PT - JOURNAL ARTICLE AU - Mariana Matioli da Palma AU - Maurício E Vargas AU - Amanda Burr AU - Rui Chen AU - Mark E Pennesi AU - Richard G Weleber AU - Paul Yang TI - Variable expressivity of <em>BEST1</em>-associated autosomal dominant vitreoretinochoroidopathy (ADVIRC) in a three-generation pedigree AID - 10.1136/bmjophth-2021-000813 DP - 2021 Oct 01 TA - BMJ Open Ophthalmology PG - e000813 VI - 6 IP - 1 4099 - http://bmjophth.bmj.com/content/6/1/e000813.short 4100 - http://bmjophth.bmj.com/content/6/1/e000813.full SO - BMJ Open Ophth2021 Oct 01; 6 AB - Objective Autosomal dominant vitreoretinochoroidopathy (ADVIRC) is associated with pathogenic variants in BEST1, which typically causes visual impairment in the late stage of disease. We present a pedigree with variable expressivity and the youngest case in the literature with visual impairment in early childhood.Methods and analysis This is a retrospective, observational, case series describing multigenerational members of one family affected with ADVIRC. Patients underwent examination, ultra-widefield fundus photography and angiography, optical coherence tomography, full-field electroretinography (ffERG) and full-field perimetry.Results Three affected members of the pedigree, one from each successive generation, were found to harbour a mutation, c.715G&gt;A:p.Val239Met, in BEST1. The proband characterised in this report is, to our knowledge, the youngest documented case of ADVIRC in early childhood. Yet, this patient has the most severe retinal dysfunction compared with the father and paternal grandmother, whom exhibit classic characteristics of ADVIRC. Longitudinal data from the paternal grandmother showed that there was a rapid decline in ffERG responses (photopic decline worse than scotopic) from the fourth to fifth decade of life, which correlated with severe concentric constriction of visual fields.Conclusion This multigenerational case series provides new insights into the ADVIRC disease spectrum and rate of progression. While ADVIRC typically causes a slowly progressive disease, we show that variable phenotypic expressivity is possible among affected members of the same family with the same mutation in BEST1. Thus, ADVIRC must also be considered in the differential diagnosis of paediatric patients with severe retinal dystrophy in early childhood.Data are available upon reasonable request. Data availability statement: Dare available upon reasonable request.