A medical student is on a developmental pediatrics rotation and is learning about the epidemiology of autism spectrum disorder (ASD) from recent U.S. CDC data. The student prepares a slide for a presentation summarizing the key demographic features of the condition. The student’s slide would be most accurate if it reported which of the following patterns?
A 16-year-old female with Down syndrome, who was previously social and functioning well at her baseline, presents with a several-month history of progressive social withdrawal, increased anxiety, and a notable decline in her adaptive skills, including self-care. Her parents also report periods of tearfulness for no apparent reason. In addition to a mood disorder like depression, which specific neurobehavioral condition must be considered in the differential diagnosis?
A 5-year-old boy with Fragile X syndrome and a co-occurring diagnosis of Autism Spectrum Disorder has significant expressive language delays and anxiety. A clinical trial of sertraline is initiated. What additional benefit might be observed in this child?
A 14-year-old boy is being evaluated for long-standing learning difficulties, significant anxiety, and behaviors consistent with attention-deficit/hyperactivity disorder. On physical examination, he has a long, narrow face, large, prominent ears, and hyperextensible finger joints. If genetic testing confirms Fragile X syndrome, which additional physical finding is most likely to be present?
A 4-year-old boy receives a new diagnosis of Autism Spectrum Disorder. His physical examination is notable for a head circumference that is 2.8 standard deviations above the mean, but is otherwise unremarkable. Initial genetic testing with a chromosomal microarray and Fragile X DNA analysis are negative. Given the significant macrocephaly, testing for pathogenic variants in which of the following genes should be specifically considered?
An adolescent with Attention-deficit/hyperactivity disorder (ADHD) and a history of stimulant medication use is suspected of substance abuse. Which statement best describes the relationship between ADHD treatment and substance use?
A child is undergoing formal psychological testing as part of an evaluation for developmental concerns. The psychologist explains to the parents that the standardized intelligence test they are using has a mean score of 100 and a standard deviation of 15. A significant impairment in general intellectual function, which is a core criterion for intellectual disability, is defined as a performance score approximately how many standard deviations below the mean?
A 7-year-old boy with a confirmed diagnosis of Fragile X syndrome is in his elementary school classroom. He is frequently overwhelmed during group activities, avoids eye contact, and can have emotional outbursts when the classroom is noisy. His teachers observe that he seems to want to interact with peers but quickly becomes agitated and withdraws. What is the most likely underlying driver of this social avoidance and challenging behavior?
A child with autism spectrum disorder is described as using scripted language and having difficulty with conversational turn-taking. Which aspect of language is MOST impaired in this case?
A 5-day-old infant with features of Down syndrome, including hypotonia and a flat facial profile, develops bilious emesis and progressive abdominal distension. An abdominal x-ray is obtained and reveals a “double bubble” sign. This classic radiographic finding is most characteristic of which congenital anomaly?
