患儿女,10个月,因“气喘10d,呼吸困难0.5d”于2015年4月5日入院。既往体质差,曾4次因“下呼吸道感染”住院。第2胎第2产,胎龄34周,出生体重1.98kg,无窒息抢救。生后混合喂养,8个月起添加米糊,进食无发绀,5个月抬头,8个月独坐,平素活动量正常,无多汗,无活动后气促、发绀表现。无毒物、放射性物质接触史。父母均体健,非近亲结婚,有一姐,体健,无家族遗传病史。入院查体:体 Children with children, 10 months, due to “asthma 10d, dyspnea 0.5d ” was admitted on April 5, 2015. Past physique is poor, had 4 times because of “lower respiratory tract infection” hospitalization. The second child of the second production, gestational age 34 weeks, birth weight 1.98kg, no asphyxia rescue. Mixed feeding after birth, 8 months since the addition of rice cereal, eating cyanosis, 5 months rise, sitting alone for 8 months, usually normal activity, no sweating, no activity after the shortness of breath, cyanosis performance. Non-toxic, radioactive exposure history. Parents are healthy, non-relatives get married, a sister, body health, no family history of genetic disease. Admission examination: body