HLA-A2

HLA-A2 (MHC Class I, A cell surface antigen)

^{Rendering of 2git: α (A*0201 gene product), β₂-microglobulin, and HIV peptide.}
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Protein	transmembrane receptor/ligand
Structure	αβ heterodimer
Subunits	HLA-A*02--, β₂-microglobulin
Older names	"HL-A2"
^-
subtype	allele	Available structures
A2.1	*0201	3hla, 2gj6, 2git, 2clr, 2bsv, 2c7u, 2bsu, 2av1, 2av7, 1tvb, 1tvh, 1s8d, 1s9w, 1s9x, 1s9y, 1t1w, 1t1x, 1t1y, 1t1z, 1t20, 1t21, 1t22, 1qse, 1qr1, 1qrn, 1p7q, 1jf1, 1jht, 1i1f, 1i1y, 1i4f, 1i7r, 1i7t, 1i7u, 1im3, 1akj, 1ao7, 1b0g, 1b0r, 1bd2, 1duy, 1duz, 1eey, 1eez, 1hhg, 1hhh, 1hhi, 1hhj, 1hhk, 1hla
A2.2F	*0202
A2.3, A203	*0203
A2.2Y	*0205
A2.4a	*0206
^{rare alleles}
A2.4	*0204
A2.4b	*0207
A2.5	*0211
Alleles link-out to IMGT/HLA database at EBI

HLA-A2 (A2) is a human leukocyte antigen serotype within HLA-A "A" serotype group. The serotype is determined by the antibody recognition of α² subset of HLA-A α-chains. For A2, the alpha "A" chain are encoded by the HLA-A*02 allele group and the β-chain are encoded by B2M locus.^[1] A2 and A*02 are almost synonymous in meaning. A2 is more common in Northern Asia and North America than elsewhere, and it is part of a several long haplotypes.

Further information: HLA serotypes explained

The serotype identifies the gene products of many HLA-A*02 alleles, including HLA-A*0201, *0202, *0203, *0206, and *0207 gene products. A*02 is globally common, but A*0201 is at high frequencies in Northern Asia and North America. A2 is the most diverse serotype, showing diversity in Eastern Africa and Southwest Asia. While the frequency of A*0201 in Northern Asia is high, its diversity is limited to A*0201 the less common Asian variants A*0203, A*0206.

1 Serotype
- 1.1 Disease Associations
  - 1.1.1 By haplotype
2 Alleles
3 A2-B Haplotypes
- 3.1 A2-Cw5-B44
4 References

Serotype

A2 recognition of some HLA A*02 gene products^[2]
A*02	A2	Sample
allele	%	size (N)
*0201	98	6315
*0202	81	859
*0203	64	472
*0205	81	462
*0206	68	636
*0207	80	135
*0211	74	228

The serotyping for the most abundant A*02 alleles is good. For A*0203, A*0206, A*0207 serotyping is borderline useful. There is a separate serotyping for A203 and A210. There are over 125 alleles identified (mostly by sequence homology) as being A2, of those 8 are nulls, and a large majority have unknown serotypes.

Disease Associations

A2 Associated with spontaneous abortion in A2+/A[other] phenotypic children^[3]

By haplotype

A*02:Cw*16 is associated with increased higher viral load in HIV^[4]

