本文介绍了精神迟滞的病因及其影响发病率和患病率的因素,精神迟滞的发病率较高,原因是多方面的,其中大多是在出生前或乳儿早期,遗传因素是主要的。导致精神迟滞的主要疾病及发病率如下(每10万人口中):染色体异常:Down综合征100,18三体征20,XXX100,XXY150。中枢神经畸形:无脑症60,脊椎裂3,脑积水15～40。遗传性疾病:结节性硬化症5,雷克林病20～30,苯丙酮尿症1.5。其它:克汀病15～20,Vk缺乏性颅内出血25,缺氧性脑瘫40～50,难治性癫痫80～150。随着医学的进步 This article describes the etiology of mental retardation and its impact on morbidity and prevalence. The incidence of mental retardation is high for a number of reasons, most of which are predisposed to prenatal or early infancy. The main diseases and morbidity resulting in mental retardation are as follows (per 100,000 population): Chromosomal abnormalities: Down Syndrome 100,18 Trisomy 20, XXX100, XXY150. Central Nervous Deformity: no brain disease 60, 3 vertebrae, hydrocephalus 15 ~ 40. Hereditary diseases: tuberous sclerosis 5, 20 ~ 30, Parkinson’s disease, phenylketonuria 1.5. Others: Cretinism 15 ~ 20, Vk deficiency intracranial hemorrhage 25, hypoxic cerebral palsy 40 ~ 50, refractory epilepsy 80 ~ 150. With the progress of medicine