A, the etiology of precocious heart disease: so far not clear II, factors affecting the formation of precocious heart disease: 1, genetic defects: microscopic molecular level precocious heart disease gene deletion related. 2, hypoxia: the incidence of precocious heart disease in highland areas is 0.7% ~ 1.34%. 3, genetic: the incidence is about 2% ~ 4% higher with family history. 4, viral infection: rubella infection in the first trimester of pregnancy (especially the first four weeks). 5, the role of drugs: aminoglycoside antibiotics (such as streptomycin, etc.). 6, environmental pollution: air, water, soil pollution; ionizing radiation. 7, combined with other: malnutrition, anemia, parental smoking and alcohol consumption, heart, vascular malformation.