Birdshot retinochoroidopathy (BSRC) is a rare, chronic, bilateral, posterior uveitis characterized by distinctive, multiple, hypopigmented choroidal and retinal lesions. Blurred vision and floaters are the most prevalent visual symptoms. Patients may also report dyschromatopsia and poor contrast sensitivity. Macular edema or atrophy is the most common cause of decline in visual acuity and 10% of patients are legally blind. Middle aged Caucasians of northern European extraction are most commonly afflicted. The pathogenesis is unknown, but HLA-A29 positivity appears to confer predisposition, and retinal autoimmunity seems to play a role. Vascular disease, sarcoidosis, psoriasis, autoimmune sensorineural hearing loss, and vitiligo have been reported in birdshot patients.
The relative risk of BSRC among HLA-A29-positive individuals has been estimated to be 50 to 224, and most investigators recognize the presence of the HLA-A29 allele as a necessary criterion for BSRC diagnosis for research purposes. HLA-A29 is present in as many as 7% of Caucasians, and is subdivided into more than 20 subtypes.
GENVINSET HLA A29 is a kit for the determination of the HLA-29 group of alleles, by Real Time PCR using TaqMan® probes technology.