Restriction fragment length polymorphisms (RFLPs) have been described for all IGHG genes (G3, G1, GP, G2, G4) using various restriction endonucleases (BamHI, SacI, BamHI/SacI, EcoRI, BstEII) and IGHG gene probes [1-9]. The most informative RFLP analysis for population genetics studies are double BamHI-SacI digests producing polymorphic bands for the five IGHG genes [6, 7]. The designation of the restriction fragments allowing to define the different BamHI-SacI RFLP alleles also designated as C* alleles (Table 1). The restriction fragments are transmitted in combinations or linkage groups designated BS (BamHI/SacI) haplotypes (Table 2).

Probes: pSH3Cgamma3 clone [8]
pSgamma3h clone [9]

Table 1. BamHI-SacI RFLP alleles and sizes of the corresponding restriction digest fragments.

Reference for this table: Osipova et al., 1999 [7]

BamHI-SacI RFLP alleles
(C* alleles)		 Ghanem et al.,
1988 [1]		 Ghanem et al.,
1989 [4]		 Dard et al.,
1996 [6]		 Osipova et al.,
1999 [7]
G3*C1 6.5 6.5 6.9, 6.95 6.9
G3*C2 6.3 6.3 6.7 6.7
G3*C3 5.9 5.9 6.5  
G3*C4 6.9a 6.9a 7.3  
G3*C5b   6.35a 6.75  
G3*C6     1.9  
G1*C1 8.8 8.8 9.1, 9.15 9.1
G1*C2   8.6a 8.9  
G1*C3   8.5a 8.7  
G1*C4   8.3a 8.5  
G1*C5     3.7  
GP*C1 9.4 9.4 9.7 9.7
GP*C2 8.2 8.2   8.5
G2*C1 7.5 7.5 7.6 7.6
G2*C2 7.0 7.0 7.3 7.3
G4*C1 7.6 7.6 8.0 7.9
G4*C2 7.4 7.4 7.8  
G4*C3 7.2 7.2 7.7 7.7
G4*C4 4.2+3.2 4.2+3.2 3.5  
G4*C5       7.85

Sizes of the BamHI-SacI (C* alleles) restriction fragments are shown in kilobases. For BamHI (A* alleles) and SacI (B* alleles) restriction fragments, see [1, 3].
a Fragments found only in Black African individuals or in persons with Negroid Gm haplotypes.
b Except if mentioned, G3*C5 allele is not differentiated from G3*C2.

Table 2. BS haplotypes and BamHI-SacI RFLP alleles.

Twenty-seven BS haplotypes were originally defined taking into account together fragments resulting from BamHI-SacI double digests, from BamHI, and from SacI single digests [2, 3]. For practical reasons, more recent studies [6, 7] only consider BamHI-SacI double digests. According to these new rules four BS haplotypes BS14, BS16, BS20, and BS26 (in parentheses in the table) which were previously differentiated from BS1, BS6, BS15, and BS23, respectively, by their BamHI or SacI fragments are not individualized any more. The numbers 14, 16, 20, and 26 are left unused to avoid conflict with previous publications. Haplotypes with G1 and G3 deletion, described in [1], have been assigned to BS28 and BS29, respectively. New haplotypes described in [6, 7], following analysis by M.-P. Lefranc have been assigned to BS30 to BS46. New haplotypes from [7] correspond to BS47 to BS55. In the description of the BamHI-SacI (BS) RFLP genotypes and haplotypes, alleles are written in the linkage order of the IGHG genes, i.e., G3, G1, GP, G2 and G4, with dots separating the alleles. For instance, the BS8 haplotype (G3*C1, G1*C1, GP*C1, G2*C2, G4*C3) is described as 1.1.1.2.3. [2]. Gene deletions are shown by zero (0); 2 or 3 numbers for the same gene indicate duplication or triplication, respectively.

BS haplotypes BamHI-SacI RFLP alleles
(C* alleles)
G3.G1.GP.G2.G4.
BS1(14) 1.1.2.1.3.
BS2 2.1.2.1.3.
BS3 1.1.2.1.1.
BS4 1.1.2.1.2.
BS5 2.1.1.2.1.
BS6(16) 1.1.1.2.1.
BS7 1.1.1.1.2.
BS8 1.1.1.2.3.
BS9 2.1.2.1.1.
BS10 2.1.1.1.2.
BS11 2.1.1.2.2.
BS12 1.1.1.1.1.
BS13 2.1.1.2.4.
BS15(20) 1.1.1.2.2.
BS17 1.2.1.2.1.
BS18 1.2.1.2.2.
BS19 1.1.1.1.3.
BS21 1.3.1.2.1.
BS22 1.3.1.2.2.
BS23(26) 2.2.1.2.2.
BS24 2.3.1.2.2.
BS25 4.4.1.1.3.
BS27 2.1.1.2.3.
BS28 1.0.1.2.1.
BS29 0.1.1.2.1.
BS30 1.0.2.1.2.
BS31 1.2.1.2.3.
BS32 1.3.1.2.3.
BS33 1.33.1.2.1.
BS34 2.2.1.1.1.
BS35 2.2.1.2.3.
BS36 2.3.1.2.4.
BS37 2.5.1.1.1.
BS38 2.5.1.1.3.
BS39 2.5.1.2.3.
BS40 3.1.1.1.1.
BS41 4.1.1.2.3.
BS42 4.4.1.2.3.
BS43 6.11.1.1.1.
BS44 6.1.1.2.3.
BS45 6.3.1.2.2.
BS46 6.3.1.2.3.
BS47 1.1.2.2.3.
BS48 1.1.11.22.33.
BS49 1.0.1.2.3.
BS50 1.1.0.0.0.
BS51 1.1.2.1.15.
BS52 2.1.112.221.335.
BS53 2.1.11.22.13.
BS54 2.1.11.22.33.
BS55 2.1.1.2.0.

References:

[1] Ghanem, N. et al., Eur. J. Immunol., 18, 1059-1065 (1988).
[2] Ghanem, N. et al., Eur. J. Immunol., 18, 1067-1072 (1988).
[3] Ghanem, N. et al., Hum. Genet., 83, 37-44 (1989).
[4] Ghanem, N. et al., Exp. Clin. Immunogenet., 6, 39-54 (1989).
[5] Lefranc, M.-P. and Lefranc, G., In: Shakib F (ed) The human IgG subclasses: molecular analysis of structure, function and regulation. Pergamon, Oxford, pp. 43-78 (1990).
[6] Dard, P. et al., Hum. Genet., 98, 36-47 (1996).
[7] Osipova, L.P. et al., Hum. Genet., 105, 530-541 (1999).
[8] Huck, S. et al., Nucleic Acids Res., 14, 1779-1789 (1986).
[9] Huck, S. et al., FEBS Lett., 208, 221-230 (1986).

Created: 15/12/2000
Authors: Olga Posukh, Gérard Lefranc, Marie-Paule Lefranc