High palatal arches are most often seen in Marfan’s syndrome, a condition resulting from a dominant genetic disorder caused by an autosomal abnormality. Patients are generally normal at birth, but show dysfunction of body organs under normal living conditions. The main features are elongated limbs, spider fingers (toes), arms extended flat with finger spacing greater than body length, hands hanging down past the knees, and upper body longer than the lower body. Cardiovascular lesions mainly invade the aorta, aortic valve and mitral valve, and are the main cause of death. Since this disease is very characteristic, it can be said to be instantly recognizable. Equine Fang syndrome presents with a long head deformity, narrow face, high palatal arch, and large and low ears. There is little subcutaneous fat, underdeveloped muscles, and wrinkled skin on the chest, abdomen, and arms. The disease is evidenced by a chain of genetic locus dominant inheritance in the family, as evidenced by increased urinary hydroxyproline excretion in the patient, and is an elastin fiber deficiency, also known as an abnormality of collagen metabolism. In case of high palatal arch, the following tests should be done: 1. X-ray examination (1) Elongated finger bones. (2) Metacarpal index measurement, the average length of the four metacarpals of the index finger, middle finger, ring finger and little finger divided by the average width of the middle of the four metacarpals on the X-ray posterior anterior film of both hands. (3) Finger bone index measurement, that is, the ratio of the length and width of the proximal phalanges of the right ring finger, female > 4.6, male > 5.6, can diagnose the disease. (4) Aortic root index (4) The width of the aortic root is significantly dilated. Retrograde aortography shows vase-like dilatation of the ascending aorta and enlargement of the left ventricle. 2.CT and or MRI examination can clearly detect the presence of aortic lesions, vessel wall thickness, separation and tearing of aortic coarctation, and occlusion in the lumen. 3.Electrocardiogram can show the manifestations of left ventricular hypertrophy, heart conduction block and myocardial ischemia, etc. 4.Slit lamp examination It can reveal lens dislocation. 5.Measurement of 24h urinary hydroxyproline Increased urinary excretion of hydroxyproline and excessive hyaluronic acid in urine. Regarding the determination of 24h urinary hydroxyproline some scholars suggest it as a diagnostic indicator. The results of 24h urinary hydroxyproline in normal adults and pediatric patients in the data of Tongji Medical University in China were (24.41±17.02) mg, and in patients (including adults and pediatric patients) were (44.84±36.12) mg both differences were very significant. Although this test has poor specificity and low sensitivity, it is meaningful for diagnosis if its value is significantly higher, except for diseases and other factors that can affect the value of urinary hydroxyproline test.