HLA-A69

HLA-A69 (MHC Class I, A cell surface antigen)
HLA-A69
-
Protein	transmembrane receptor/ligand
Structure	αβ heterodimer
Subunits	HLA-A*69--, β2-microglobulin
Older names	"A28"
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subtype	allele	Available structures
A69	*6901
Alleles link-out to IMGT/HLA database at EBI

HLA-A69 (A69) is a human leukocyte antigen serotype within HLA-A serotype group. The serotype is determined by the antibody recognition of α⁶⁹ subset of HLA-A α-chains. For A69, the alpha "A" chain are encoded by the HLA-A*69 allele group and the β-chain are encoded by B2M locus.^[1] This group currently is dominated by A*6901. A69 and A*69 are almost synonymous in meaning. A69 is a split antigen of the broad antigen serotype A28. A69 is a sister serotype of A68.

A69 is more common in Levant. A69 (A*6901) is a derivative of the A*6801 allele that has undergone gene conversion with A*02. The recombination took place no more than 330,000 years ago^[2].

Serotype

A69 recognition of some HLA A*69 gene products^[3]

A*69	A69	A28	A68	A2	Sample
allele	%	%	%	%	size (N)
*6901	7	56	3	6	289

A69 is poor, with low specific detection, high non-specific identification by A28, and false recognition by A68 and A2.

Distribution

HLA A*6901 frequencies

		freq
ref.	Population	(%)
[4]	Palestinian (Gaza)	4.8
[5]	North Isl. (Cape Verde)	4.0
[6]	Druse-Arab (Israel)	3.0
[5]	South Isl. (Cape Verde)	2.4
[7]	Mossi (Burkino Faso)	1.9
[8]	Bulgaria	1.8
[9]	Jew (Israel)	1.2
[10]	Tunis (Tunisia)	1.1
[11]	Bergamo (Italy)	1.1
[12]	N. Delhi (India)	1.1
[13]	Amman (Jordon)	1.0
[14]	Sardinia (Italy)	1.0
[15]	Central Portugal	1.0
[15]	Shanghai (China)	0.7
[16]	Girona (Catalon, Spain)	0.6
[17]	Baloch (Iran)	0.6
[15]	Greece	0.6
[15]	Czech	0.5
[15]	SE France	0.4
[18]	Kampala (Uganda)	0.3
[15]	N. Greece	0.3
[15]	Romania	0.3
[15]	Sudanese	0.25
[15]	U. Arab Emerates	0.25
[15]	Japan	0.0
[15]	Croatia	0.0
[15]	N. Ireland	0.0
[15]	Zambia	0.0
[15]	Luo (Kenya)	0.0
[15]	Nandi (Kenya)	0.0
[15]	Bandiagara (Mali)	0.0

Distribution of A69 places nodal center in the Levant, but high levels in West Africa. The model of human genetic origin places first migrations from Eastern Africa. However in many east African populations the frequency of A69 is zero. A more consistent model of A69 distribution is either a subsequent migration from West Africa, supported by A36 and HLA DR3-DQ2. The higher levels in the Gaza Palestinians supports this hypothesis.

Disease associations

A69 may be associated with sarcoidosis.^[19]

