HLA-B46
Encyclopedia
Alleles B*4601
Structure (See HLA-B
HLA-B
HLA-B is a human gene that provides instructions for making a protein that plays a critical role in the immune system. HLA-B is part of a family of genes called the human leukocyte antigen complex...

)
Symbol(s)
Human Genome Organisation
The Human Genome Organisation is an organization involved in the Human Genome Project, a project about mapping the human genome. HUGO was established in 1989 as an international organization, primarily to foster collaboration between genome scientists around the world...

HLA-B
EBI-HLA
European Bioinformatics Institute
The European Bioinformatics Institute is a centre for research and services in bioinformatics, and is part of European Molecular Biology Laboratory...

B*4601
Locus
Locus (genetics)
In the fields of genetics and genetic computation, a locus is the specific location of a gene or DNA sequence on a chromosome. A variant of the DNA sequence at a given locus is called an allele. The ordered list of loci known for a particular genome is called a genetic map...

chr.6
Chromosome 6 (human)
Chromosome 6 is one of the 23 pairs of chromosomes in humans. People normally have two copies of this chromosome. Chromosome 6 spans more than 170 million base pairs and represents between 5.5 and 6% of the total DNA in cells...

 6p21.31


HLA-B46 (B46) is an HLA
Human leukocyte antigen
The human leukocyte antigen system is the name of the major histocompatibility complex in humans. The super locus contains a large number of genes related to immune system function in humans. This group of genes resides on chromosome 6, and encodes cell-surface antigen-presenting proteins and...

-B
HLA-B
HLA-B is a human gene that provides instructions for making a protein that plays a critical role in the immune system. HLA-B is part of a family of genes called the human leukocyte antigen complex...

 serotype
Serotype
Serotype or serovar refers to distinct variations within a subspecies of bacteria or viruses. These microorganisms, viruses, or cells are classified together based on their cell surface antigens...

. The serotype identifies the gene product
Gene product
A gene product is the biochemical material, either RNA or protein, resulting from expression of a gene. A measurement of the amount of gene product is sometimes used to infer how active a gene is. Abnormal amounts of gene product can be correlated with disease-causing alleles, such as the...

s of HLA-B*4601 allele.
B*4601 resulted from a rare, interlocus, gene conversion
Gene conversion
Gene conversion is an event in DNA genetic recombination, which occurs at high frequencies during meiotic division but which also occurs in somatic cells. It is a process by which DNA sequence information is transferred from one DNA helix to another DNA helix, whose sequence is altered.It is one...

 between B62
HLA-B62
HLA-B62 is an HLA-B serotype. The serotype identifies certain B*15 gene-allele protein products of HLA-B.B62 is largest of many split antigens of the broad antigen, B15. B62 best identifies the B*1501, B*1504, B*1507, and B*1525 allele products....

, probably B*1501, and a HLA-C
HLA-C
HLA-C belongs to the MHC class I heavy chain receptors. The C receptor is a heterodimer consisting of a HLA-C mature gene product and β2-microglobulin. The mature C chain is anchored in the membrane...

 allele. B*4601 is the most common HLA-B allele that does not have an origin within Africa, and estimated 400 million people in Eastern Asia carry a B46 allele. When found B*4601 segregates with only 2 HLA-C
HLA-C
HLA-C belongs to the MHC class I heavy chain receptors. The C receptor is a heterodimer consisting of a HLA-C mature gene product and β2-microglobulin. The mature C chain is anchored in the membrane...

w alleles, A limited number of HLA-A
HLA-A
HLA-A are a group of human leukocyte antigens that are encoded by the HLA-A locus on human chromosome 6p. The HLA genes constitute a large subset of the Major histocompatibility complex of humans. HLA-A is a component of certain MHC class I cell surface receptor isoforms that resides on the...

 and HLA-DRB1
HLA-DRB1
HLA class II histocompatibility antigen, DRB1-9 beta chain is a protein that in humans is encoded by the HLA-DRB1 gene. DRB1 encodes the most prevalent beta subunit of HLA-DR.- Function :...

 alleles suggesting that the allele recently expanded from a limited sized group within SE Asia. Extremely low frequencies outside of Eastern Asia are indicators of a recent expansion of B46 from a recently small population. The frequency distribution suggests the ancestral B46 population was in SE China, or, potentially Burma (Myanmar or Laos, untested). B46 in Asia correlates with wet-rice farming
Paddy field
A paddy field is a flooded parcel of arable land used for growing rice and other semiaquatic crops. Paddy fields are a typical feature of rice farming in east, south and southeast Asia. Paddies can be built into steep hillsides as terraces and adjacent to depressed or steeply sloped features such...

. The exceptions are notable, it has been found in the Nivkhi on north-eastern Sakalin Island, the Ainu, and the Nivkhi-related (genetically) Tlinglet population of Alaska at trace levels.

Serotype

B46 serotype recognition of Some HLA B*46 allele-group gene products
B*46 B46 Other Sample
allele % % size (N)
4601 59 29 1487


The serotyping is poor for B*4601 and it is preferable to use SSP-PCR.