Alleles

**HLA A*0201 frequencies**
Study population	Freq. (in %)^[5]
Mexico Sonora Seri	54.5
USA Arizona Pima	43.6
USA New Mexico Canoncito …	37.8
Finland	34.4
Mexico Mestizos	34.1
Georgia Tibilisi Georgian…	31.0
Bulgaria	30.0
Philippines Ivatan	30.0
Spain Catalonia Girona	29.9
USA South Dakota Lakota S…	29.7
Portugal North	29.3
Italy North pop 1	28.9
Mexico Zaptotec Oaxaca	28.4
Italy Bergamo	28.0
Czech Republic	27.4
Ireland Northern	27.4
USA Caucasian (2)	27.2
Spain Basque Gipuzkoa Pro…	27.0
Belgium	26.6
Croatia	26.3
Australia New South Wales	26.1
Portugal Centre	26.0
Turkey (1)	25.7
Mexico Chihuahua State Ta…	25.0
Romanian	25.0
Ireland South	24.6
Mexico Guadalajara Mestiz…	22.3
China Tibet	21.8
USA North American Native…	21.7
USA South Texas Hispanics	21.7
Oman	21.6
Venezuela Perja Mountain …	21.6
Georgia Svaneti Svans	21.3
Brazil Terena	20.8
Iran Baloch	20.2
Japan Ainu Hokkaido	20.0
Brazil	19.2
China Beijing	18.7
Uganda Kampala	18.4
Morocco Nador Berber	17.8
Australia Indig. Cape Yor…	17.5
Tunisia	17.5
Sudanese	17.3
South Korea (3)	16.5
Mongolia Buriat	14.3
Burkina Faso Rimaibe	13.8
Jordan Amman	13.4
Zambia Lusaka	12.8
USA African Americans (3)	12.1
Japan (3)	11.6
India Tamil Nadu Nadar	10.7
Japan Okinawa Ryukuan	10.2
Zimbabwe Harare Shona	9.1
Ecuador Cayapa	9.0
Kenya	8.7
Georgia Tibilisi Kurds	8.3
Mali Bandiagara	8.3
Senegal Niokholo Mandenka	8.1
Cameroon Yaounde	7.1
Singapore Riau Malay	6.5
India North Hindus	5.8
Taiwan Hakka	5.5
Taiwan Pazeh	5.5
China South Han	5.3
Burkina Faso Fulani	5.1
Sri Lanka Colombo Sinhale…	4.9
China Guangxi Maonan	4.6
Singapore Javanese Indone…	4.0
Taiwan Paiwan	3.9
India Andhra Pradesh Goll…	3.4
Singapore Thai	3.1
Taiwan Rukai	3.0
Taiwan Tsou	2.9
Pakistan Karachi Parsi	2.8
Taiwan Ami	2.6
South Africian Natal Zulu	2.5
New Caledonia	2.4
USA Alaska Yupik Natives	2.4
PNG Wanigela	2.1
Taiwan Puyuma	2.0
Taiwan Tao	2.0
India Mumbai Marathas	1.9
Thailand	1.8
South Africa Natal Tamil	1.0
Allele frequencies presented, only

**HLA A*0202 frequencies**
Study population	Freq. (in %)^[5]
Cameroon Bamileke	10.4
Senegal Niokholo Mandenka	9.1
Cameroon Yaounde	8.2
Mali Bandiagara	7.6
Guinea Bissau	6.2
Cameroon Beti	6.0
Burkina Faso Rimaibe	5.3
Kenya	4.9
Georgia Svaneti Svans	3.8
USA African Americans (2)	3.7
Zimbabwe Harare Shona	3.6
South Africian Natal Zulu	3.5
Uganda Kampala	3.4
Saudi Arabia Guraiat and …	2.4
Pakistan Brahui	2.3
Zambia Lusaka	2.3
Israel Arab Druse	2.0
Sudanese	1.8
India North Delhi	1.7
Pakistan Karachi Parsi	1.7
China Qinghai Hui	1.4
Portugal North	1.1
Georgia Tibilisi Georgian…	1.0
Tunisia	1.0
Allele frequencies presented, only

