Abstract
Purpose::
The etiology and genetic cause of idiopathic perifoveal telangiectasia is unknown. It is also not clear, if this phenotype represents a separate disease entity, or is a subphenotype of disorders with similar clinical presentation. As the first attempt to define the genetic factors underlying the disease, we screened a cohort of patients affected with bilateral acquired perifoveal telangiectasia for variation in the ATM gene responsible for ataxia telangiectasia.
Methods::
Twenty-nine patients diagnosed with bilateral acquired perifoveal telangiectasis (Yannuzzi classification: Type II) were enrolled and underwent standard ophthalmologic evaluation including visual acuity testing, fundus examination, stereo fundus photography and fluorescein angiography. All patients answered a standardized questionnaire including questions regarding smoking habits, medical and family history. Blood samples were obtained and isolated DNA screened for variation in the ATM gene by a combination of DHPLC and direct sequencing.
Results::
Nineteen female and 10 male patients with an average age of 59 years (range 39-76 years) and a median visual acuity of 20/50 were evaluated. Six patients described themselves as of Asian-Indian origin, one as of Hispanic origin and the remainder (22) as of European-American ancestry. Five patients had a family history of ocular telangiectasis or macular degeneration. Eight of 29 patients (28%) had been previously diagnosed with diabetes mellitus, 18/29 patients (62%) had been diagnosed with hypertension and 12/29 patients (41%) had a history of current or past smoking. Only 4 patients (14%) had no history of potential "vascular" risk factors. Potentially disease-associated variants in the ATM gene were identified in 59% of patients (13/22) of European-American ancestry. No such changes were identified in patients of Asian or Hispanic origin.
Conclusions::
Patients with bilateral acquired perifoveal telangiectasis of European-American ancestry present with high frequency of possible disease-associated ATM gene variation. In addition, vascular risk factors such as hypertension, diabetes and smoking may play a significant role in the development of the disease.
Keywords: macula/fovea • genetics • candidate gene analysis