Studies show that iodine deficiency is the leading preventable cause of mental retardation .
研究显示，缺碘是智力发育迟缓的一个主要但可预防的因素。
Unlike people with classic autism , which is often accompanied by mental retardation , those with asperger 's have normal language development and intelligence .
与通常伴随精神发育迟缓的典型自闭症患者不同，阿斯伯格综合症患者具有正常的语言能力和智力。
Autism encompasses a wide spectrum of disorders , ranging from profound inability to communicate and mental retardation to relatively mild symptoms , as in asperger 's syndrome .
