The convex palate is the clinical manifestation of the skull lesion in Marfan syndrome. It is inherited in an autosomal dominant fashion. Let’s take a look at the differential diagnosis of this disease. 1, tall and thin body with elongated limbs, especially forearms and thighs (1) height more than 180 cm; (2) finger distance height (hands flat, two middle fingers distance – height 7.6 cm, diagnostic value); (3) lower body (from the pubic symphysis to the sole of the foot) upper body (from the top of the head to the pubic symphysis), the ratio of 0.92 (0.92 in normal people). 2, spider fingers / toe-like changes (1) fingers (toes) is particularly long, a typical spider-like changes, hand to height ratio of 11%, foot to height ratio of 15%; (2) thumbsign (thumbsign): thumbs inward, the remaining four fingers clenched fist, the tip of the thumb beyond the lower edge of the palm, accounting for about half of the patients with this disease has this sign; (3) wristsign (wristsign): with one hand clenched (3) Wristsign: when holding the other hand below the radial styloid process, the thumb and little finger can be in contact without pressure, accounting for 82% of patients with this sign; (4) metacarpal index and finger bone index are increased, the metacarpal index of normal people is 8.4 (8.4-10.5). (5) Other finger (toe) anomalies: pestle finger, finger (toe) webbing, thin palm, flat foot may be present. (3) Skull lesions (1) long head, narrow face, convex palate; (2) cranial index 75.9; (3) wide or narrow distance between eyes, long jaw; (4) uneven teeth, lack of wisdom teeth, etc.; (5) both ears protruding or drooping, thin ear whorl, shaped like the elderly. (4) deformity of the chest and spine (1) chicken chest, flat chest, funnel chest; (2) hunchback, lateral protrusion of the spine or spina bifida.