A palmar atd angle greater than 45deg; is a specific appearance of mental retardation congenital dysgenesis (21 III sign, Down syndrome) due to chromosomal abnormalities. This symptom is present in approximately 40% of patients. Mental retardation (mentalretardation) is a syndrome in which an individual’s intellectual functioning is significantly lower than that of his or her peers due to mental retardation, impaired or blocked intellectual development before maturity (usually before the age of 18), accompanied by difficulties in social adaptation as the main feature. The causes of mental retardation are both genetic and environmental, and once it occurs, it is difficult to reverse, so prevention should be emphasized. Monitoring of genetic disorders, perinatal care, prevention and early treatment of central nervous system disorders are important preventive measures. In some developed countries, blood biochemical screening for several genetic metabolic disorders is implemented for all newborns according to specific laws, providing conditions for early prevention and treatment. In the diet, we should eat more vegetables and fruits, especially dark vegetables; appropriately increase the intake of seafood, such as kelp, nori, and marine fish; eat more potassium-rich foods; it is advisable to eat calcium-rich foods; eat more vitamin C-rich foods. The following foods are recommended to eat in moderation: 1, celery celery belongs to the crude fiber-rich vegetables, but also the public’s daily life of common vegetable varieties, can lower blood pressure, regulate blood pressure, in addition to lowering blood lipids, permeability and the role of moisture. Celery with roots 120 grams, japonica rice 250 grams. Wash the celery and cut it into six-minute long pieces, and clean the japonica rice. The celery, japonica rice into a pot, add water to the appropriate amount, boil with the fire and then turn to the fire stew until the rice rotten into porridge, and then add a little salt and monosodium glutamate, stir well is ready. 2, hawthorn This product contains a lot of vitamin C, nicotinic acid, etc., has a protective effect on blood vessels. It can lower blood fat and blood pressure. Make homemade hawthorn food or make water to drink. Can also be eaten raw or use sugar hawthorn products. 3, fruit Apples are rich in organic acids, fructose, pectin, fiber and lithium, bromine, zinc and other trace elements. It has the function of preventing vascular sclerosis, atherosclerosis and coronary heart disease. People who eat one or two apples a day, their blood cholesterol content can be reduced by more than 10%. 4, bananas rich in potassium, can buffer the harmful effects of sodium, reduce blood volume and lower blood pressure. Although bananas are good, you can only eat 2 a day, more than not absorbed and a little waste. 5, milk Dairy products can supplement calcium, can effectively lower blood pressure. The calcium in milk will do a combination with sodium, which may help in blood pressure control. The daily intake of 400 ml of low-fat dairy products can effectively control blood pressure. It’s the “calcium” in milk that does the job.