Biallelic variants in GTPBP3: New patients, phenotypic spectrum, and outcome

INTRODUCTION

COXPD23 is a rare mitochondrial disease caused by biallelic pathogenic variants in GTPBP3. We report on two siblings with a mild phenotype.

CASE REPORTS

The young boy presented with global developmental delay, ataxic gait and upper limbs tremor, and the older sister with absence seizures and hypertrophic cardiomyopathy. Respiratory chain impairment was confirmed in muscle.

DISCUSSION

Reviewed cases point toward clustering around two prevalent phenotypes: an early-onset presentation with severe fatal encephalopathy and a late milder presentation with global developmental delay/ID and cardiopathy, with the latter as, is the main feature. Our patients showed an intermediate phenotype with intrafamilial variability.

Molecularly Targeted Lanthanide Nanoparticles for Cancer Theranostic Applications

Injectable colloidal solutions of lanthanide oxides (nanoparticles between 10 and 100 nm in size) have demonstrated high biocompatibility and no toxicity when the nanoparticulate units are functionalized with specific biomolecules that molecularly target various proteins in the tumor microenvironment. Among the proteins successfully targeted by functionalized lanthanide nanoparticles are folic receptors, fibroblast activation protein (FAP), gastrin-releasing peptide receptor (GRP-R), prostate-specific membrane antigen (PSMA), and integrins associated with tumor neovasculature. Lutetium, samarium, europium, holmium, and terbium, either as lanthanide oxide nanoparticles or as nanoparticles doped with lanthanide ions, have demonstrated their theranostic potential through their ability to generate molecular images by magnetic resonance, nuclear, optical, or computed tomography imaging. Likewise, photodynamic therapy, targeted radiotherapy (neutron-activated nanoparticles), drug delivery guidance, and image-guided tumor therapy are some examples of their potential therapeutic applications. This review provides an overview of cancer theranostics based on lanthanide nanoparticles coated with specific peptides, ligands, and proteins targeting the tumor microenvironment.

The Impact of COVID-19 on Treatment Practices for Patients With Early Breast Cancer: A Cross-Sectional Study From a Large Cancer Center in Italy

INTRODUCTION

The Coronavirus Disease 2019 (COVID-19) has disrupted health services worldwide. The evidence on the impact of the pandemic on cancer care provision, however, is conflicting. We aimed to audit the management of patients diagnosed with early breast cancer (EBC) during the pandemic in a large, tertiary-level cancer center in Italy.

METHODS

We conducted a cross-sectional study to track the route to first treatment for patients diagnosed with EBC during 2019, 2020, and 2021. We abstracted data for all consecutive patients referred to the Veneto Institute of Oncology (Padua, Italy). We defined as point of contact (POC) the date of the first consultation with a breast cancer specialist of the breast unit. First treatment was defined as either upfront surgery or neoadjuvant chemotherapy (NACT).

RESULTS

We reviewed medical records for 878 patients for whom an MDT report during 2019-2021 (April through June) was available. Of these, 431 (49%) were eligible. The proportion of screen-detected tumors was larger in 2019 and 2021 than in 2020 (59%). Conversely, the proportion of screen-detected tumors was offset by the proportion of palpable tumors in 2020 (P = .004). Distribution of tumor and nodal stage was unchanged over time, but in situ tumors were slightly fewer in 2020 than in 2019 or 2021. The adjusted odds ratio for treatment delay (45 days or more) was 0.87 for 2020 versus 2019 (95% CI, 0.5-1.53) and 0.9 for 2021 versus 2019 (95% CI, 0.52-1.55).

CONCLUSIONS

There was no evidence for major changes in the management of patients with EBC during 2019-2021 and no treatment delays were observed. Our findings suggest that more women presented with palpable nodules at diagnosis, but the stage distribution did not change over time. Validation on a larger cohort of patients is warranted to robustly assess the impact of the COVID-19 pandemic on treatment practices for patients with EBC.

Effects of cohort, genotype, variant, and maternal β-blocker treatment on foetal heart rate predictors of inherited long QT syndrome

AIMS

In long QT syndrome (LQTS), primary prevention improves outcome; thus, early identification is key. The most common LQTS phenotype is a foetal heart rate (FHR) < 3rd percentile for gestational age (GA) but the effects of cohort, genotype, variant, and maternal β-blocker therapy on FHR are unknown. We assessed the influence of these factors on FHR in pregnancies with familial LQTS and developed a FHR/GA threshold for LQTS.

METHODS AND RESULTS

In an international cohort of pregnancies in which one parent had LQTS, LQTS genotype, familial variant, and maternal β-blocker effects on FHR were assessed. We developed a testing algorithm for LQTS using FHR and GA as continuous predictors. Data included 1966 FHRs at 7-42 weeks' GA from 267 pregnancies/164 LQTS families [220 LQTS type 1 (LQT1), 35 LQTS type 2 (LQT2), and 12 LQTS type 3 (LQT3)]. The FHRs were significantly lower in LQT1 and LQT2 but not LQT3 or LQTS negative. The LQT1 variants with non-nonsense and severe function loss (current density or β-adrenergic response) had lower FHR. Maternal β-blockers potentiated bradycardia in LQT1 and LQT2 but did not affect FHR in LQTS negative. A FHR/GA threshold predicted LQT1 and LQT2 with 74.9% accuracy, 71% sensitivity, and 81% specificity.

CONCLUSION

Genotype, LQT1 variant, and maternal β-blocker therapy affect FHR. A predictive threshold of FHR/GA significantly improves the accuracy, sensitivity, and specificity for LQT1 and LQT2, above the infant's a priori 50% probability. We speculate this model may be useful in screening for LQTS in perinatal subjects without a known LQTS family history.

