Fig. 1

Pedigree of family S12. Affected family members are identified by solid squares or circles. Each individual is identified by generation (I–V), consecutively within each generation (e.g., generation II. 1-12), and by an “s” if a spouse. The MHC haplotype of the individual is shown underneath his or her pedigree symbol. Complete copies of haplotype 1 are identified as “a” through “h”, and the three different fragments as χ, χ², and χ³ Haplotypes other than copies of haplotype 1 are designated by a dash. In S12.IV.18 and S12.IV.19, we cannot determine whether the a or g copy of haplotype 1 was inherited from their father, S12.III.8, hence the “a?g” haplotype designation. For immunodeficient individuals, serum immunoglobulin concentrations in mg/dl are shown in the order IgM, IgG, and IgA.