HLA-DQ9 is a human leukocyte antigen

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...

 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...

 within the HLA-DQ

HLA-DQ

HLA-DQ is a cell surface receptor type protein found on antigen presenting cells. DQ is an αβ heterodimer of the MHC Class II type. The α and β chains are encoded by HLA-DQA1 and HLA-DQB1, respectively. These two loci are adjacent to each other on chromosome 6p21.3. Both the α-chain and β-chain...

 (DQ) serotype group. DQ8 is a split antigen of the DQ3

HLA-DQ3

HLA-DQ3 is a broad serotype category with split antigens HLA-DQ7, DQ8, and DQ9. Historically, originally recognized as MB3 a DC4 serotype, DQw3 was one of three early determined antigens recognized as HLA-DQ along with HLA-DQ1 and HLA-DQ2...

 broad antigen. DQ8 is determined by the antibody recognition of β⁹ and this generally detects the gene product of DQB1*0303.

Serology

DQ2, DQ3, DQ7, DQ8, and DQ9 recognition of DRB1*0303 product

	DQ9	DQ3	DQ2	DQ7	DQ8	sample
	%	%	%	%	%	(N)
	67	12	11	1	1	2563
Red indicates the level of 'false' reaction in non-DQ9 serotypes
Alleles link-out to IMGT/HLA HLA Informatics Group The HLA Informatics Group is a research group at the Anthony Nolan Research Institute that develops, runs and maintains the IMGT /HLA Database and the IPD...  Databease at EBI European Bioinformatics Institute The European Bioinformatics Institute is a centre for research and services in bioinformatics, and is part of European Molecular Biology Laboratory...

The serotyping efficiency of DQ9 is poor. The recognition of DQB1*0303 by DQ9 and or DQ3 is poorest, DQ2

HLA-DQ2

HLA-DQ2 is a serotype group within HLA-DQ serotyping system. The serotype is determined by the antibody recognition of β2 subset of DQ β-chains. The β-chain of DQ is encoded by HLA-DQB1 locus and DQ2 are encoded by the HLA-DQB1*02 allele group. This group currently contains two common alleles,...

 which recognizes a different DQB1 subgroup recognizes DQB1*0303 as efficiently as DQ3. For this reason DQ9 serotyping is a poor method of typing for transplantation or disease association prediction or study.

DQB1*0303

(DQ9) is associated with nasal polyps, gestational diabetes

Gestational diabetes

Gestational diabetes is a condition in which women without previously diagnosed diabetes exhibit high blood glucose levels during pregnancy . It is widely accepted as a disease only in the United States, there is some question whether the condition is natural during pregnancy...

, microscopic polyangiitis (Japanese). Primary linkage is with DRB1*0901-DQB1*0303

DQ9.3

DQA1*0302:DQB1*0303 maybe associated with juvenile diabetes in the orient.
(Chinese) Primary linkage of vitiligo

Vitiligo

Vitiligo is a condition that causes depigmentation of sections of skin. It occurs when melanocytes, the cells responsible for skin pigmentation, die or are unable to function. The cause of vitiligo is unknown, but research suggests that it may arise from autoimmune, genetic, oxidative stress,...

is with DQA1*03-DQB1*0303