Clinical presentation of calmodulin mutations: the International Calmodulinopathy Registry

AIMS

Calmodulinopathy due to mutations in any of the three CALM genes (CALM1-3) causes life-threatening arrhythmia syndromes, especially in young individuals. The International Calmodulinopathy Registry (ICalmR) aims to define and link the increasing complexity of the clinical presentation to the underlying molecular mechanisms.

METHODS AND RESULTS

The ICalmR is an international, collaborative, observational study, assembling and analysing clinical and genetic data on CALM-positive patients. The ICalmR has enrolled 140 subjects (median age 10.8 years [interquartile range 5-19]), 97 index cases and 43 family members. CALM-LQTS and CALM-CPVT are the prevalent phenotypes. Primary neurological manifestations, unrelated to post-anoxic sequelae, manifested in 20 patients. Calmodulinopathy remains associated with a high arrhythmic event rate (symptomatic patients, n = 103, 74%). However, compared with the original 2019 cohort, there was a reduced frequency and severity of all cardiac events (61% vs. 85%; P = .001) and sudden death (9% vs. 27%; P = .008). Data on therapy do not allow definitive recommendations. Cardiac structural abnormalities, either cardiomyopathy or congenital heart defects, are present in 30% of patients, mainly CALM-LQTS, and lethal cases of heart failure have occurred. The number of familial cases and of families with strikingly different phenotypes is increasing.

CONCLUSION

Calmodulinopathy has pleiotropic presentations, from channelopathy to syndromic forms. Clinical severity ranges from the early onset of life-threatening arrhythmias to the absence of symptoms, and the percentage of milder and familial forms is increasing. There are no hard data to guide therapy, and current management includes pharmacological and surgical antiadrenergic interventions with sodium channel blockers often accompanied by an implantable cardioverter-defibrillator.

Is the equimolar mixture of oxygen and nitrous oxide (EMONO) associated with audiovisuals effective in reducing pain and side effects during peripheral venous access placement in children? Protocol for a single-centre randomised controlled trial from Italy

INTRODUCTION

Nurses frequently place a peripheral venous catheter during children's hospitalisation. Many studies suggest treatment of venipuncture-related pain. The administration of an equimolar mixture of oxygen and nitrous oxide (EMONO) is employed for pain control; however, no studies have analysed the association between EMONO and audiovisuals.The purpose of the study is to evaluate the effect of EMONO administration when combined with audiovisuals (EMONO+Audiovisual) versus EMONO alone on perceived pain, side effects and level of cooperation during peripheral venous access placement in children aged 2-5 years.

METHODS AND ANALYSIS

The first 120 eligible children admitted to the paediatric ward of the Lodi Hospital and presenting the indication for peripheral venous access will be enrolled. Sixty children will be randomly assigned to the experimental group (EMONO+Audiovisual) and 60 to the control group (EMONO alone).The Face, Legs, Activity, Cry, Consolability scale will be used to assess pain in the children aged 2-years old; pain in the children aged 3-5 years will be assessed using the Wong-Baker scale. The cooperation throughout the procedure will be measured using the Groningen Distress Rating Scale.

ETHICS AND DISSEMINATION

The Milan Area 1 Ethics Committee approved the study protocol (Experiment Registry No. 2020/ST/295). The trial results will be presented at conferences and published in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT05435118.

mGlu3 Metabotropic Glutamate Receptors as a Target for the Treatment of Absence Epilepsy: Preclinical and Human Genetics Data

BACKGROUND

Previous studies suggest that different metabotropic glutamate (mGlu) receptor subtypes are potential drug targets for treating absence epilepsy. However, no information is available on mGlu3 receptors.

OBJECTIVE

To examine whether (i) changes of mGlu3 receptor expression/signaling are found in the somatosensory cortex and thalamus of WAG/Rij rats developing spontaneous absence seizures; (ii) selective activation of mGlu3 receptors with LY2794193 affects the number and duration of spikewave discharges (SWDs) in WAG/Rij rats; and (iii) a genetic variant of GRM3 (encoding the mGlu3 receptor) is associated with absence epilepsy.

METHODS

Animals: immunoblot analysis of mGlu3 receptors, GAT-1, GLAST, and GLT-1; realtime PCR analysis of mGlu3 mRNA levels; assessment of mGlu3 receptor signaling; EEG analysis of SWDs; assessment of depressive-like behavior. Humans: search for GRM3 and GRM5 missense variants in 196 patients with absence epilepsy or other Idiopathic Generalized Epilepsy (IGE)/ Genetic Generalized Epilepsy (GGE) and 125,748 controls.

RESULTS

mGlu3 protein levels and mGlu3-mediated inhibition of cAMP formation were reduced in the thalamus and somatosensory cortex of pre-symptomatic (25-27 days old) and symptomatic (6-7 months old) WAG/Rij rats compared to age-matched controls. Treatment with LY2794193 (1 or 10 mg/kg, i.p.) reduced absence seizures and depressive-like behavior in WAG/Rij rats. LY2794193 also enhanced GAT1, GLAST, and GLT-1 protein levels in the thalamus and somatosensory cortex. GRM3 and GRM5 gene variants did not differ between epileptic patients and controls.

CONCLUSION

We suggest that mGlu3 receptors modulate the activity of the cortico-thalamo-cortical circuit underlying SWDs and that selective mGlu3 receptor agonists are promising candidate drugs for absence epilepsy treatment.