患儿 ,男 ,9岁 ,出生后一直腹胀 ,便秘 ,伴腹痛 ,排便、排气困难 ,腹胀以餐后明显 ,大便 2～ 3ｄ 1次 ,因症状渐加重而入院就诊。患儿为第 1胎 ,足月产出生 ,双亲非近亲结婚 ,均身体健康。体检 :智能低下 ,发育迟缓 ,营养欠佳 ,头发细、少而软 ,眼距宽 ,眼裂小 ,虹膜边缘可见白 Children, male, 9 years old, have been bloating after birth, constipation, with abdominal pain, defecation, exhaust difficulties, abdominal distention to postprandial stool, stool 2 ~ 3d 1 times, due to progressive symptoms and hospitalization. Children with first birth, full-term birth, parents marry non-relatives, are in good health. Physical examination: mental retardation, stunting, poor nutrition, thin hair, less and soft, wide ocular distance, small eyelid, visible white edge of iris