The GTPBP2 gene encodes a guanosine triphosphate (GTP)‐binding protein of unknown function. Biallelic loss‐of‐function variants in the GTPBP2 gene have been previously reported in association with a neuro‐ectodermal clinical presentation in six individuals from four unrelated families. Here, we provide detailed descriptions of three additional individuals from two unrelated families in the context of the previous literature. Both families carry nonsense variants in GTPBP2: homozygous p.(Arg470*) and compound heterozygous p.(Arg432*)/p.(Arg131*). Key features of this clinically recognizable condition include prenatal onset microcephaly, tone abnormalities, and movement disorders, epilepsy, dysmorphic features, retinal dysfunction, ectodermal dysplasia, and brain iron accumulation. Our findings suggest that some aspects of the clinical presentation appear to be age‐related; brain iron accumulation may appear only after childhood, and the ectodermal findings and peripheral neuropathy are most prominent in older individuals. In addition, we present prenatal and neonatal findings as well as the first Caucasian and black African families with GTPBP2 biallelic variants. The individuals described herein provide valuable additional phenotypic information about this rare, novel, and progressive neuroectodermal condition.

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Purpose: The aim of our study was to compare whole-body diffusion-weighted MRI (WB-DWI-MRI) to fluoro-2-deoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) in the assessment of initial staging and treatment response in pediatric patients with Hodgkin lymphoma. Materials and Methods: This prospective study comprised 11 children with Hodgkin lymphoma. Whole-body DWI-MRI and FDG-PET/CT were obtained at baseline and after 2 cycles of chemotherapy. Two radiologists measured the apparent diffusion coefficient (ADC) values of the sites of involvement agreed upon in consensus and 1 nuclear medicine physician assessed the PET/CT. Reliability of radiologists’ ratings was assessed by intraclass correlation coefficients (ICC2,1). The sensitivity and positive predictive value (PPV) of DW-MRI relative to PET/CT were calculated for nodal and extranodal sites. The patients were staged according to both modalities. Association of treatment responses was assessed through the Pearson correlation between the ADC ratios and the change standardized uptake value (SUV) between baseline and follow-up. Results: There was good agreement between the raters for nodal and extranodal ADC measurements. The sensitivity and PPV of DW-MRI relative to PET/CT of nodal disease was 0.651 and 1.0, respectively, at baseline, and 0.697 and 0.885 at follow-up. The sensitivity and PPV of extranodal disease were 0.545 and 0.6 at baseline, and 0.167 and 0.333 at follow-up. Diffusion-weighted MRI determined correct tumor stage in 8 of 11 examinations. There was poor correlation between the ADC ratios and the absolute change in SUV between baseline and follow-up (0.348). Conclusion: Our experience showed that WB-DWI-MRI is inferior to PET/CT for initial staging and assessment of treatment response of Hodgkin lymphoma in pediatric patients.

Objective: To retrospectively correlate imaging findings post-sclerotherapy of low-flow vascular malformations with clinical outcome. Materials and Methods: We retrospectively evaluated 81 pediatric patients who had sclerotherapy in our department over a 14-year period. Patients with a diagnosis of low-flow vascular malformation, pre and post-treatment ultrasound (US) and clinical follow-up evaluation were included in the study. Exclusion criteria were coexisting high-flow vascular malformations, history of additional surgical or medical treatment to their malformation and large infiltrative lesions difficult to measure on US. Pre and post-treatment sonographic volumes of the malformation were assessed. Changes in volume were categorized into 6- increased volume, stable and volume decrease of 1-25%/26-50%/51-75%/75-100%. Clinical outcomes were categorized into 4 – worse, no change, improved and symptom free. In cases where pre-treatment MRI was available, the estimated malformation volumes in both modalities were correlated using Spearman’s rank correlation. The change in sonographic volume was correlated with clinical outcome using Spearman’s rank correlation. P-values < .05 were considered significant. Results: Twenty-nine patients were included in the study; 13 with venous malformation (VM), and 16 with lymphatic malformation (LM). Nineteen patients had both pre-treatment US and MRI, showing correlation in volume between the 2 modalities ( P < .001). Post-treatment change in volume correlated with clinical outcome for combined venous and LMs (rho = .44, P = .02). No correlation was found when venous (rho = .48, P = .09) and lymphatic (rho = .33, P = .21) malformations were considered separately. Conclusion: Ultrasound can potentially be used as an objective tool in evaluating sclerotherapy treatment response of low-flow vascular malformations in the pediatric population.