患儿,男,3岁。因蓝巩膜、骨折就诊。患儿出生后巩膜一直为蓝色。生后第七天因右腿不动,家长轻抬其腿发生骨折,已治愈。1岁零8月会走,步态不稳,易跌跤,曾骨折3次。前2次治愈,此次骨折愈合2月尚不能站立。患儿系第一胎,其母妊娠期健康,无化学药品及放射线接触史。父母非近亲婚配。父亲巩膜也为蓝色,幼年时骨折2次,成人后未发生过骨折,父母家族成员无类似病史。检查发育营养稍差,智力正常,四肢比例匀称,皮肤无异常。前额宽前突,枕骨后突。双眼巩膜呈淡蓝色。乳牙出齐,牙呈淡黄色,无龋齿及断牙。心肺无异常,肝脾不大。双下肢肌肉萎缩,肌张力低下,不能站立。外生殖器无异常。血电解质测定钾4.98mmol/L,钠137mmol/L,钙2.64mmol/L,磷1.7mmol/L,氯100mmol/L,镁0.58mmol/L。碱性磷酸酶16.8~n。X线摄后检查:左腕正位片未见佝偻病征象。双膝臗关节正 Children, male, 3 years old. Blue sclera, fracture treatment. The child’s sclera has been born blue. The seventh day after birth due to the right leg does not move, parents lift their legs fractures, has been cured. 1 year and 0 months in August will go, unsteady gait, easy to fall, had fractures 3 times. The first 2 times cured, the fracture healing in February still can not stand. Children with the first child, his mother’s health during pregnancy, no history of chemical exposure and radiation. Parents non-relatives marriage. His father also sclera blue, fractures in childhood 2 times, no fracture occurred in adults, parents and family members have no similar history. Check the development of nutrition is slightly poor, normal intelligence, well-proportioned limbs, no abnormal skin. Forehead wide anterior process, occiput. Eyes sclera was light blue. Out of primary teeth, teeth pale yellow, no dental caries and broken teeth. No abnormal heart and lung, liver and spleen is not large. Lower extremity muscle atrophy, low muscle tone, can not stand. No abnormal genitalia. Blood electrolytes measured potassium 4.98mmol / L, sodium 137mmol / L, calcium 2.64mmol / L, phosphorus 1.7mmol / L, chlorine 100mmol / L, magnesium 0.58mmol / L. Alkaline phosphatase 16.8 ~ n. X-ray examination: no evidence of rickets in the left wrist. Double knee joint is positive