:Normal range
IgG1: 65 %, IgG2: 25 %, IgG3: 6%, IgG4: 4%
(IgG Subclass levels (mg/dL
| IgG4 | IgG3 | IgG2 | IgG1 | Age |
| 6-63 | 9-62 | 30-140 | 190-620 | 0-1 y |
| 4-43 | 11-98 | 30-170 | 230-710 | 1-2 y |
| 3-120 | 6-130 | 40-240 | 280-830 | 2-3 y |
| 5-180 | 9-160 | 50-310 | 350-810 | 3-6 y |
| 11-620 | 13-320 | 30-630 | 270-1740 | > 6 y |
Comment: Approximately 80% of total serum immunoglobulin (Ig) in adults is IgG, which is divided into four subclasses on the basis of structural differences in the hinge region. IgG1 and IgG3 are closely related, as are IgG2 and IgG4. impaired synthesis or abnormal loss may cause deficiencies of one or more immunoglobulin subclasses. Selective IgG subclass deficiencies can occur in spite of a normal total IgG level. Study of patients with recurrent bacterial infections. Selective deficiencies maybe found among the subclasses in some individuals who suffer repeated infections, especially IgG1
Sample: serum