Three Families With Best’s Disease and Normal Electro-Oculogram Recordings

Abstract

Purpose: : To describe 3 families with Best’s disease, normal electro-oculogram (EOG) and without VMD2 mutations.

Methods: : Evaluation of the patients included visual acuity, fundus and autofluorescence (Heidelberg Retinal Angiograph), Goldmann visual fields, optical coherence tomography (Zeiss, OCT3), full field (ISCEV protocol) and multifocal electroretinograms, and EOG. The diagnosis of Best’s disease was based on autosomal dominant inheritance, typical yellowish, autofluorescent material in the central macula accumulating beneath the retinal pigment epithelium, and decrease of the EOG Arden ratio.

Results: : Among the 1130 families with various retinal dystrophies followed up in Montpellier, 40 (3.5%) were found with vitelliform macular dystrophy. Best’s disease was observed in 20 of them while 13 families had adult macular vitelliform dystrophy and 7 had reticular dystrophy. In the group with Best’s disease, a normal EOG was recorded in 3 families. None of these 3 families carried mutations in VMD2 or RDS, and linkage to the VMD2 locus was excluded in one of them.

Conclusions: : In patients with Best’s disease and VMD2 (bestrophin) mutations, the decreased response of the EOG is attributed to an abnormal transepithelial chloride transport. However, the observation of families with normal EOG and no VMD2 mutations suggests that other genes are responsible for Best’s disease which could not impair the ionic transport but yet lead to similar subretinal deposits.

Keywords: retinal degenerations: hereditary • electroretinography: clinical • retinal pigment epithelium