By allele

A*68 is associated with higher viral load in HIV

HIV

Human immunodeficiency virus is a lentivirus that causes acquired immunodeficiency syndrome , a condition in humans in which progressive failure of the immune system allows life-threatening opportunistic infections and cancers to thrive...

. A68 may be protective
against symptomatic heart disease in Chaga's cardiomyopathy.

Allele freqeuncies

A68 can be subdivided into 3 alleles, *6801, *6802, *6803. *6801 can also be subdivided into *680101 and *680102 (previously called *68011 and *68012).

A*6801

A*6801 is higher in certain Native American

Indigenous peoples of the Americas

The indigenous peoples of the Americas are the pre-Columbian inhabitants of North and South America, their descendants and other ethnic groups who are identified with those peoples. Indigenous peoples are known in Canada as Aboriginal peoples, and in the United States as Native Americans...

 groups, South Asia

South Asia

South Asia, also known as Southern Asia, is the southern region of the Asian continent, which comprises the sub-Himalayan countries and, for some authorities , also includes the adjoining countries to the west and the east...

n peoples, African peoples, however *6801 is at low levels in most of SE Asia, particularly the indigeonous populations. This is also reflected by low levels along the West Pacific Rim including Japan. The hiatus of *6801 breaks in Northern Japan with the 3% frequency found in the Ainu

Ainu people

The , also called Aynu, Aino , and in historical texts Ezo , are indigenous people or groups in Japan and Russia. Historically they spoke the Ainu language and related varieties and lived in Hokkaidō, the Kuril Islands, and much of Sakhalin...

, which continues to increase with Arctic peoples and falls of in Native Americans. Whereas in the Western Eurasia

Eurasia

Eurasia is a continent or supercontinent comprising the traditional continents of Europe and Asia ; covering about 52,990,000 km2 or about 10.6% of the Earth's surface located primarily in the eastern and northern hemispheres...

's northern regions, A*6801 falls off. In both Africa and the New World both A*680101 and A*680102 can be found. Although in the New World A*680102 is more prevalent.

HLA A*6802 frequencies

		freq
ref.	Population	(%)
	Yucpa (Venezuela)	37.2
	Nandi (Kenya)	11.6
	Kenya	10.5
	Harare Shona (Zimbabwe)	9.8
	Natal Zulu (S. Africia)	9.5
	Luo (Kenya)	7.6
	Mali Bandiagara	6.2
	Sudanese	5.5
	Kampala (Uganda)	5.2
	Baka Pygmy (Cameroon)	5.0
	Mestizos (Guadalajara,Mexico)	4.9
	SEastern Isl (Cape Verde)	4.8
	Nador Metalsa (Morocco)	4.8
	Chiriguanos (Argentina)	4.7
	Mossi (Burkina Faso)	4.7
	Lusaka (Zambia)	4.7
	Bamileke (Cameroon)	4.5
	Sawa (Cameroon)	3.8
	Kalash (Pakistan)	3.3
	Beti (Cameroon)	3.2
	SE France	3.1
	Seri (Sonora,Mexico)	3.0
	Yaounde (Cameroon)	2.8
	Tunisia	2.5
	Guinea Bissau	2.3
	Fulani (Burkina Faso)	2.0
	S. Portugal	2.0
	Oman (E. Arabia)	1.7
	Corsica (France)	1.6
	Baloch (Pakistan)	1.6
	Niokholo Mandenka (Senegal)	1.6
	Eastern Andalusia (Spain)	1.5
	Orkney (Scotland)	1.4
	Mestizos (Mexico)	1.2
	Baloch(Iran)	1.1
	Bergamo (Italy)	1.1
	Northern Han (China)	1.0
	Central Portugal	1.0
	Czech Republic	0.9
	Northern Ireland	0.9
	Jews (Israel)	0.9
	Mixe (Oaxaca,Mexico)	0.9
	Madeira (Spain)	0.8
	Cayapa (Ecuador)	0.6
	Svans (Georgia)	0.6
	Majorca/Minorca (Spain)	0.6
	Belgium	0.5
	Lakota (Sioux)	0.5

A*6802

A*6802 has a global node within certain native peoples of South America, at 37%. A secondary node can be found in Africa. Like *6801 there is an hiatus of *6802 in SE Asia's indigeonous populations, indicating that this population is not a likely source within the native peoples of the New World. Levels are generally low (<1%) in Europe except along the Mediterranean coast. In Africa, higher levels can be found in Kenya and in Western Africa and the Cape Verde Islands. A note on purity, the notion that A*6802 is of indigeonous native American origin can be challenged based on possibility of introgression from Europeans and Africans. In the case of the Yucpa this is not tenable. The Yucpa have an HLA-DQ8 frequency of ~80%, the highest DQ allele frequency in the world, this tribe shows little evidence of European genetic introgression, in addition the closest DQ8 frequency in terms of Africa are the isolated !Kung

