio 4.05, 2.72 to 6.03). Conclusions SNP chips are extremely unreliable for genotyping very rare pathogenic variants and should not be used to guide health decisions without validation.


2020 ◽  
pp. 105566562098133
Author(s):  
Alyssa Fritz ◽  
Diana S. Jodeh ◽  
Fatima Qamar ◽  
James J. Cray ◽  
S. Alex Rottgers

Introduction: Oronasal fistulae following palatoplasty may affect patients’ quality of life by impacting their ability to eat, speak, and maintain oral hygiene. We aimed to quantify the impact of previous oronasal fistula repair on patients’ quality of life using patient-reported outcome psychometric tools. Methods: A cross-sectional study of 8- to 9-year-old patients with cleft palate and/or lip was completed. Patients who had a cleft team clinic between September 2018 and August 2019 were recruited. Participants were divided into 2 groups (no fistula, prior fistula repair). Differences in the individual CLEFT-Q and Child Oral Health Impact Profile-Short Form 19 (COHIP-SF 19) Oral Health scores between the 2 groups were evaluated using a multivariate analysis controlling for Veau classification and syndromic diagnosis. Results: Sixty patients with a history of cleft palate were included. Forty-two (70%) patients had an associated cleft lip. Thirty-two (53.3%) patients had no history of fistula and 28 (46.7%) patients had undergone a fistula repair. CLEFT-Q Dental, Jaw, and Speech Function were all higher in patients without a history of a fistula repair; however, none of these differences were statistically significant. The COHIP-SF 19 Oral Health score demonstrated a significantly lower score in the fistula group, indicating poorer oral health ( P = .05). Conclusions: One would expect that successful repair of a fistula would result in improved function and patient satisfaction, but the consistent trend toward lower CLEFT-Q scores and significantly increased COHIP-SF 19 Oral Health scores in our study group suggests that residual effects linger and that the morbidity of a fistula may not be completely treated with a secondary correction.


2021 ◽  
Author(s):  
Mauricio Mandel ◽  
Layton Lamsam ◽  
Pue Farooque ◽  
Dennis Spencer ◽  
Eyiyemisi Damisah

Abstract The insula is well established as an epileptogenic area.1 Insular epilepsy surgery demands precise anatomic knowledge2-4 and tailored removal of the epileptic zone with careful neuromonitoring.5 We present an operative video illustrating an intracranial electroencephalogram (EEG) depth electrode guided anterior insulectomy.  We report a 17-yr-old right-handed woman with a 4-yr history of medically refractory epilepsy. The patient reported daily nocturnal ictal vocalization preceded by an indescribable feeling. Preoperative evaluation was suggestive of a right frontal-temporal onset, but the noninvasive results were discordant. She underwent a combined intracranial EEG study with a frontal-parietal grid, with strips and depth electrodes covering the entire right hemisphere. Epileptiform activity was observed in contact 6 of the anterior insula electrode. The patient consented to the procedure and to the publication of her images.  A right anterior insulectomy was performed. First, a portion of the frontal operculum was resected and neuronavigation was used for the initial insula localization. However, due to unreliable neuronavigation (ie, brain shift), the medial and anterior borders of the insular resection were guided by the depth electrode reference. The patient was discharged 3 d after surgery with no neurological deficits and remains seizure free.  We demonstrate that depth electrode guided insular surgery is a safe and precise technique, leading to an optimal outcome.


2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Mandi L. Pratt-Chapman ◽  
Ash B. Alpert ◽  
Daniel A. Castillo

Abstract Purpose Cancer research on sexual and gender minority (SGM) populations is gaining momentum. The purpose of this systematic review was to examine what is currently known in the research literature regarding patient-reported health outcomes after cancer treatment among SGM populations. Methods In March 2021, a medical librarian conducted a systematic keyword search on PubMed, Embase, Scopus, Web of Science, PsycINFO, ClinicalTrials.gov, and the Cochrane Central Register of Controlled Trials. The primary inclusion criterion was assessment of at least one physical, psychosocial, emotional, or functional patient-reported health outcome related to the impacts of cancer diagnosis and/or treatment. Articles that met inclusion criteria were reviewed in their entirety, charted in a Word Table, and assessed for quality. Quality considerations included study design, sampling approach, diversity of sample, measures used, and analytic procedures. Studies were synthesized based on type of cancer study participants experienced. Results Sixty-four studies were included in the final analysis: most were quantitative, secondary analyses or cross-sectional studies with convenience samples, and focused on people with a history of breast or prostate cancer. Differences between sexual minority men and women in terms of coping and resilience were noted. Few studies reported on experiences of transgender persons and none reported on experiences of intersex persons. Conclusions A growing literature describes the patient-reported health outcomes of SGM people with a history of cancer. This study summarizes important between-group differences among SGM and heterosexual, cisgender counterparts that are critical for clinicians to consider when providing care. Implications for cancer survivors Sexual orientation and gender identity are relevant to cancer survivors’ health outcomes. Subgroups of SGM people have differential experiences and outcomes related to cancer and its impacts.


