Background: We describe a Sicilian family in which optic disc drusen, angioid streaks, and mottled fundus--without dermatological signs of pseudoxanthoma elasticum (PXE)--are present in various combinations and segregate as an autosomal dominant trait. Since these ocular manifestations can be part of the clinical signs of PXE, we examined the possible involvement of a mutation in the ABCC6 gene, which is known to be responsible for PXE.
Methods: Linkage analysis was performed with both intragenic and flanking markers. We used marker D16B9722 and a single-nucleotide polymorphism located in exon 15 of the ABCC6 gene. LOD score values were calculated on the assumption of a gene frequency of 0.0001 and both complete penetrance and reduced penetrance (90%), with theta values between 0.0 and 0.4.
Results: LOD score values excluded the involvement of the ABCC6 gene.
Conclusions: The dominant transmission of optic disc drusen, mottled fundus, and angioid streaks in this family is not due to alterations in the ABCC6 gene.