The inheritance of pseudoexfoliative glaucoma (PEX) on the island of Gozo.

Abstract

Abstract: : . Purpose: To determine the mode of inheritance of pseudoexfoliative glaucoma in large families on the island of Gozo (Malta), lying south of Sicily. The distribution of PEX is primarily in Scandinavia and Northern Europe, however it is the third commonest cause of open angle glaucoma in the world. Because of the late age of onset, it is difficult to ascertain large families. Methods: The three pedigrees all demonstrated dominant inheritance from an affected deceased father, to adult offspring of both sexes. The families were composed of one living affected generation only, although the third generation under the age of 50 are under regular surveillance. Full eye examination was performed enabling classification of members over 50 as affected or probably unaffected. Twenty ml EDTA blood samples were taken for linkage studies. Results : One family had glaucoma and cataract associated with PEX; the second family had glaucoma and PEX; the third family had isolated PEX. All had onset over the age of 50. Of a total 21 adult siblings in the three families, 18 were affected ( 10 males, 8 females) and three were unaffected. All but one of the affected patients had bilateral involvement. Associated disorders, especially vascular events, were not reported. Occupations were largely sedentary. The three families are not knowingly related or consanguineous. One family originates from Rhodes in Greece. Conclusions: The pattern of inheritance of PEX in three families from Gozo is autosomal dominant with onset over the age of 50. Their PEX is associated with glaucoma and cataract but not with vascular events. Linkage studies to loci discovered elsewhere in PEX families will elucidate the genetic basis and possible heterogeneity in this common type of open angle glaucoma.

Keywords: genetics