!Kung people

The ǃKung, also spelled ǃXun, are a Bushman people living in the Kalahari Desert in Namibia, Botswana and in Angola. They speak the ǃKung language, noted for using click consonants, generally classified as part of the Khoisan language family...

 of Namibia

Namibia

Namibia, officially the Republic of Namibia , is a country in southern Africa whose western border is the Atlantic Ocean. It shares land borders with Angola and Zambia to the north, Botswana to the east and South Africa to the south and east. It gained independence from South Africa on 21 March...

. There are two possible sources of A*6802: Africa direct and Africa via Asia. The associated B alleles (B*48, B*61) point toward and Asian origin or an African source of very ancient origin, since time would be required to recombine Asian typical B alleles with A68. In the Spanish, A28 levels are 3.1% of this ~0.5% is A*6901, A*6802 is about 2.0% which means the net level of A*6802 to A*6805 in the Spanish is ~0.5%. Of 11 NA groups surveyed 9 are above and 2 are below 0.5%. Of the two Spanish groups 1 (Andalusia - 1.5%) is above and the other (Catalon 0.0%) is below. In an admixture model
Spanish introgression does not explain A*6802 in the New World. The Asian model of migration shows no single people NE of Pakistan that has A*6802.

A*6803

HLA A*6803 frequencies

		freq
ref.	Population	(%)
	Mayan (Guatemala)	7.6
	Bakalo pygmy (Cameroon)	6.0
	Mestizo (Guadalajara, Mexico)	3.9
	Mestizo (Mexico)	3.7
	Mbenzele Pygmy (Central African)	1.5
	Lakota (Souix)	1.2
	Yupik (Eskimo-Alaska)	1.0
	Buriat (Mongolia)	0.4
	N. Ireland, Romania, Czech,	0.0

A*6803 can be found in native peoples of the New World and in Central Asia, in Africa it appears to be limited to West and Central Africans. This distribution along with the information on 6801 and 6802 suggests a probable redistribution of *68 alleles from Africa after the initial migration from East Africa

East Africa

East Africa or Eastern Africa is the easterly region of the African continent, variably defined by geography or geopolitics. In the UN scheme of geographic regions, 19 territories constitute Eastern Africa:...

that colonized Southeast Asia. It also provides support for 2 waves of migration from Asia to the New World or, at minimum, an unknown mixing area of West Pacific Rim haplotypes and West African/Middle Eastern derived haplotypes in Eastern Asia before the first migration. At present the incursion of Western Eurasian peoples into East Asia follows evidence for reuse of transbiakal region after 18,300 years and correlates with the insipient Jomon period of Japan several thousands of years later. Certain alleles and haplotypes of HLA in South Americans target Japans estimated pre-Yayoi composition, but other peoples, for example in western Mexico are most similar to the Ainu and the peoples of the Amur basin.

A68 haplotypes

The genetic distance between Native Americans and Eurasians is too great for the persistence of shared haplotypes, particularly in light of the lower levels in most of Siberia. The link of haplotypes with Western Africa may be significant, and may indicate a rapid eastward migration and admixing within the late paleolithic period.

Indigeonous American haplotypes

A*680102-B35 haplotypes

• A*680102 Cw*0304 B*3506 (A68-Cw10-B35)
• A68-Cw4-B35 (Terena, Seri (Mexico))
  • A*680102 Cw*0401 B83521 (A68-Cw4-B35) (Terena)

A*6802-B35

• A*6802-B3501 Guadalahara.
• A*6802-B3502 Guadalahara.

A68-B35 Mayan (A*6803).

These two haplotypes are consistent with the presence of Cw4-B35 and A68 in Asia and Middle East and A68-B35 maybe the ancestral A68 haplotype. A28(A*6802)-B35 is found in Senegal.
A6801-B4002/4 - Terena, Eskimo, Mestizo, Tribal Indians (Asia)

A*680102-B*520102 in the Mexican Mestizo population. A28(A*6802)-B52 is also found in Senegal.

Old World A68 haplotypes

A28(~A68)-B51 Armenia, Senegal, Eskimo

A28(~A68)-B70 W. Afr, Zaire, Zimbabwe, N. and S. African (Non-caucasians), Khoi (Hottentot)