Butterfly shaped macular dystrophy was first described by Deutman et al. in 1970.¹ It is characterised by bilateral accumulation of pigmented or yellowish material at the level of the retinal pigment epithelium. Lesions consist of 3–5 “wings,” which resemble the wings of a butterfly. Affected patients present with a subnormal electrooculogram and normal or slightly diminished visual acuity. The disease is relatively benign, but it can progress with age to chorioretinal atrophy in the parafoveal and peripapillary regions.² Butterfly shaped macular dystrophy shares important similarities with age related macular degeneration—the most common cause of blindness in older patients.^3,4 In both diseases, abnormal deposition of lipofuscin like material at the level of the retinal pigment epithelium is found, which results in loss of the overlying photoreceptors.²

Butterfly shaped macular dystrophy has an autosomal dominant inheritance pattern. To date, it has been associated only with mutations in the peripherin/RDS gene.^5–12 We ascertained members of the family with butterfly shaped macular dystrophy that was described originally by Deutman et al. in 1970,¹ and we excluded peripherin/RDS as the causative gene in this family.² In addition, we excluded the ROM-1 gene; four genes expressed in cone photoreceptors; all known non-syndromic macular, retinal pigment epithelium, and choroidal dystrophy loci; all known Leber congenital amaurosis loci; and all known non-syndromic congenital and stationary retinal disease loci.² This study aimed to identify the locus responsible for butterfly shaped macular dystrophy in this family with a genomewide linkage scan.

PARTICIPANTS AND METHODS

Patients and ophthalmic examination

We previously ascertained 13 members (eight affected and five unaffected) of a Dutch family with butterfly shaped macular dystrophy that was first described in 1970 by Deutman et al.^1,2 Ophthalmic examination of the participating family members included best corrected Snellen visual acuity, slit …