BamHI-SacI RFLP and Gm analysis of the immunoglobulin IGHG genes in the Northern Selkups (west Siberia): new haplotypes with deletion, duplication and triplication
Lp. Osipova et al., BamHI-SacI RFLP and Gm analysis of the immunoglobulin IGHG genes in the Northern Selkups (west Siberia): new haplotypes with deletion, duplication and triplication, HUM GENET, 105(6), 1999, pp. 530-541
Gm immunoglobulin allotypes have been studied in 1157 individuals of seven
Northern Selkup populations, which account for 80% of the entire population
of this west Siberian tribe. This study confirms that the northern Selkup
populations are a Caucasoid-Mongoloid hybrid. Restriction fragment length p
olymorphism (RFLP) analysis of the IGHG genes using double BamHI-SacI diges
ts, performed on 475 DNA samples, allowed us to describe nine new BamHI-Sac
I haplotypes (BS47 to BS55), eight of them being characterized by IGHG gene
deletion or duplication: GI (BS49) or G4 (BS55) deletion, G4 duplication (
BS51), GP-G2-G4 multigene deletion (BS50), duplication (BS48, BS53 and BS54
) or triplication (BS52). A new rare Gm haplotype 15,16*;1,17;23 has been f
ound associated with BS52. The BS51 haplotype characterized by a duplicated
G4 gene (additional 7.85 kb G4 band identifying a new G4*C5 allele) was al
ways found associated with the Gm 5*;3;23 haplotype. A high RFLP diversity
has been observed for the Nortern-Mongoloid haplotype Gm 15,16*;1,17;.. whi
ch was found (1) with the BS27 haplotype characterized by a 3-exon hinge G3
gene, (2) with two different GP-G2-G4 multigene duplications, BS53 and BS5
4 haplotypes, which differ by the size of the duplicated G4 genes, and (3)
with the BS55 haplotype characterized by a G4 deletion. In the Northern Sel
kups, haplotypes with duplicated genes were observed at a higher frequency
(24%) than haplotypes with deleted genes (6%).