Novel <i>NUS1</i> deletion and 20q13.33 duplication in a pediatric patient with neurodevelopmental disorder and ataxia: A case report

This report describes the case of a 9-year-old girl presenting with global developmental delay, intellectual disability, features of autism spectrum disorder, ataxia, and tremors.Comprehensive genetic analyses using both chromosomal microarray analysis and whole genome sequencing identified chromosomal and single-gene variations.Chromosomal microarray analysis revealed a 20q13.33duplication encompassing genes critical for neuronal function and development.Subsequent whole genome sequencing further identified a novel NUS1 mutation which was further identified in her mother, who exhibited milder neurological manifestations.The concurrent presence of both genetic alterations may explain the more severe phenotype observed in the proband compared to the mother.This report underscores the importance of integrated genetic testing, such as dual chromosomal microarray analysis and whole genome sequencing, in diagnosing complex pediatric neurodevelopmental disorders.