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G1m allotypes

G1m17 and G1m3

G1m17 or G1m(z) corresponds to IGHG1 CH1 [Lys(K)120, a359] according to the IMGT unique numbering for C-DOMAIN [1] (Exon numbering 97 [2], Eu numbering 214 [3]).
This allotype is found on alleles IGHG1*01 and IGHG1*02 [2,4].

G1m3 or G1m(f) corresponds to IGHG1 CH1 [Arg(R)120, g359].
This allotype is found on allele IGHG1*03 [4].
The Arg(R)120 is also found on IGHG3 and IGHG4 and is responsible of the iso-allotype nG1m17 present on IGHG1 G1m3, IGHG3 and IGHG4 [5].

G1m1 and nG1m1

G1m1 or G1m(a) corresponds to IGHG1 CH3 [Asp(D)12, t36; Leu(L)14, c40] according to the IMGT unique numbering for C-DOMAIN [1] (Exon numbering 16 and 18 [2], Eu numbering 356 and 358 [3]).
This allotype is found on alleles IGHG1*01 and IGHG1*02 [4].

nG1m1 or nG1m(a) corresponds to IGHG1 CH3 [Glu(E)12, g36; Met(M)14, a40].
This allotype is found on allele IGHG1*03 [2,4].

G1m2 and nG1m2

G1m2 or G1m(x) corresponds to IGHG1 CH3 [Gly(G)110, g329] according to the IMGT unique numbering for C-DOMAIN [1] (Exon numbering 91, Eu numbering 431 [3]).
This allotype is found on allele IGHG1*04 (G.Lefranc and M.-P. Lefranc, personal communication).

nG1m2 or nG1m(x) corresponds to IGHG1 CH3 [Ala(A)110, c329].
This allotype is found on alleles IGHG1*01, IGHG1*02 and IGHG1*03 [4].

IGHG1*01 and IGHG1*02 are G1m1,17 (previously written G1m1,17).
IGHG1*03 is G1m3 (previously written Gm3).
IGHG1*04 is G1m1,2,17 (previously written G1m1, 2, 17).

Amino acid positions (1)
CH1 CH3
G1m alleles IGHG1 allele names 120 12 14 110
(97) (16) (18) (91)
214 356 358 431
G1m1,17 IGHG1*01
IGHG1*02		 Lys
AAA		 Asp
GAT		 Leu
CTG		 Ala
GCT
G1m3 IGHG1*03 Arg
AGA		 Glu
GAG		 Met
ATG		 Ala
GCT
G1m1,2,17 IGHG1*04 (2) (Lys)
(AAA)		 (Asp)
(GAT)		 (Leu)
(CTG)		 Gly
(GGT)
IMGT notes:
(1) Amino acid numbering in bold is according to IMGT unique numbering for C-DOMAIN [1], between parentheses: exon numbering [2] and in italics: Eu numbering [3].
(2) IGHG1*04 amino acid and codon between parentheses are expected (G. Lefranc and M.-P. Lefranc) [2,5] but not yet sequenced at the nucleotide level and therefore the IGHG1*04 allele is not shown in Alignments of alleles: IGHG1.
IMGT references:
[1] Lefranc, M.-P. et al., Dev. Comp. Immunol., 29, 185-203 (2005). PMID: 15572068 pdf with permission from Elsevier
[2] Lefranc G. and Lefranc M.-P. The Immunoglobulin FactsBook, Academic press, London, UK, 458 pages (2001).
[3] Correspondence between C numberings (in IMGT Scientific chart).
[4] Alignment of alleles: Human IGHG1 (in IMGT Repertoire).
[5] Lefranc G. PhD Thesis. Allotypes et haplotypes des immunoglobulines dans les communautés libanaises: intérêt exceptionnel en immunogénétique et séro-anthropologie (in French). Immunoglobulin allotypes and haplotypes in the Lebanese communities : discussion of unusual genetic events and population structure (in English) Université de Rouen (1978).