Author(s):  
M. Luu ◽  
P. Vabres ◽  
H. Devilliers ◽  
R. Loffroy ◽  
A. Phan ◽  
...  

ABSTRACT Purpose PIK3CA pathogenic variants in the PIK3CA-related overgrowth spectrum (PROS) activate phosphoinositide 3-kinase signaling, providing a rationale for targeted therapy, but no drug has proven efficacy and safety in this population. Our aim was to establish the six-month tolerability and efficacy of low-dose taselisib, a selective class I PI3K inhibitor, in PROS patients. Methods Patients over 16 years with PROS and PIK3CA pathogenic variants were included in a phase IB/IIA multicenter, open-label single-arm trial (six patients at 1 mg/day of taselisib, then 24 at 2 mg/day). The primary outcome was the occurrence of dose limiting toxicity (DLT). Efficacy outcomes were the relative changes after treatment of (1) tissue volume at affected and unaffected sites, both clinically and on imaging; (2) cutaneous vascular outcomes when relevant; (3) biologic parameters; (4) quality of life; and (5) patient-reported outcomes. Results Among 19 enrolled patients, 2 experienced a DLT (enteritis and pachymeningitis) leading to early trial termination (17 treated, 10 completed the study). No serious adverse reaction occurred in the 1 mg cohort (n = 6). No significant reduction in affected tissue volume was observed (mean −4.2%; p = 0.81; SD 14.01). Thirteen (76.4%) participants reported clinical improvement (pain reduction, chronic bleeding resolution, functional improvement). Conclusion Despite functional improvement, the safety profile of low-dose taselisib precludes its long-term use.


2021 ◽  
Author(s):  
Gema Ariceta ◽  
Fadi Fakhouri ◽  
Lisa Sartz ◽  
Benjamin Miller ◽  
Vasilis Nikolaou ◽  
...  

ABSTRACT Background Eculizumab modifies the course of disease in patients with atypical hemolytic uremic syndrome (aHUS), but data evaluating whether eculizumab discontinuation is safe are limited. Methods Patients enrolled in the Global aHUS Registry who received ≥1 month of eculizumab before discontinuing, demonstrated hematologic or renal response prior to discontinuation and had ≥6 months of follow-up were analyzed. The primary endpoint was the proportion of patients suffering thrombotic microangiopathy (TMA) recurrence after eculizumab discontinuation. Additional endpoints included: eGFR changes following eculizumab discontinuation to last available follow-up; number of TMA recurrences; time to TMA recurrence; proportion of patients restarting eculizumab; and changes in renal function. Results We analyzed 151 patients with clinically diagnosed aHUS who had evidence of hematologic or renal response to eculizumab, before discontinuing. Thirty-three (22%) experienced a TMA recurrence. Univariate analysis revealed that patients with an increased risk of TMA recurrence after discontinuing eculizumab were those with a history of extrarenal manifestations prior to initiating eculizumab, pathogenic variants, or a family history of aHUS. Multivariate analysis showed an increased risk of TMA recurrence in patients with pathogenic variants and a family history of aHUS. Twelve (8%) patients progressed to end-stage renal disease after eculizumab discontinuation; 7 (5%) patients eventually received a kidney transplant. Forty (27%) patients experienced an extrarenal manifestation of aHUS after eculizumab discontinuation. Conclusions Eculizumab discontinuation in patients with aHUS is not without risk, potentially leading to TMA recurrence and renal failure. A thorough assessment of risk factors prior to the decision to discontinue eculizumab is essential.


Genetics ◽  
2002 ◽  
Vol 161 (1) ◽  
pp. 259-267 ◽  
Author(s):  
Joachim Altschmied ◽  
Jacqueline Delfgaauw ◽  
Brigitta Wilde ◽  
Jutta Duschl ◽  
Laurence Bouneau ◽  
...  

Abstract The microphthalmia-associated transcription factor (MITF) exists in at least four isoforms. These are generated in higher vertebrates using alternative 5′ exons and promoters from a single gene. Two separate genes (mitf-m and mitf-b), however, are present in different teleost fish species including the poeciliid Xiphophorus, the pufferfishes Fugu rubripes and Tetraodon nigroviridis, and the zebrafish Danio rerio. Fish proteins MITF-m and MITF-b correspond at both the structural and the expression levels to one particular bird/mammalian MITF isoform. In the teleost lineage subfunctionalization of mitf genes after duplication at least 100 million years ago is associated with the degeneration of alternative exons and, probably, regulatory elements and promoters. For example, a remnant of the first exon specific for MITF-m is detected within the pufferfish gene encoding MITF-b. Retracing the evolutionary history of mitf genes in vertebrates uncovered the differential recruitment of new introns specific for either the teleost or the bird/mammalian lineage.


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