**HLA A*0203 frequencies**
Study population	Freq. (in %)^[5]
China Guangxi Maonan	17.6
China Yunnan Lisu	15.2
Thailand Northeast	12.2
China South Han	10.8
China Guangzhou	9.8
Singapore Javanese Indone…	9.0
China Yunnan Nu	8.2
Thailand	7.7
Taiwan Minnan pop 1	6.4
Taiwan Puyuma	6.0
Taiwan Siraya	5.9
Singapore Riau Malay	5.2
India Khandesh Pawra	5.0
India West Bhils	5.0
Taiwan Pazeh	4.5
USA Asian	4.2
India Mumbai Marathas	3.7
Taiwan Hakka	3.6
China North Han	2.4
Sri Lanka Colombo Sinhale…	2.4
China Qinghai Hui	2.3
Burkina Faso Rimaibe	1.1
Taiwan Saisiat	1.0
Allele frequencies presented, only

**HLA A*0205 frequencies**
Study population	Freq. (in %)^[5]
Burkina Faso Fulani	9.2
Kenya Nandi	8.7
Sudanese	6.5
Saudi Arabia Guraiat and …	6.1
Italy North (1)	5.8
South Africian Natal Zulu	5.5
Cameroon Pygmy Baka	5.0
Georgia Tibilisi Kurds	5.0
Burkina Faso Rimaibe	4.3
Israel Arab Druse	4.0
Cameroon Sawa	3.8
Turkey (1)	3.5
Mongolia Buriat	3.2
Zimbabwe Harare Shona	3.1
India New Delhi	3.0
USA African America	3.0
Bulgaria	2.7
Cameroon Bamileke	2.6
Kenya Luo	2.6
Pakistan Sindhi	2.5
Tunisia	2.5
Cuban Mulatto	2.4
Czech Republic	2.4
Spain Catalonia Girona	2.3
Cameroon Yaounde	2.2
Mali Bandiagara	2.2
Uganda Kampala	2.2
Italy Bergamo	2.1
Oman	2.1
USA African Americans (2)	1.7
China North Han	1.4
Georgia Tibilisi Georgian…	1.4
Kenya	1.4
Ireland Northern	1.2
Cameroon Beti	1.1
India North Delhi	1.1
Senegal Niokholo Mandenka	1.1
USA Caucasians (3)	1.1
India North Hindus	1.0
Mexico Mixtec Oaxaca	1.0
Portugal Centre	1.0
Spain Basque Gipuzkoa Pro…	1.0
Allele frequencies presented, only

**HLA A*0206 frequencies**
Study population	Freq. (in %)^[5]
Mexico Mixe Oaxaca	34.9
Mexico Zaptotec Oaxaca	26.1
Mexico Mixtec Oaxaca	21.6
Pakistan Kalash	21.6
Japan Ainu Hokkaido	20.0
Japan Okinawa Ryukuan	18.3
USA Alaska Yupik Natives	16.5
USA Hawaii Okinawa	14.3
American Samoa	13.0
Mexico Chihuahua State Ta…	12.5
Taiwan Puyuma	12.0
USA South Dakota Lakota S…	10.5
Taiwan Atayal	9.4
Japan pop3	8.7
Japan pop5	8.4
India North Delhi	7.7
Japan Central	7.7
USA Arizona Pima	7.6
Taiwan Bunun	7.4
USA South Texas Hispanics	7.3
USA North American Native…	7.2
China North Han	7.1
South Korea pop 3	7.1
Russia Tuva pop 2	6.9
Mexico Mestizos	6.1
Pakistan Burusho	6.0
Taiwan Taroko	5.5
Singapore Chinese Han	5.2
USA Asian	5.0
USA New Mexico Canoncito …	4.9
China Beijing	4.8
China Beijing Shijiazhuan…	4.7
Hong Kong Chinese	4.7
China Guangxi Maonan	4.6
Mongolia Buriat	4.3
China Guangzhou	4.0
Philippines Ivatan	4.0
Singapore Chinese	4.0
Taiwan Pazeh	3.6
China South Han	3.5
Taiwan Thao	3.3
Pakistan Sindhi	3.2
USA Hispanic	3.2
Pakistan Pathan	3.1
India New Delhi	3.0
Taiwan Rukai	3.0
India North Hindus	2.9
Taiwan Minnan pop 1	2.9
Taiwan Paiwan	2.9
India Andhra Pradesh Goll…	2.8
Taiwan Hakka	2.7
Papua New Guinea Eastern …	2.6
Thailand	2.5
Sri Lanka Colombo Sinhale…	2.4
Pakistan Brahui	2.3
Papua New Guinea Wanigela	2.1
Singapore Javanese Indone…	2.0
Singapore Riau Malay	2.0
Singapore Thai	2.0
Taiwan Saisiat	2.0
Taiwan Siraya	2.0
Pakistan Baloch	1.6
Taiwan Ami	1.5
Zambia Lusaka	1.2
Iran Baloch	1.1
Pakistan Karachi Parsi	1.1
Allele frequencies presented, only

