患儿男,8岁,系第4胎,足月顺产,无窒息,出生时体重3.5kg,母乳喂养。2岁左右开始行走,但步态不稳,易跌倒,智力低下,1岁半时始会发“爸、妈”单音外,至今仍无语言能力,生活也完全不能自理,多动,不能控制自己的行为。无传染病史。父母非近亲婚配。出生时父亲36岁,母龄32岁,否认妊娠期服药及毒物接触史。双亲的表型正常。患儿同胞的表型及智力均正常。否认有家族遗传病史。体检:身高133cm,体重24kg,面容呆板,耳廓稍低,口常张开,走路缓慢、欠稳、轻度跛行,易跌到。心肺未见异常,外生殖器比同龄儿小,双侧睾丸未下降。头部CT扫描诊断为脑发育不全。 Pediatric male, 8 years old, is the 4th child, with full term ascites, asphyxiation, 3.5kg at birth, and breastfed. 2-year-old began to walk, but the unsteady gait, easy to fall, mental retardation, 1 year and a half will be made before the “Dad, Mom” ​​tone, there is still no language skills, life is completely unable to take care of themselves, , Can not control their own behavior. No history of infectious disease. Parents non-relatives marriage. 36-year-old father, mother of 32 years old, denied pregnancy medication and poison exposure history. Parents of the normal phenotype. Children with siblings phenotype and intelligence are normal. Denied having a family history of genetic disease. Physical examination: height 133cm, weight 24kg, face dull, slightly lower auricle, open mouth, walking slowly, unstable, mild limp, easy to fall. Cardiopulmonary no abnormalities, external genitalia than their children, bilateral testis did not decline. Head CT scan diagnosis of hypoplasia.