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Disruptive Behavior, Global Developmental Delay, and Obesity in a 5-Year-Old Boy with a Chromosome Microduplication
Adam Braddock1, Miguel Del Campo2, Michael I Reiff3
1Developmental Behavioral Pediatrics, Department of Pediatrics, University of California San Diego, Rady Children's Hospital, San Diego, CA.
Insights
A 5-year-old boy with developmental delay showed autism symptoms later in childhood. Genetic testing revealed a 2p25.3 microduplication, suggesting a potential cause for his autism diagnosis.
Area of Science:
- Developmental Behavioral Pediatrics
- Neurogenetics
- Autism Spectrum Disorder Research
Background:
- A 5-year-old boy presented with global developmental delay and disruptive behaviors.
- Medical history included tethered spinal cord repair, exotropia, and severe obesity.
- Initial assessments at 19 months showed no significant concerns for autism spectrum disorder.
Observation:
- The child exhibited significant behavioral challenges: hyperactivity, aggression, tantrums, short attention span, and sleep difficulties.
- Repetitive behaviors such as head rocking, stereotyped movements, and perseverative speech were noted.
- Expressive language was severely limited, with only one-word utterances at age 5.
Findings:
- Repeat psychological testing at age 5, including the Autism Diagnostic Observation Schedule-2 (ADOS-2), indicated autism with a high symptom severity.
- Genetic analysis revealed a microduplication on chromosome 2p25.3, encompassing the myelin transcription factor 1-like (MYT1L) gene.
- Fragile X testing was negative.
Implications:
- This case highlights the potential for later-onset autism spectrum disorder diagnosis in children with developmental delays.
- The identified 2p25.3 microduplication involving MYT1L may be a contributing genetic factor to the observed neurodevelopmental phenotype.
- Further research into the role of MYT1L in neurodevelopment and autism is warranted.
Case:
Ryan is a 5-year-old boy who was seen in a Developmental Behavioral Pediatrics clinic for disruptive behavior and developmental delay. His medical history was notable for a tethered spinal cord repaired at age 4 months, alternating exotropia with multiple surgeries, and obesity (body mass index at 99%). Ryan's development was globally delayed. He sat at age 10 months and walked at 24 months. An Autism Diagnostic Observation Schedule-Toddler module (ADOS-T) was completed at age 19 months and demonstrated little-to-no concern for autism spectrum disorder.Ryan's parents described behavioral challenges including hyperactivity, impulsivity, aggression toward him self and others, severe tantrums, a short attention span, and difficulty sleeping. They also endorsed repetitive behaviors including head rocking, walking in circles, and perseverative speech. Expressive language was significantly limited. There was no family history of autism or intellectual disability.Ryan's physical examination was notable for alternating exotropia, hypertelorism, upslanting palpebral fissures, and obesity. His speech was limited to 1-word utterances. Neurological and general examinations were normal.He was referred for repeat psychological testing at age 5 years. The ADOS-2 (Module 2) was consistent with a classification of autism with a high level of autism-related symptoms. A fragile X test was negative, and microarray demonstrated a microduplication in the region of 2p25.3 including the myelin transcription factor 1-like gene.
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