Patients
The volunteers recruited to the study were aged from 0–18 years; all were from nonconsanguineous families in mainland China, and included premature newborns and low BW newborns. Those with PIDs were admitted to the Children’s Hospital of Chongqing Medical University and diagnosed according to clinical features, laboratory inspection, and genetic analysis. WAS or CGD patients accepted for transplantation were followed up at Children’s Hospital of Chongqing Medical University. Clinical data were collected during hospitalization. Informed consent was obtained from participants or their guardians.