Hopping as an Indicator of Chemotoxicity: Gait Analysis in Patients With Leukemia and Lymphoma.

BACKGROUND: Survivors of acute lymphoblastic leukemia (ALL) can experience chemotherapy-related changes in neuromuscular function, which can persist and impact the quality of life. Clinically, neuromuscular changes are assessed by observing gait. The primary aims of this study were to compare observational gait/functional movement analysis to matched electronic gait analysis in children with ALL and lymphoblastic lymphoma at specific time points during and after treatment. PATIENTS AND METHODS: Participants 2 to 27 years old diagnosed with ALL/lymphoblastic lymphoma who were on or off therapy within 10 years were eligible. Participants underwent electronic gait assessment using GAITRite, observational gait, and functional movement analysis and completed quality of life questionnaires. Parents also completed quality-of-life assessments. RESULTS: Electronic gait parameters were not different in this cohort compared with controls. Mean overall scores on observational gait and functional movement analysis improved over time. Hopping was the most frequent and walking was the least frequent noted deficit. Participants had a lower patient and parent-reported QoL scores compared with the general population. CONCLUSION: Observational gait and functional movement analysis identified more deficits than the electronic gait assessment. Future studies are warranted to determine whether hopping deficits are an early clinical indicator of toxicity and signal for intervention.

Pathogenic variants in USP7 cause a neurodevelopmental disorder with speech delays, altered behavior, and neurologic anomalies.

PURPOSE: Haploinsufficiency of USP7, located at chromosome 16p13.2, has recently been reported in seven individuals with neurodevelopmental phenotypes, including developmental delay/intellectual disability (DD/ID), autism spectrum disorder (ASD), seizures, and hypogonadism. Further, USP7 was identified to critically incorporate into the MAGEL2-USP7-TRIM27 (MUST), such that pathogenic variants in USP7 lead to altered endosomal F-actin polymerization and dysregulated protein recycling. METHODS: We report 16 newly identified individuals with heterozygous USP7 variants, identified by genome or exome sequencing or by chromosome microarray analysis. Clinical features were evaluated by review of medical records. Additional clinical information was obtained on the seven previously reported individuals to fully elucidate the phenotypic expression associated with USP7 haploinsufficiency. RESULTS: The clinical manifestations of these 23 individuals suggest a syndrome characterized by DD/ID, hypotonia, eye anomalies,feeding difficulties, GERD, behavioral anomalies, and ASD, and more specific phenotypes of speech delays including a nonverbal phenotype and abnormal brain magnetic resonance image findings including white matter changes based on neuroradiologic examination. CONCLUSION: The consistency of clinical features among all individuals presented regardless of de novo USP7 variant type supports haploinsufficiency as a mechanism for pathogenesis and refines the clinical impact faced by affected individuals and caregivers.