Sensory and verbal characteristics of a case of 9q21.13 microdeletion syndrome: a case report

The 9q21.13 microdeletion syndrome is an ultra-rare condition involving intellectual disability, language delay, and autistic features. Its low prevalence complicates early diagnosis. This report provides novel evidence on the neuropsychological profile, highlighting under-described sensory and verbal characteristics. A 9-year-old Colombian male child, of Native and European mixed ethnicity. He has a confirmed diagnosis of 9q21.13 microdeletion syndrome and autism spectrum disorder level 1, through a Hibridación Genómica Comparativa mediante Microarrays (Array CGH) exam and neuropsychological assessment. A comprehensive neuropsychological evaluation was conducted, including the Sensory Profile 2 and the Test for Auditory Comprehension of Language. The patient showed a percentile rank of 95 in sensory seeking, ≤ 85 in sensory avoidance, and >96 in sensory sensitivity, suggesting significant hyperreactivity to sensory stimuli. In auditory language comprehension, he obtained a total score of 47, with marked impairments in vocabulary (13), morphology (28), and syntax (6). Cognitive assessment revealed difficulties in sustained attention, planning, cognitive flexibility, and verbal reasoning, along with motor coordination issues affecting posture and balance. The patient also displayed heightened behavioral reactivity and a strong preference for sensory-rich environments when compared to same-age peers. This case illustrates the relevance of detailed neuropsychological evaluation in rare genetic conditions. The findings contribute to a deeper understanding of the sensory and linguistic manifestations of 9q21.13 microdeletion syndrome and support the need for individualized intervention plans. These should focus on enhancing language development, promoting sensory integration, and improving behavioral self-regulation. This report expands the clinical knowledge of rare neurodevelopmental syndromes and reinforces the importance of early, multidisciplinary assessments for guiding effective therapeutic and educational support.