This study aimed to investigate the structural characteristics of the Hb and its functional connectivity (FC) with large-scale brain networks in CID patients.<h4>Methods</h4>A total of 42 CID patients and 31 age-, gender-, and education-matched healthy controls (HC) completed clinical questionnaires, structural magnetic resonance imaging (sMRI) and resting-state fMRI (rs-fMRI).<h4>Results</h4>No significant group differences were observed in the relative volumes or the laterality index between CID patients and HC. The gene discussed is GSTM1; the disease is combined immunodeficiency.