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Introduction

The human genome comprises a total number of 608-665 IG and TR genes (371-422 IG and 237-243 TR), depending on the haplotypes, per haploid genome of which 531-588 genes are located in the 7 major loci (distributed in 369-418 V, 32 D, 105-109 J and 25-29 C genes). There are also 77 orphons (68 IG and 9 TR) (including two processed IG genes which are IGHEP2 and IGLJ-C/OR18), outside the major loci.

Major loci Orphons Total number of IG and TR genes including orphons
Locus size (Kb) V D J C Total number of genes [1] [2] V D J C Total number of genes
IG 2800-4120 236-279 27 21-25 19-23 303-354 54 10 0 4 68 371-422
TR 1840 133-139 5 84 6 228-234 9 0 0 0 9 237-243
Total number of IG and TR genes per haploid genome 369-418 32 105-109 25-29 531-588 63 10 0 4 77 608-665

The number of functional IG and TR genes is 308-356 (136-171 IG and 172-185 TR) per haploid genome. They comprise 174-219 V, 28 D, 86-88 J and 20-21 C genes.

Locus size (kb) V D J C Number of functional IG and TR genes [1] [2]
IG 2800-4120 84-117 23 15-16 14-15 136-171
TR 1840 90-102 5 71-72 6 172-185
Total number of functional IG and TR genes per haploid genome 174-219 28 86-88 20-21 308-356

Total number of IG and TR genes, per haploid genome.

The IG genes

The human genome comprises 371-422 IG genes (303-354 genes located in the 3 major IG loci and 68 orphons), per haploid genome.

Citing this table: FactsBook IG and this page.

Locus Major loci Number of orphons Total number of IG genes including orphons
Chromosomal localization V D J C Total number of genes [1]
IGH 14q32.33 123-129 27 9 11a 170-176b 36c 206-212b,c
IGK2p11.2 (40d or) 76 0 5 1 (46d or) 82 25 (71d or) 107
IGL22q11.2 73-74 0 7-11 7-11 87-96 7e 94-103
Total number of genes 236-279 27 21-25 19-23 303-354 68c,e 371-422c,e

a Allelic IGHC multigene deletions (for review [3]), duplications and triplications have been described in healthy individuals. The number of IGHC genes may vary from 5 (deletion I) to probably 19 (triplication III) per haploid genome. See references in Locus representation: Human (Homo sapiens) IGH.
b Not included the 7 non-mapped IGHV genes.
c Included the IGHC processed gene, IGHEP2, localized on chromosome 9 (9p24.2-24.1).
d Number of genes in the rare IGKV haplotype without the distal V-CLUSTER.
e Included the IGLJ-C/OR18 processed gene, localized on chromosome 18 (18p11.31).

The TR genes

The human genome comprises 237-243 TR genes (228-234 genes located in the 4 major TR loci and 9 orphons), per haploid genome.

Citing this table: FactsBook TR and this page.

Locus Major loci Number of orphons Total number of TR genes including orphons
Chromosomal localization V D J C Total number of genes [2]
TRA14q11.2 54a 0 61 1 116a 0 116a
TRB7q34 64-67 2 14 2 82-85 9 91-94
TRG7p14 12-15 0 5 2 19-22 0 19-22
TRD14q11.2 3 (8a) 3 4 1 11 (16a) 0 11 (16a)
Total number of genes 133-139 5 84 6 228-234 9 237-243

a Including the 5 TRAV/DV genes. In "Total number of genes", these 5 genes are only counted once.

Number of functional IG and TR genes per haploid genome

Functional IG genes

The functional IG genes (136-171 depending on the haplotypes) are located in the 3 major IG loci.

Citing this table: FactsBook IG and this page.

Locus Chromosomal localization Locus size (kb) V D J C Number of functional IG genes [1] Combinatorial diversity (range per locus)
Minimum Maximum
IGH 14q32.33 1250 38-46 23 6 9a 76-84 38 x 23 x 6 = 5244 46 x 23 x 6 = 6348
IGK 2p11.2 1820 34-38 0 5 1 40-44 34 x 5 = 170 38 x 5 = 190
500 17-19b 23-25b 17 x 5 = 85b 19 x 5 = 95b
IGL 22q11.2 1050 29-33 0 4-5 4-5 37-43 29 x 4 = 116 33 x 5 = 165
Total number of functional genes 2800-4120 101-117 23 15-16 14-15 136b-171
84-98b

a In haplotypes with multigene deletion (for review [3]), the number of functional IGHC genes is 5 (deletions I, III, and V), 6 (deletions IV and VI), or 8 (deletion II), per haploid genome. In haplotypes with multigene duplication or triplication, the exact number of functional IGHC genes per haploid genome is not known. See references in Locus representation: Human (Homo sapiens) IGH.
b In one rare haplotype, the number of IGKV genes is 17-19 on 500 kb.

Functional TR genes

The functional TR genes (172-185 depending on the haplotypes) are located in the 4 major TR loci.

Citing this table: FactsBook TR and this page.