B*4601 Allele Frequencies

HLA B*4601 frequencies
freq
ref. Population (%)
Buyei
Buyei
The Buyei are an ethnic group living in southern mainland China. Numbering 2.5 million, they are the 11th largest of the 56 ethnic groups officially recognized by the People's Republic of China...

 (China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...

)
21.6
Miao
Miao people
The Miao or ม้ง ; ) is an ethnic group recognized by the government of the People's Republic of China as one of the 55 official minority groups. Miao is a Chinese term and does not reflect the self-designations of the component nations of people, which include Hmong, Hmu, A Hmao, and Kho Xiong...

 (China)
18.4
Han (2) (Yunnan
Yunnan
Yunnan is a province of the People's Republic of China, located in the far southwest of the country spanning approximately and with a population of 45.7 million . The capital of the province is Kunming. The province borders Burma, Laos, and Vietnam.Yunnan is situated in a mountainous area, with...

, China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...

)
17.9
Thai
Thai people
The Thai people, or Siamese, are the main ethnic group of Thailand and are part of the larger Tai ethnolinguistic peoples found in Thailand and adjacent countries in Southeast Asia as well as southern China. Their language is the Thai language, which is classified as part of the Kradai family of...

 (in Singapore)
17.2
Southern Chinese (in Taiwan) 17.2
Chinese (in Hong Kong
Hong Kong
Hong Kong is one of two Special Administrative Regions of the People's Republic of China , the other being Macau. A city-state situated on China's south coast and enclosed by the Pearl River Delta and South China Sea, it is renowned for its expansive skyline and deep natural harbour...

)
16.3
Hakka
Hakka people
The Hakka , sometimes Hakka Han, are Han Chinese who speak the Hakka language and have links to the provincial areas of Guangdong, Jiangxi, Guangxi, Sichuan, Hunan and Fujian in China....

 (2)(Taiwan)
15.6
Guangzhou
Guangzhou
Guangzhou , known historically as Canton or Kwangchow, is the capital and largest city of the Guangdong province in the People's Republic of China. Located in southern China on the Pearl River, about north-northwest of Hong Kong, Guangzhou is a key national transportation hub and trading port...

 (China)
15.5
Northeastern Thailand 15.1
Minnan (Avg 1 & 2) (Taiwan) 15.0
Middle' Chinese (in Taiwan) 15.0
Hakka (Taiwan) 13.6
Wuhan
Wuhan
Wuhan is the capital of Hubei province, People's Republic of China, and is the most populous city in Central China. It lies at the east of the Jianghan Plain, and the intersection of the middle reaches of the Yangtze and Han rivers...

 (China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...

)
13.5
Maonan
Maonan
The Maonan people are one of the 56 ethnic groups officially recognized by the People's Republic of China. There are a total of 107,166 Maonan, mostly living northern Guangxi province in southern China....

  (Guangxi
Guangxi
Guangxi, formerly romanized Kwangsi, is a province of southern China along its border with Vietnam. In 1958, it became the Guangxi Zhuang Autonomous Region of the People's Republic of China, a region with special privileges created specifically for the Zhuang people.Guangxi's location, in...

 , China)
13.4
Chinese (in Singapore) 13.4
Vietnamese 13.2
Southern Han (China) 11.5
Shanghai (China) 11.2
Meizhou Han (Guangdong, China) 10.0
Shijiazhuang Tianjian Han (Beijing) 9.6
Guangzhou Han (China) 9.4
Thailand 9.2
Nu (Yunnan
Yunnan
Yunnan is a province of the People's Republic of China, located in the far southwest of the country spanning approximately and with a population of 45.7 million . The capital of the province is Kunming. The province borders Burma, Laos, and Vietnam.Yunnan is situated in a mountainous area, with...

, China)
9.0
Northern Chinese (in Taiwan) 8.6
Pazeh (Taiwan) 8.2
Aichi (Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...

)
7.6
Lisu (Yunnan, China) 7.2
Beijing (China) 6.8
Naxi (Yunnan, China) 6.1
Hui
Hui people
The Hui people are an ethnic group in China, defined as Chinese speaking people descended from foreign Muslims. They are typically distinguished by their practice of Islam, however some also practice other religions, and many are direct descendants of Silk Road travelers.In modern People's...

 (Qinghai
Qinghai
Qinghai ; Oirat Mongolian: ; ; Salar:) is a province of the People's Republic of China, named after Qinghai Lake...

, China)
5.9
Northern Han (China) 5.7
Japan (3) 5.0
Hyogo (Japan) 4.7
South Korea (3) 4.4
Man (Harbin City, China) 4.1
Siraya (Taiwan) 3.9
Central Japan 3.6
Linqu County (Shandong
Shandong
' is a Province located on the eastern coast of the People's Republic of China. Shandong has played a major role in Chinese history from the beginning of Chinese civilization along the lower reaches of the Yellow River and served as a pivotal cultural and religious site for Taoism, Chinese...

