Efficacy and Safety of rhGH (Jintropin®) in Pediatric Participants With ISS

Inclusion Criteria: * Boys are between 4 and 10 years old age and girls are between 4 and 9 years old age; * Height \<-2.25 SD (Standard deviation) for chronological age; * GH (Growth hormone) peak concentration ≥10.0 ng/mL in GH stimulation tests; * The bone age (BA) ≤chronological age (CA)+6 months; * Prepubertal Status (Tanner Stage I); * Birth weight within the normal range; * Growth hormone treatment-naive; * Participants are willing and able to cooperate to complete scheduled visits, treatment plans and laboratory tests and other procedures, to sign informed consent. Exclusion Criteria: * Participants with abnormal liver and kidney functions (ALT \> upper limit 1.5 times of normal value; Cr \> upper limit of normal value); * Participants are positive for anti-HBc, HbsAg or HbeAg in Hepatitis B virus tests; * Participants with known highly allergic constitution or allergy to investigational product or its excipient; * Participants with systemic chronic disease and immune deficiency; * Participants diagnosed with tumor, or with potential high tumor risks such as tumor markers exceed normal range and some other relative information may be excluded from the treatment; * Participants with mental disease; * Participants with other types of abnormal growth and development; 1. Growth hormone deficiency (GHD) (confirmed by GH stimulation test); 2. Turner syndrome (confirmed by karyotype test of girls); 3. Noonan syndrome (hypertelorism, pectus carinatum, hypophrenia, frequently with skin disease and congenital heart disease, missense mutation of the protein tyrosine phosphatase, non-receptor type 11 (PTPN11) gene on chromosome 12 for half of the participants, for both male and female participants); 4. Laron syndrome (confirmed by IGF-1 generation test); 5. Small for gestational age ( the birth height or weight is below the tenth percentile or 2 SD, with catch-up growth uncompleted at 2 years old); 6. Growth disorders caused by malnutrition or hypothyroidism (thyroid function test). * Participants with impaired glucose regulation (IGR) (including impaired fasting glucose (IFG) and/or impaired glucose tolerance (IGT) ) or diabetes; * BMI (Body mass index) ≥22kg/m²; * Congenital skeletal abnormalities or scoliosis, claudication; * Participants who took part in other clinical trials within 3 months; * Participants who received medications which may interfere GH secretion or GH function, or other hormones within 3 months (such as sex steroids, glucocorticoids, etc.); * Other conditions which is inappropriate for this study in the opinion of the investigator.