Bird D, Duffy S, Isaacs D, Webster A D
Arch Dis Child. 1985 Mar;60(3):204-7. doi: 10.1136/adc.60.3.204.
A normal range for IgG1, IgG2, and IgG3 subclasses has been established for children aged 6 months to 5 years using commercially available monoclonal antisera. Of particular interest were the very low concentrations of IgG2 in some healthy children, a finding which casts doubt on the importance of IgG2 deficiency reported in some patients with otherwise unexplained infections. It was not possible to construct a normal range for IgG4 values probably because these segregate into two populations in normal subjects.