Palmar atd angle greater than 45deg; is a special appearance of mental retardation congenital stupidity due to chromosomal anomalies (sign 21 III, Down syndrome). The symptom is present in approximately 40% of patients. Mental retardation (mentalretardation) is a syndrome characterized by an individual’s intellectual functioning that is significantly lower than that of his or her peers due to mental retardation, impaired or impaired intellectual development, accompanied by difficulties in social adjustment, prior to developmental maturity (usually before the age of 18). The following diseases may also cause palm atd angle greater than 45 ° symptoms: 1, hypertension Hypertension (hypertensive disease) is a kind of arterial blood pressure rises as the main manifestation of chronic diseases, often caused by the heart, the brain, the kidney and other important organs of the lesions and the corresponding consequences. Galactosemia Galactosemia (galactosemia) is a toxic clinical metabolic syndrome in which blood galactose is increased. Galactose metabolism in three kinds of related enzyme in any one of the enzyme congenital defects can cause galactosemia: ① galactose-1-phosphate uridylyltransferase (Gal-1-PUT) defects: this is the classic galactosemia, the more common; ② galactose kinase defects: the more rare; ③ urinary-glycoside diphosphate galactose-4-epiisomerase (UDP-Gal-4-E) defects: rare. 3.Anemia Anemia is a common clinical symptom of human peripheral blood erythrocyte capacity zang less than the lower limit of the normal range. 4, hydrocephalus hydrocephalus is due to intracranial disease caused by excessive secretion of cerebrospinal fluid or (and) circulatory and absorption disorders, resulting in an increase in intracranial cerebrospinal fluid. Clinical children often see skull enlargement, fontanel enlargement, tension and fullness, cranial suture dehiscence healing incompatibility, sunset vision, vomiting, convulsions, speech and movement disorders, mental retardation; adults often see intermittent headache, head swelling, head sinking, dizziness, tinnitus and ear blockage, vision loss, limb weakness, etc. 5, mental retardation Mental retardation (MR) is a group of diseases that occur during the developmental period, the general intellectual functioning is significantly lower than the level of the same age, accompanied by adaptive behavioral deficiencies in the same amount. There are also mental retardation, mental retardation, mental retardation, mental deficiency, intellectual backwardness, intellectual disability, mental retardation, mental retardation, mental retardation, mental retardation and intellectual disability and so on. 6, epidemic B encephalitis epidemic B encephalitis (hereinafter referred to as B encephalitis) pathogen found in Japan in 1934, so the name of the Japanese B encephalitis, 1939, China also isolated to the B encephalitis virus, the liberation of a large number of investigations and research, renamed as epidemic B encephalitis. This disease is mainly distributed in the Far East of Asia and Southeast Asia, transmitted by mosquitoes, mostly in summer and fall, clinically acute onset, high fever, impaired consciousness, convulsions, tonic spasms and meningeal irritation, etc., and heavy patients often have sequelae after the disease.