患者,男,年龄15岁,农民,其弟年龄12岁,两人均系足月顺产,母乳喂养,2岁余断乳。幼儿时开始说话,会走、会跑时间与一般儿童无异,至8岁时无原因逐渐不会跑,只会走,至12岁时行走缓慢,摇晃,呈鸭步,蹲后不能起立,需以两手支撑,足、踝、膝部顺次向上攀扶才能立起。因此不能参加劳动,七岁入学读书,两人成绩均不良,均留级一次。查体:患 Patient, male, age 15, farmer, his younger brother 12 years old, both of them were in full-term follow-up, breastfed and over 2 weaned. Toddler began to speak, will go, will run the time is no different from children in general, to the age of 8 no reason will gradually not run, will only go to 12-year-old walking slowly, shaking, duck steps, can not stand after squatting, Need to support both hands, feet, ankles, knees in order to climb upward to build up. Therefore, they can not participate in work. At the age of seven, they both have poor grades and both have grades. Physical examination: suffering