References

1. Arce-Gomez B, Jones EA, Barnstable CJ, Solomon E, Bodmer WF (February 1978). "The genetic control of HLA-A and B antigens in somatic cell hybrids: requirement for beta2 microglobulin". Tissue Antigens 11 (2): 96–112. doi:10.1111/j.1399-0039.1978.tb01233.x. PMID 77067.
2. Holmes N, Parham P (1985). "Exon shuffling in vivo can generate novel HLA class I molecules". EMBO J. 4 (11): 2849–54. PMC 554588. PMID 3877632.
3. Allele Query Form IMGT/HLA - European Bioinformatics Institute
4. Arnaiz-Villena A, Elaiwa N, Silvera C, et al. (2001). "The origin of Palestinians and their genetic relatedness with other Mediterranean populations". Hum. Immunol. 62 (9): 889–900. doi:10.1016/S0198-8859(01)00288-9. PMID 11543891. (Retracted. If this is intentional, please replace {{Retracted}} with {{Retracted|intentional=yes}}.)
5. Spínola H, Bruges-Armas J, Middleton D, Brehm A (2005). "HLA polymorphisms in Cabo Verde and Guiné-Bissau inferred from sequence-based typing". Hum. Immunol. 66 (10): 1082–92. doi:10.1016/j.humimm.2005.09.001. PMID 16386651.
6. Proceedings of IHW Workshop, Seattle 2002, via http://www.allelefrequencies.net via Middleton D, Menchaca L, Rood H, Komerofsky R (2003). "New allele frequency database: http://www.allelefrequencies.net". Tissue Antigens 61 (5): 403–7. doi:10.1034/j.1399-0039.2003.00062.x. PMID 12753660. External link in |title= (help)
7. Modiano D, Luoni G, Petrarca V, et al. (2001). "HLA class I in three West African ethnic groups: genetic distances from sub-Saharan and Caucasoid populations". Tissue Antigens 57 (2): 128–37. doi:10.1034/j.1399-0039.2001.057002128.x. PMID 11260507.
8. Ivanova M, Rozemuller E, Tyufekchiev N, Michailova A, Tilanus M, Naumova E (2002). "HLA polymorphism in Bulgarians defined by high-resolution typing methods in comparison with other populations". Tissue Antigens 60 (6): 496–504. doi:10.1034/j.1399-0039.2002.600605.x. PMID 12542743.
9. Maccabi Healthcare Services Histocompatibility Dept. Israel, bone marrow registry, via http://www.allelefrequencies.net
10. Hajjej A, Kâabi H, Sellami MH, et al. (2006). "The contribution of HLA class I and II alleles and haplotypes to the investigation of the evolutionary history of Tunisians". Tissue Antigens 68 (2): 153–62. doi:10.1111/j.1399-0039.2006.00622.x. PMID 16866885.
11. DW, Gjertson; PI, Terasaki (1998). HLA 1998: proceedings of the twelfth International Histocompatibility Workshop and Conference. ASHI. via http://www.allelefrequencies.net
12. Rani R, Marcos C, Lazaro AM, Zhang Y, Stastny P (2007). "Molecular diversity of HLA-A, -B and -C alleles in a North Indian population as determined by PCR-SSOP". Int. J. Immunogenet. 34 (3): 201–8. doi:10.1111/j.1744-313X.2007.00677.x. PMID 17504510.
13. Sánchez-Velasco P, Karadsheh NS, García-Martín A, Ruíz de Alegría C, Leyva-Cobián F (2001). "Molecular analysis of HLA allelic frequencies and haplotypes in Jordanians and comparison with other related populations". Hum. Immunol. 62 (9): 901–9. doi:10.1016/S0198-8859(01)00289-0. PMID 11543892.
14. Grimaldi MC, Crouau-Roy B, Amoros JP, et al. (2001). "West Mediterranean islands (Corsica, Balearic islands, Sardinia) and the Basque population: contribution of HLA class I molecular markers to their evolutionary history". Tissue Antigens 58 (5): 281–92. doi:10.1034/j.1399-0039.2001.580501.x. PMID 11844138.
15. Middleton D, Menchaca L, Rood H, Komerofsky R (2003). "New allele frequency database: http://www.allelefrequencies.net". Tissue Antigens 61 (5): 403–7. doi:10.1034/j.1399-0039.2003.00062.x. PMID 12753660. External link in |title= (help)
16. Comas D, Mateu E, Calafell F, et al. (1998). "HLA class I and class II DNA typing and the origin of Basques". Tissue Antigens 51 (1): 30–40. doi:10.1111/j.1399-0039.1998.tb02944.x. PMID 9459501.
17. Farjadian S, Naruse T, Kawata H, Ghaderi A, Bahram S, Inoko H (2004). "Molecular analysis of HLA allele frequencies and haplotypes in Baloch of Iran compared with related populations of Pakistan". Tissue Antigens 64 (5): 581–7. doi:10.1111/j.1399-0039.2004.00302.x. PMID 15496201.
18. Cao K, Moormann AM, Lyke KE, et al. (2004). "Differentiation between African populations is evidenced by the diversity of alleles and haplotypes of HLA class I loci". Tissue Antigens 63 (4): 293–325. doi:10.1111/j.0001-2815.2004.00192.x. PMID 15009803.
19. Bilir M, Sipahi S, Yilmaz E, et al. (2007). "Analysis of HLA antigens in Turkish sarcoidosis patients". South. Med. J. 100 (4): 356–9. doi:10.1097/SMJ.0b013e31802f3763. PMID 17458393.