1 Case abstract rnPatient , female, 33 years old ,got to hospital 1 h after sudden retrosternal pain.The pain was severe and colic at middle upper part of sternum,contiuous and radiating towards precardium,left shoulder,back and upper limb,without dizziness,headache,dyspnea,shortbreath,motion disturbance and mental changes.ECG showed normal,cardiac ultrasound showed dissecting aneurysm of ascending aorta,and large amount of reflux of aorta valve.physical examination:T:36.8 ℃ ,P:82 beats/min,height:178 cm ,weight:58 kg,conscious,stable respiration, thin and long figure,finger distance longer than height, thin subcutaneous fat,light protrusion of eyeball,bad convergence,thyroid II° swelling,quality middle,no node,no touch pain,no vessel murmur heard, flat at chest region, light respiratory sound of both lungs,no dry and moist rales heard, heart rate 84 beats/min, neat rhythm,heart sounds strong, diastolic period murmur at aorta valve region,abdomen soft,no tenderness,liver and spleen not touched,no percussion pain at both kidney region, both lower limbs no edema, normal spinal biological incurvation,long limbs,big hands and feet, relax of knee,elbow,wrist joints, muscle Ⅴ degree,muscle distension normal,both sides of knee reflex (+ ), pathological reflex not initiated. Water hammer pulse(+ ),pistol shot sound (+ ). Accessory examination:blood, urine, stool routine normal,thymoid function normal, X ray of both hands,pelvic and lumbral vertebral showed no bone substances abnormality, B ultrasound of both adrenal gland normal,B ultrasound of thyroid showed multiple space occupying lesion .calcitonin in blood:34 μ g/L (23～ 71 μ g/L),PTH:31 μ g/L(12～ 72 μ g/L),double X ray bone density examination(lunarDPXIQ5689):BMD of lumbral vertebral 0.977 g/cm2,T Score 0.4,Z Score 0.1,indicated bone density decreasing,ultrasound cardiogram showed:dissecting aneurysm of aorta, chest and thoracic aorta MRI showed dissecting aneurysm of ascending aorta.Diagnosis:Marfan syndrom;dissecting aneurysm of ascending aorta;bone density decreasing of lumbral vertebral.Treatment:Bental operation, calcium and VD. rn