A Study to Evaluate the Efficacy and Safety of Recombinant Human Growth Hormone Injection in Patients With Prader-Willi Syndrome

Inclusion Criteria: * 1.Signed informed consent from legal guardian of the subjects; * Subjects are willing and able to cooperate to complete scheduled visits, treatment plans and laboratory tests and other procedures; * Diagnosed as PWS by gene test; * Age: 1 month (30 days after birth) - 5 years of age; * Male or female; * Calculated by Peabody Developmental Motor Scale, total motor quotient, gross motor quotient or fine motor quotient is less than 90 points; * Thyroid function is within the normal reference range or remained within the normal reference range by substitution therapy; * No history of rhGH therapy before. Exclusion Criteria: * Subjects with abnormal liver or kidney function; * Subjects with obvious central sleep apnea and/or moderate or severe obstructive sleep apnea, acute lung infection; * Subjects with chronic diseases that have long-term effects on bone metabolism and body composition; * Subjects with congenital skeletal dysplasia, or spine scoliosis with moderate and above degree requiring treatment or lameness; * Subjects with history of congenital heart disease, or an echocardiogram showing that the structural abnormalities require surgery or interventional therapy or that the left ventricular ejection fraction is \<40%, or the abnormal electrocardiogram requiring intervention; * Subjects with history of convulsions or epilepsy; * Subjects with other systemic chronic diseases; * Subjects with diagnosed tumors; * Subjects with family history of cancers, a previous history of cancer, or considered to be a high risk of cancer combinating other information; * Subjects with mental disease; * Subjects with diabetes, or abnormal fasting glucose and researchers believe that may affect the safety of the subject; * Subjects with severe obesity; * Subjects with highly allergic constitution or allergy to proteins or investigational product or its excipient; * Subjects who took part in other clinical trials within 3 months ; * Subjects who received drug treatment that may interfere with GH secretion or GH action within 3 months; * Other conditions in which the investigator preclude enrollment into the study