**HLA A*0207 frequencies**
Study population	Freq. (in %)^[5]
Thailand Northeast	15.7
China Guangxi Maonan	13.4
Hong Kong Chinese	13.1
Singapore Chinese	13.1
Singapore Thai	12.2
Singapore Chinese Han	11.6
Taiwan Minnan pop 1	11.3
Thailand	10.9
China South Han	9.4
China Guangzhou	9.3
China Yunnan Nu	8.2
Taiwan Hakka	8.2
Taiwan Siraya	6.9
China Beijing	6.7
USA Asian	6.6
Taiwan Pazeh	6.4
China North Han	4.3
China Qinghai Hui	3.6
Japan (3)	3.4
South Korea (3)	3.0
China Inner Mongolia	2.5
China Yunnan Lisu	2.2
Mongolia Buriat	2.1
Singapore Riau Malay	2.0
Taiwan Thao	1.7
China Tibet Autonomous Re…	1.6
Russia Tuva pop 2	1.6
USA Hawaii Okinawa	1.4
Burkina Faso Fulani	1.0
Japan Ainu Hokkaido	1.0
Singapore Javanese Indone…	1.0
Allele frequencies presented, only

**HLA A*0211 frequencies**
Study population	Freq. (in %)^[5]
India Khandesh Pawra	16.0
South Africa Natal Tamil	13.0
India Andhra Pradesh Goll…	9.7
India Mumbai Marathas	8.6
Sri Lanka Colombo Sinhale…	7.4
India North Hindus	6.7
Ecuador Cayapa	4.8
India West Bhils	4.0
Pakistan Sindhi	2.5
Pakistan Brahui	2.3
Pakistan Pathan	2.0
Singapore Javanese Indone…	2.0
India North Delhi	1.7
Pakistan Baloch	1.6
Singapore Riau Malay	1.2
Iran Baloch	1.1
Pakistan Burusho	1.1
Allele frequencies presented, only

A2-B Haplotypes

A2-B7 (Node in Netherlands) A2-B5

A2-B51
A2-B52

A2-B8
A2-B13
A2-B14

A2-B64
A2-B65

A2-B15

A2-B62
A2-B63
A2-B70,71,75,76
A2-B46 (Node in Southern China, may be most abundant haplotype)

A2-B16

A2-B44
A2-B45

A2-B18
A2-B27
A2-B35
A2-B37 A2-B39 (Node in North American Amerinds)
A2-B40

A2-B60
A2-B61

A2-B46

A2-Cw5-B44

HLA A2-B44 haplotype frequencies
		freq		Rank in
ref.	Population	(%)		Pop.
^[6]	Cornish	11.4	¹	1
^[7]	Ireland	9.2		2
^[8]	Northern Ireland	8.0	¹	2
^[6]	Sweden	7.2		2
^[9]	Swiss	6.9		2
^[6]	Polish	6.2		1
^[6]	Spanish	5.9		1
^[6]	Ukraine	5.9		1
^[10]	Dutch Netherlands	5.9		3
^[6]	Dane	4.8		1
^[6]	Czech	4.7		3
^[6]	Basque	4.7		3
^[6]	Greek	4.5		3
^[6]	Yugoslavian	4.4
^[6]	Hungarian	3.5
^[6]	British	2.6		4
[1]	Romania	2.5
^[6]	Austria	2.4
¹Cw*0501 (Eur.)

