Which is identified as the leading known cause of mental retardation in the nation's children?

Which is identified as the leading known cause of mental retardation in the nation's children?

• A. fetal alcohol syndrome (FAS)
• B. Down syndrome
• C. autism
• D. lead poisoning

Answer: (C)

Understanding causes of intellectual disability in children often centers on conditions that reliably impact cognitive development. Autism is a neurodevelopmental disorder; while some individuals with autism have intellectual disability, autism itself is not the leading cause of intellectual disability. Down syndrome, caused by an extra copy of chromosome 21, is the most common genetic cause of intellectual disability and is widely recognized as a leading contributor to cognitive impairment in children. Fetal alcohol syndrome is a known preventable cause, but it is less prevalent. Lead poisoning can cause cognitive problems as well, but widespread prevention has reduced its prominence as a leading cause. So, Down syndrome best fits as the leading known cause among these options.

Understanding causes of intellectual disability in children often centers on conditions that reliably impact cognitive development. Autism is a neurodevelopmental disorder; while some individuals with autism have intellectual disability, autism itself is not the leading cause of intellectual disability. Down syndrome, caused by an extra copy of chromosome 21, is the most common genetic cause of intellectual disability and is widely recognized as a leading contributor to cognitive impairment in children. Fetal alcohol syndrome is a known preventable cause, but it is less prevalent. Lead poisoning can cause cognitive problems as well, but widespread prevention has reduced its prominence as a leading cause. So, Down syndrome best fits as the leading known cause among these options.