, China)
3.3
Timorese 2.6
Inner Mongolia (China) 2.0
Java
Java
Java is an island of Indonesia. With a population of 135 million , it is the world's most populous island, and one of the most densely populated regions in the world. It is home to 60% of Indonesia's population. The Indonesian capital city, Jakarta, is in west Java...

nese (in Singapore)
2.0
Oold (Mongolia) 1.9
Nivkhi (Sakhalin I, Russia) sland 1.9
Thao (Taiwan) 1.7
Riau Malay (in Singapore) 1.5
Tuva (2) (Russia) 1.4
Tibetan (China) 1.3
Khalkh  (Ulaanbaatar
Ulaanbaatar
Ulan Bator or Ulaanbaatar is the capital and largest city of Mongolia. An independent municipality, the city is not part of any province, and its population as of 2008 is over one million....

, Mongolia
Mongolia
Mongolia is a landlocked country in East and Central Asia. It is bordered by Russia to the north and China to the south, east and west. Although Mongolia does not share a border with Kazakhstan, its western-most point is only from Kazakhstan's eastern tip. Ulan Bator, the capital and largest...

)
1.2
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...

 (Hokkaidō
Hokkaido
, formerly known as Ezo, Yezo, Yeso, or Yesso, is Japan's second largest island; it is also the largest and northernmost of Japan's 47 prefectural-level subdivisions. The Tsugaru Strait separates Hokkaido from Honshu, although the two islands are connected by the underwater railway Seikan Tunnel...

, Japan)
1.0
Okinawa (in Hawaii, USA) 1.0
Indigenous (Taiwan) 0.9
Khalkha (Mongolia) 0.5
Brahui (Pakistan) 0.5

A2-Cw11(1)-B46

This haplotype is unique in several regards, first and most importantly the B46 serotype is not from Africa, this distinguishes it from every other known B serotype. It is the result of a recombination event between B62(B*1501) and an HLA-C allele within Asia. This event happened recently as there is only one major allele and minor alleles are at trace frequencies. There has been some recombination between this haplotype, A24 and A11 bearing alleles, probably in a local (or tribal population). B46 is found wherever Asian wet-rice farming peoples have traveled and is found at low frequencies in non-farming indigenous groups. The one exception is the Ninhvet of Siberia and the Eastern Tlinglet of Alaska. This B46 contribution appears to have been recent. Because of the numbers of people represented by the sample groups, and its relative high frequency in those group A2-B46 is one of the most frequent, if not the most frequent A-B haplotype in the world, even though it is absent from the indigenous populations of most peoples in the world.


HLA A2-B46 haplotype frequencies
freq Rank in
ref. Population (%) Pop.
Buyi 16.6 1 1
Miao 13.6 1
Singapore
(Chinese)
11.4 2
Chaoshan 10.1 1
Southern Han 7.8 2
VietNam 7.8 1
Thai 7.2 1
Thai Chinese 4.0
Japanese 3.3 4
Li 3.0
Korea 2.8
Uygar 2.7
Manchu 2.6
Inner Mong. 1.9
Northern Han 1.8
1 highest freq. A-B hap in Asia.


This haplotype is unique in several regards, first and most importantly the B46 serotype is not from Africa, this distinguishes it from every other major B serotype except B*48
HLA-B48
HLA-B48 is an HLA-B serotype. The serotype identifies the more common HLA-B*48 gene products. B48 is most common along the West Pacific Rim, Americas indigeonous peoples and Northern Eurasians...

. It is the result of a recombination event between B62
HLA-B62
HLA-B62 is an HLA-B serotype. The serotype identifies certain B*15 gene-allele protein products of HLA-B.B62 is largest of many split antigens of the broad antigen, B15. B62 best identifies the B*1501, B*1504, B*1507, and B*1525 allele products....

(B*1501
HLA-B15
HLA-B15 is an HLA-B serotype. The serotype identifies the B*15 gene-allele protein products of HLA-B.B15 is a broad antigen can be subdivided into several split antigens that are often used in characterization. These are B62, B63, B70, B71, B72, B75, B76, B77...

) and an HLA-C
HLA-C
HLA-C belongs to the MHC class I heavy chain receptors. The C receptor is a heterodimer consisting of a HLA-C mature gene product and β2-microglobulin. The mature C chain is anchored in the membrane...

allele within Asia. This event happened recently as there is only one major allele and minor alleles are at trace frequencies. There has been some recombination between this haplotype, A24 and A11 bearing alleles, probably in a local (or tribal population). B46 is found wherever Asian wet-rice farming peoples have traveled and is found at low frequencies in non-farming indigenous groups. The one exception is the Ninhvet of Siberia and the Eastern Tlinglet of Alaska. This B46 contribution appears to have been recent. Because of the numbers of people represented by the sample groups, and its relative high frequency in those group A2-B46 is one of the most frequent, if not the most frequent A-B haplotype in the world, even though it is absent from the indigenous populations of most peoples in the world.

The most common haplotype, and probably the ancestral haplotype given its distribution from the Ninhivet to Indonesia is:

A*0207 : C*0102 : B*4601 : DRB1*0901 : DQA1*0302 : DQB1*0303

A different haplotype that is more common in Korea and Japan is

A*0207 : C*0102 : B*4601 : DRB1*0803 : DQA1*0103 : DQB1*0601

B46, or a closely linked allele may have been under positive selection in rice farmers of Asia.
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