A2-Cw5-B44 is the multi-serotype designation for the haplotype HLA-A*0201:C*0501:B*4402, the class I portion, of an ancetral haplotype (A2-B44-DR4-DQ8). The full haplotype is (for relative distances see Human leukocyte antigens:

A*0201 : C*0501 : B*4402 : DRB1*0401 : DQA1*0301 : DQB1*0302

Another haplotype that is more common in Central Europe is the (A2-B44-DR7-DQ2)

A*0201 : C*0501 : B*4402 : DRB1*0701 : DQA1*0201 : DQB1*0202

Over northwestern Europe A2-B44 shows a single common ancestor which contributed the Cw5 allele to the haplotype. The haplotype appears to have been introduced early in European prehistoric period, frequencies of the haplotype generally correlate with A1-Cw7-B8 and A2-B7. The haplotype is considerably more equilibrated relative to A1-B8 and a possible reason is gene flow from iberia or the east with related haplotypes after initial migrations.

References

^ 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.
^ Allele Query Form IMGT/HLA - European Bioinformatics Institute
^ Komlos L, Klein T, Korostishevsky M (2007). "HLA-A2 class I antigens in couples with recurrent spontaneous abortions". Int. J. Immunogenet. 34 (4): 241–6. doi:10.1111/j.1744-313X.2007.00682.x. PMID 17627758.
^ Tang J, Tang S, Lobashevsky E, Myracle A, Fideli U, Aldrovandi G, Allen S, Musonda R, Kaslow R (2002). "Favorable and unfavorable HLA class I alleles and haplotypes in Zambians predominantly infected with clade C human immunodeficiency virus type 1.". J Virol 76 (16): 8276–84. doi:10.1128/JVI.76.16.8276-8284.2002. PMC 155130. PMID 12134033. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=155130.
^ ^a ^b ^c ^d ^e ^f ^g 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.
^ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k ^l ^m Sasazuki, Takehiko; Tsuji, Kimiyoshi; Aizawa, Miki (1992). HLA 1991: proceedings of the eleventh International Histocompatibility Workshop and Conference, held in Yokohama, Japan, 6-13 November, 1991. Oxford [Oxfordshire]: Oxford University Press. ISBN 0-19-262390-7.
^ Finch T, Lawlor E, Borton M, Barnes C, McNamara S, O'Riordan J, McCann S, Darke C (1997). "Distribution of HLA-A, B and DR genes and haplotypes in the Irish population.". Exp Clin Immunogenet 14 (4): 250–63. PMID 9523161.
^ Middleton D, Williams F, Hamill M, Meenagh A (2000). "Frequency of HLA-B alleles in a Caucasoid population determined by a two-stage PCR-SSOP typing strategy.". Hum Immunol 61 (12): 1285–97. doi:10.1016/S0198-8859(00)00186-5. PMID 11163085.
^ Grundschober C, Sanchez-Mazas A, Excoffier L, Langaney A, Jeannet M, Tiercy J (1994). "HLA-DPB1 DNA polymorphism in the Swiss population: linkage disequilibrium with other HLA loci and population genetic affinities.". Eur J Immunogenet 21 (3): 143–57. doi:10.1111/j.1744-313X.1994.tb00186.x. PMID 9098428.
^ Schipper R, Schreuder G, D'Amaro J, Oudshoorn M (1996). "HLA gene and haplotype frequencies in Dutch blood donors.". Tissue Antigens 48 (5): 562–74. doi:10.1111/j.1399-0039.1996.tb02670.x. PMID 8988539.

HLA-A serotypes

HLA-A · A1 · A2 · A3 · A9 (A23 · A24) · A10 (A25 · A26 · A34 · A43 · A66) · A11 · A19 (A29 · A30 · A31 · A32 · A33 · A74) · A28 (A68 · A69) · A36 · A80