Locus Chromosomal localization Locus size (kb) V D J C Number of functional TR genes [2] Combinatorial diversity (range per locus)
Minimum Maximum
TRA 14q11.2 1000 43-45a 0 50 1 94-96a 44 x 50 = 2200 46 x 50 = 2300
TRB 7q34 620 40-48 2 12-13 2 56-65 40 x 2 x 12 = 960 48 x 2 x 13 = 2300
TRG 7p14 160 4-6 0 5 2 11-13 4 x 5 = 20 6 x 5 = 30
TRD 14q11.2 60b (530c) 3 (7-8a) 3 4 1 11 (15-16a) 3 x 3 x 4 = 36 8 x 3 x 4 = 96a
8 x 7 x 4 = 224d
Total number of functional genes 1840 90-102 5 71-72 6 172-185

a Including 5 TRAV/TRADV genes. The number of functional TRAV and TRDV genes in the TRA/TRD locus is 46-48. The total number of the functional genes for the TRA/TRD locus is 105-107.
b Size of the cluster from TRDV2 to TRDV3.
c Distance between the most 5' TRAV/DV gene (TRAV14/DV4) and the most 3' gene of the TRD locus (TRDV3).
d Taking into account the rearrangement with 2 or 3 TRDD (4 possible combinations: D1,D2; D1,D3; D2,D3; D1,D2,D3).

Number of genes in the IMGT genome analysis tools

IMGT genome analysis tools provide information on a clone contig for a given IG, TR or MHC locus. This information is of interest to give a graphical representation of the locus organization. The clone accession numbers provided do not necessarily correspond to IMGT reference sequences (available in IMGT/GENE-DB and in IMGT Repertoire).

Human (Homo sapiens) IG genes

Human IGK locus
IMGT/GeneSearch
IMGT/GeneView
IMGTLocusView 		Clones containing the IGK locus Locus size Number of genes in the clones
IGKV IGKJ IGKC
76 5 1
AP001214-AP001215 1820 kb F ORF P F ORF P F ORF P
33 10 33 5 0 0 1 0 0
Human IGL locus
IMGT/GeneSearch
IMGT/GeneView
IMGTLocusView 		Clones containing the IGL locus Locus size Number of genes in the clones
IGLV IGLJ IGLC
74 7 7
D86993-D87017 1050 kb F ORF P F ORF P F ORF P
33 6 35 5 2 0 5 0 2
Human IGH locus
IMGT/GeneSearch
IMGT/GeneView
IMGTLocusView 		Clones containing the IGH locus Locus size Number of genes in the clones
IGHV IGHD IGHJ IGHC
123 27 9 11
AB019437-AC084717
J00222, J00221 and M60194 		1250 kb F ORF P F ORF P F ORF P F ORF P
46 3 36 23 4 0 6 0 3 9 1 1

Human (Homo sapiens) TR genes

Human TRA locus
IMGT/GeneSearch
IMGT/GeneView
IMGTLocusView
IMGT/GeneInfo
Clones containing the TRA locus Locus size Number of genes in the clones
TRAV TRAJ TRAC
54a 61 1
AE000658-AE000662 1000 kb F ORF P F ORF P F ORF P
45a 1 8 50 8 3 1 0 0

a Included the 5 TRAV/DV genes.

Human TRD locus
IMGT/GeneSearch
IMGT/GeneView
IMGTLocusView
IMGT/GeneInfo 		Clones containing the TRD locus Locus size Number of genes in the clones
TRDV TRDD TRDJ TRDC
3 3 4 1
AE000659-AE000661 550 kbb F ORF P F ORF P F ORF P F ORF P
3 (8)a 0 0 3 0 0 4 0 0 1 0 0

a Included the 5 TRAV/DV genes.
b 550 kb from TRAV14/DV (the TRAV/DV gene the most in 5') to TRDV3 (the TRD gene the most in 3').

Human TRB locus
IMGT/GeneSearch
IMGT/GeneView
IMGTLocusView
IMGT/GeneInfo
Clones containing the TRB locus Locus size Number of genes in the clones
TRBV TRBD TRBJ TRBC
67 2 14 2
L36092 620 kb F ORF P F ORF P F ORF P F ORF P
47 6 14 2 0 0 13 1 0 2 0 0
Human TRG locus
IMGT/GeneSearch
IMGT/GeneView
IMGTLocusView
IMGT/GeneInfo 		Clones containing the TRG locus Locus size Number of genes in the clones
TRGV TRGJ TRGC
14 5 2
AF159056 160 kb F ORF P F ORF P F ORF P
6 3 5 5 0 0 2 0 0
More information:
References:
[1] Lefranc, M.-P. and Lefranc, G., The Immunoglobulin FactsBook, Academic Press, 458 pages (2001) ISBN:012441351X.
[2] Lefranc, M.-P. and Lefranc, G., The T cell receptor FactsBook, Academic Press, 398 pages (2001) ISBN:0124413528.
[3] Wiebe, V. et al., Human Genetics, 93, 520-528 (1994).
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