RT Journal Article
A1 Sigurdsson, H
A1 Helgadottir, G
A1 Magnússon, KP 
A1 Jonasson, F
A1 Sigurdsson, AG 
A1 Viggosson, G
A1 Sverrisson, T
A1 Gíslason, I
A1 Stefansson, E
T1  Geographic Atrophy in Age Related Macular degneration: Clinical Features and Genealogy 
JF Investigative Ophthalmology & Visual Science
JO Invest. Ophthalmol. Vis. Sci.
YR 2002
VO 43
IS 13
SP 2498
OP 2498
SN 1552-5783
AB     Purpose: We have previously demonstrated a familial pattern in age related macular degeneration (AMD) in Iceland using the Icelandic genealogy database. We now report on the genealogy of geographic atrophy (GA) in Iceland using the Icelandic genealogy database; and the relationship between familial patterns and clinical features in GA. Method: We have recruited 761 AMD patients and 1045 of their unaffected relatives for eye examination. Both eyes underwent thorough eye examination, fundus photography and classification according to international classification and grading system (The International ARM Epidemiological Study Group (Bird et al, Survey Ophthalmol, 39, 367 - 374, 1995). The Icelandic genealogy database was used to analyze the ancestral pattern of AMD and the phenotypic subtypes. Results: Of the 1806 individuals examined, 261 had geographic atrophy in at least one eye and of these 175 (67%) had GA in both eyes, 42 individuals had visible drusen (24%) and 37 (21%) exudative AMD . In 86 individuals with apparent unilateral GA, 29 (33%) had exudative AMD in the other eye. The geographic atrophy population has relatively fewer ancestors in each generation compared to control groups of Icelanders and also compared to all AMD patients, early AMD and exudative AMD. If we trace 213 GA patients 12 generations back, we find a single common ancestor, a woman borne in 1430 in Iceland. Conclusion: Geographic atrophy has a strong familial pattern in Iceland and this seems to be even stronger than for other forms of AMD. GA patients have more ancestors in common and therefore fewer forefathers than other AMD groups and Icelanders in general. The population with geographic atrophy has a common foremother in the 15th century.    
RD 3/6/2021