HLA-DR9 explained

human major histocompatibility complex, class II, DR9
Haplotypes groups	DQA*01:DRB1*0901 toDQA*01:DRB1*0906
Structure (See HLA-DR)
Identifiers	alpha *0101
Symbol(s)	HLA-DRA
EBI-HLA	DRA*0101
Identifiers	beta 1 *0901
Symbol(s)	HLA-DRB1
EBI-HLA	DRB1*0901
Shared data
Locus	chr.6 6p21.31

HLA-DR09 (DR9) is a HLA-DR serotype that recognizes the DRB1*0901 gene product.

Serology

DR9 recognition of some DRB1*0901 alleles^[1]

DRB1*	DR9			Sample
allele	%	%	%	size (N)
0901	95			1058

The serological reaction of DR9 is relatively good. The serology of DRB1*0902 to *0906 serotypes is unknown.

Disease associations

DRB1*0901: Early childhood myasthenia gravis^[2]

Extended linkage

DRB1*0901:DQA1*0301:DQB1*0303 haplotype: Early childhood myastenia gravis^[2]

Genetic linkage

DR09 Haplotypes
	DRA	DRB1
Haplotypes	0101	0901	0101
	DQA1	DQB1	DRB1
Haplotypes	0301	0303	0901
	HLA-A	HLA-B	DRB1
Haplotypes	0000	0000	0901

HLA-DR9 is genetically linked to HLA-DR53, and HLA-DQ3 and DQ9 serotypes.

Notes and References

1. http://www.ebi.ac.uk/imgt/hla/allele.html derived from IMGT/HLA
2. Shinomiya N, Nomura Y, Segawa M . A variant of childhood-onset myasthenia gravis: HLA typing and clinical characteristics in Japan. . Clin Immunol . 110 . 2 . 154–8 . 2004 . 15003812 . 10.1016/j.clim.2003.10.004.